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12 wire on a 40 amp breaker,

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sometimes Brian Orr. Hello,

1:30

hello, this is the HVAC School Podcast. I'm

1:32

Brian with the flu, which is why my

1:34

voice sounds like this. And you're

1:36

going to notice that probably a couple of the intros, if a couple

1:38

of the podcasts, I sound like

1:40

this. That's because a little secret

1:42

of how the sausage is made. I

1:45

do these in batches and unfortunately I got

1:48

way behind and now I have to do it when

1:50

I have no voice. Anyway, going to try

1:52

to stick with the sexy late night

1:55

DJ voice here so that I don't wear

1:57

it out. Hopefully that's working

1:59

for you. Anyway, today

2:01

we're talking about expansion valves. What does

2:03

and doesn't matter. We have a really

2:06

great panel of people to talk about that.

2:08

Matthew Taylor, who is the

2:10

director of refrigeration service for

2:12

Kalos. Corey Cruz, who is

2:14

a refrigeration service tech at Kalos. And then

2:16

Joe Shearer. You all know Joe. Joe is

2:18

a really brilliant technician and business

2:20

owner himself, as well as our regular cast, Matt

2:22

Berner and Adam Mufic. This

2:25

is a republish of a live stream. We're going to

2:27

do a couple of these because we've had a couple

2:29

great conversations that some of you probably missed. I

2:31

think you'll enjoy it. What

2:33

does and doesn't matter about expansion

2:35

valves. So

2:37

we are here once again on

2:40

our live stream. We're back, back in action, or at least, I

2:42

mean, you guys have been, but I've been missing a few. So

2:45

it's good to see all your smiling

2:47

faces again. Today we're going to talk

2:49

about expansion valves, specifically TXVs or TEVs.

2:52

And our guests today are, we actually have

2:54

two Kalos people here today. Corey Cruz, who

2:56

is a market refrigeration tech with

2:59

us and also a superstar

3:01

on TikTok at Bad TXV. That's why

3:03

we had to have you on on

3:05

a topic about TXVs. And

3:07

Matthew Taylor is our head

3:09

of refrigeration service, director of refrigeration service

3:12

at Kalos and had

3:14

a great presentation at the symposium, which I would encourage

3:16

all of you to get the virtual ticket and go

3:18

watch. And then Joe Shearer

3:20

with Precision Air Conditioning. Joe is a long

3:22

time contributor and also

3:24

a TXV aficionado. So

3:27

thanks for joining, guys. Thank you for having us. Indeed.

3:29

When you have so many people and you don't know how to like, how do you

3:31

all talk at once? But anyway, so I want

3:33

to jump right into it. And I'm actually just going

3:35

to start with actually, first off, am I the host

3:38

here or somebody else expecting the host? I didn't ask

3:40

the question. You're the host. I'll just do

3:42

it. It's fine. So I wanted to jump

3:44

in with Joe because one of the first

3:46

things that I want to try to bust

3:48

is any myth surrounding TXV. Just

3:51

give some nuggets right off the bat. So

3:53

is there anything that a lot of

3:56

people think is really important in terms

3:58

of expansion valves that maybe isn't? as

4:00

important off the top of your head. We'll go

4:02

around the horn here, but anything that's like everybody

4:04

has in there, like this absolutely has to be

4:06

this way, but actually maybe isn't as important in

4:08

your experience. Start with you, Joe. Yeah,

4:10

I'd say clocking the bulb. I'm

4:12

a residential light

4:15

commercial technician, so these are

4:17

not giant refrigeration lines. Maybe

4:19

more important then, but I think

4:22

that's not super important. I

4:24

think maybe, and even going

4:27

horizontal manufacturers will say

4:30

horizontal is always preferred, but I don't

4:32

see a huge difference in making one be

4:35

vertical or horizontal personally

4:37

either. It certainly is not going to fix

4:39

a problem that you come

4:42

across if it's underfeeding or overfeeding. It's

4:44

probably more of a contact with the

4:46

pipe issue more than where

4:48

it's positioned on the pipe as far as the

4:50

clocking of it goes. Yeah, we really are starting

4:53

right in the center here, but I like it. Matthew,

4:55

I'm going to go to you. Anything that guys get

4:57

really fixated on that maybe isn't as important as they

4:59

think it is? There's

5:01

a couple things in the refrigeration world.

5:03

One of them is insulating that bulb.

5:05

If you're coming from the residential world

5:07

or a commercial AC, that bulb is

5:09

probably sitting in an ambient environment and

5:11

really does need to be insulated very

5:13

well. Whereas if that bulb is in

5:15

a refrigerated case where the TD is

5:18

six degrees or something like that from

5:20

coil to supply air, not

5:22

really all that critical. In

5:24

fact, it's hardly ever even done. I do

5:27

see a lot of folks really getting fixated

5:29

on that. Then the second is not

5:31

setting your superheat until you make temp.

5:33

We see that too. We see techs

5:36

try to run this system and not

5:38

really worry about superheat until they get

5:40

real close to temp and then dial

5:42

it in. In refrigeration, that's going to

5:44

be a 40, 50 degree swing sometimes,

5:46

maybe even more. The superheat will change

5:48

from 50 to 10 to temp, one

5:51

or two degrees. It's really, really minor.

5:53

It's not going to be a major

5:55

deal. Go ahead and dial it in so

5:57

you can pull down much faster. You

6:00

want to come back and put the final touch on there

6:02

because that one degree or two degrees matters. No,

6:04

but that's when I see quite a bit. People just

6:06

holding off forever to dial that super eight in.

6:08

Go ahead. So

6:11

Joe took my answer for sure, but I

6:13

completely agree. I think as long as you're

6:15

not mounting the sensing bulb at six o'clock,

6:18

which it should never be under any

6:20

size line or anything, typically

6:22

you'd be fine unless you have a

6:24

very large fight. But I think that

6:27

as long as the bulb is making

6:29

good contact with the pipe, sanded, including

6:31

the straps, no zip ties, use

6:34

the straps that are provided or something that is going to

6:36

hold it tight and conduct that heat well, you'll

6:38

be fine. I think those three things that were

6:40

mentioned as far as off the top of my

6:42

head, I can think of pretty

6:44

much cover it. It's a mystical valve, but

6:46

there's really not much to it. If

6:49

everything is set as

6:51

the manufacturer specifies. Now

6:53

let's do that now then. Let's go into a

6:55

little bit about just the basics of how the

6:57

valve works. I'll look for a volunteer. Anybody want

6:59

to take that? The basics of the valve and

7:02

the forces that affect it. Now

7:05

you're going to make me call on you. Okay.

7:07

Fine. Matthew basics of an expansion valve

7:09

and the forces that affect it. All

7:12

right. So yeah, what we've got going

7:14

on here, we've got a solid column

7:16

of hopefully sub cooled at

7:18

least a tiny amount refrigerant coming on

7:20

the inlet side of our

7:22

expansion valve. Now on our outlet,

7:24

we're going to be sensing the

7:27

evaporator pressure suction pressure on the opposite

7:29

side of that. There's going

7:31

to be a mechanism, whether it's an externally

7:33

equalized or not, that is

7:35

going to bring that pressure. That

7:37

outlet pressure is going to

7:39

push on, on the diaphragm. We're

7:42

going to use the temperature inside the bulb.

7:44

There's going to be some type of refrigerant

7:46

in that bulb. It's going to increase its

7:49

pressure based on its PT chart. Right. So

7:51

when it's sensing a temperature, it's going to

7:54

increase or decrease the pressure based on that

7:56

temperature. That's the bulb that we're talking about

7:58

strapping. So it's got a. measure that

8:00

temperature really, really well. It's going

8:03

to add that pressure to the top of

8:05

that diaphragm. So then we've got

8:07

to offset the difference and that's going to be

8:09

the spring and if it's a

8:11

manual adjustment, that's where we'll add that pressure

8:13

that will add to that evaporator pressure. Again,

8:15

they've got to equal, they've got to balance.

8:18

Then when our sensing bulb adds just a little bit of

8:20

pressure, it's going to push down that spring a little bit.

8:22

That's going to open our orifice. My pin is going to

8:24

move out of a hole and it's going

8:26

to allow just a little more refrigerant through there. Well,

8:29

when that refrigerant comes out of our evaporator

8:31

on supply line or suction line, it's

8:33

going to be colder. So we're going to remove some of that heat

8:36

from our bulb. Our bulb's refrigerant inside

8:38

because of its PT chart is going

8:40

to have a little less pressure and

8:42

that's going to cause that needle to

8:44

rise into the hole a little bit

8:47

farther, reducing the amount of refrigerant flow

8:49

we get. So the concept here is

8:51

obviously we're going to regulate the refrigerant

8:53

flow through that evaporator

8:55

by measuring how much superheat we

8:57

have on the outlet side. That's going to be

8:59

the net effect of this whole thing. The

9:02

way I always talk about it because obviously this

9:04

illustration is one of the best there is in

9:06

terms of showing the different balancing forces, but

9:08

it's measuring superheat and the exact same way that we do

9:10

it when we take a pressure and we take a temperature,

9:13

we'd use a clamp and we take a temperature on the

9:15

suction line and we'd use a gauge

9:17

or hopefully nowadays some sort of probes

9:19

or digital gauges and we measure that

9:21

PT relationship there we compare the two

9:24

and that's what gives us our superheat,

9:26

our temperature above saturation or evaporator temperature

9:28

to use or refrigeration terminology. But

9:31

one of the things that I think a lot of people

9:33

get confused about is they almost think that there's like a

9:35

brain in here or something when really it's just a balance

9:37

of forces like you just described.

9:40

I wanted to ask the question about

9:42

that external equalizer though because I think

9:44

external versus internal. Where do

9:46

you see more internally equalized valves and

9:48

where do you see more externally equalized

9:51

valves and I'll stay with you there

9:53

Matthew. The purpose of our equalization line

9:55

really is to measure how much

9:57

pressure drop resistance we

10:00

have to that refrigerant flow through the

10:02

evaporator. So what we're going to do is

10:04

if we've got a heavy amount of drop,

10:06

we've got a really big coil, for instance,

10:09

our pressure coming out of the other side is not

10:12

going to be the same. We're going to have a pressure drop there.

10:14

Well, if we don't account for that, like

10:16

you just said, our TXD is calculating our

10:18

superheating, well, it's using the wrong pressure to

10:20

do that. So it's going to do it

10:23

inaccurately. So we want that

10:25

external equalizer to show us that offset

10:27

and to calculate really the superheating at

10:29

the fault. That's the point. So

10:31

when would we not use it? When

10:33

we don't have a lot of locks,

10:35

a very small evaporator coil would be

10:37

a perfect example of that. In a

10:40

lot of our applications, we're going to

10:42

see distributor tubes, right? Well, each of

10:44

these distributors is basically creating a small

10:46

evaporator. That's what it's doing. Well, anytime

10:48

we see distributor tubes, there's a question.

10:50

We may have a big enough evaporator.

10:52

We need to have an external.

10:55

If we don't have a distributor tube,

10:57

there's a real good chance we're not

10:59

going to see an equalizer there because it's

11:01

a pretty small coil. So that's going to be the

11:04

reason. And actually, that's a really good

11:06

point that you brought up about that distributor, is

11:08

that in part of the coil design, that distributor

11:10

also adds a pressure drop in addition to the

11:13

valve itself. I mean, you saw this a lot

11:15

like with piston systems, where you would have a

11:17

system that didn't have an orifice in it at

11:19

all, and you would still have a pretty significant

11:22

pressure drop. And that's because it's not just the

11:24

orifice that's producing that pressure drop. It's also pressure

11:26

drop to the distributor. I mean,

11:28

you will see that. So I want to

11:30

go back to Joe. Matthew was talking a

11:32

little bit about adjustable valves. Is there ever

11:34

a case in residential where adjusting a valve

11:36

is something that you have done or that

11:39

you see somebody needed to do? Oh, yeah,

11:41

100%. One brand in particular, a

11:44

lot of their valves come adjustable, and

11:47

they all seem to run really

11:49

low superheat. So I'm usually adjusting

11:51

those. Mike commercial, I'll say

11:53

the first thing to do maybe

11:56

is we could talk about that for just a

11:58

second. Your most common... thing

12:00

that you'll probably find on a

12:02

TXV is low superheat. You're not

12:04

going to really find high

12:07

superheat and fix

12:09

that with clamping the bulb or

12:11

adjusting it. I'll say typically because

12:14

it could have been adjusted before

12:16

but usually you'll find that it's

12:18

low and nine times

12:20

out of ten it's probably that the

12:22

bulb is not getting good contact or clamp

12:25

tightly to the line and start

12:27

there and make sure it's 100% and

12:30

then start adjusting the valve from there.

12:33

But yeah you do see it. I think

12:35

you would say at one point that it was a particular

12:37

brand in their heat mode expansion valves was where you saw

12:39

it more so is that right? Really

12:41

both equally it seems like they come out of

12:43

the box set pretty low maybe on

12:46

purpose but yeah I've run into

12:48

somewhere just by better

12:50

mounting the bulb and insulating it you can actually

12:52

if it is uninsulated or poorly insulated sometimes that

12:54

will solve that issue but again be careful and

12:57

this is just a note to resi text if

12:59

a valve is not adjustable you don't want to

13:01

go trying to take the bottom off that valve

13:03

because it'll boing on you that's the technical term

13:06

you don't want to boing in valve. That last

13:08

thread's a doozy honey. That last

13:10

one's a doozy. I've actually seen that in

13:17

a supermarket recently I went to go and

13:19

set superheat on cases and it was an

13:21

older store and they had a bunch of

13:24

what looked like a little acorn nut on there and it looked

13:26

like you could adjust it and right before

13:28

I was about to crack and I had the

13:30

backer wrench and I had my crescent wrench another

13:32

hand I'm about to take it off there's a

13:34

sticker on there it says do not remove this

13:36

tab you will lose the system charge and the

13:39

system charge is probably over a thousand pounds on

13:41

that rack so yeah definitely more

13:43

often than not in commercial refrigeration obviously they're

13:45

going to be adjustable but there are some

13:47

particular cases you always want to make sure

13:49

when you're looking at that valve you

13:52

know that it is adjustable or you

13:54

will lose the system charge and everything

13:56

that's inside of that body yeah

13:58

so on the list of things that are very important knowing

14:01

whether it's adjustable valve or not is on

14:03

the list of very important things. Let's

14:05

transition to that. Let's just talk through this

14:07

a little bit. We'll sit with you, Cory.

14:10

What are some of the things in terms

14:12

of solving issues with valves, but also the

14:14

installation of systems initially to ensure that you

14:16

don't have valve issues? Just rattle off your

14:18

list of things that you see as being

14:20

very important. As far as installation

14:22

is concerned? It could be installation, but it could also

14:24

be just things that you see on the service side

14:26

and just best practices. Yeah, so

14:28

obviously everybody knows what the first one's going

14:31

to be. You need to be flowing nitrogen

14:33

while you're bracing. You

14:35

also need to be taking extra

14:37

precaution in that diagram right there. You

14:39

see the illustration. In the top

14:42

right corner, they have a wet rag covering the

14:44

valve. If you have a brass

14:46

body TXV, you definitely need to be protecting

14:48

it from heat. You don't want to be

14:50

melting any of the components inside or warping

14:53

them, especially those who

14:55

like to use the rosebud a lot.

14:57

It's very easy to do that. The

15:00

stainless steel ones you'll see sometimes are

15:02

supposedly less heat conductive. So they say

15:04

you don't need to wrap it.

15:06

I personally wrap them all because

15:09

why not? It takes an extra two

15:11

seconds and you'll avoid a lot of

15:14

problems. Another thing you need to take

15:16

into consideration is the application. If you're

15:18

making sure you have the right valve

15:20

for the job. So that typically you

15:22

can get from the manufacturer. If

15:25

you're dealing with spoiling valves, you can

15:27

reference the spoiling. I think it's a 1010

15:29

bulletin, which will help size that.

15:33

And we were joking earlier, but orientation of the

15:35

valve is funny as that is. I

15:37

have actually put in an expansion

15:40

valve backwards before and I took a

15:42

picture of it all proud and ready

15:44

to go. Look what I did. Only

15:46

to realize, huh, and I don't mean

15:48

one valve. It was a

15:50

20 ton air handler and

15:53

split five tons each

15:55

and four circuits and every

15:57

single one of them I put in backwards. It's

16:00

such an obvious thing, but especially

16:02

if there's not much of a

16:04

difference in the height of the valves, it can

16:06

get confusing. And when you're rushing and throwing things

16:08

together and piping things in, I'm telling you it

16:11

happens. What's the best way to actually tell the

16:13

direction of flow through a valve? Look

16:16

at the arrow. There will typically be an

16:18

arrow or usually like it's

16:20

not a hundred percent pull proof. So

16:22

you always got to make sure, however, typically

16:24

your inlet is going to be higher than

16:26

the valve that I've recently seen as well

16:29

with solenoids and stuff. That's not always

16:31

the case. It depends, but that's how

16:33

I've always thought of it in my head. So

16:36

Joe, one question that I had on

16:38

the bulb side, when you're installing a

16:41

valve or working on a system, like

16:43

maybe brazing in an air handler or

16:45

something, do you remove the bulb when

16:48

you're brazing near it or do you wrap it or

16:50

neither? So the bulb itself, not the valve.

16:53

I'll definitely protect it from heat, but

16:55

I won't always remove it.

16:57

But if you're newer at brazing

17:00

and maybe staying on a joint a little

17:02

longer than you should, then I would probably

17:04

recommend removing it completely. But

17:06

my rule of thumb is usually if

17:08

it's factory installed and I

17:10

usually got some foam tape or even

17:13

sometimes there'll be a little sticker inside

17:15

the air handler that if

17:17

you're not starting to melt that, then you're okay

17:19

as far as the valve goes. This illustration here

17:21

is nice. It shows you some max

17:24

temperatures and it's really not that hot. The

17:27

different areas of these valve is 210

17:29

degrees is not, I think even if

17:31

you wrapped it, you would maybe be

17:33

approaching that, especially on sometimes

17:36

the outlet, if it's close

17:38

to a brass nozzle, those can

17:40

be low can tankers sometimes to get the

17:43

flow nicely. So you may stay on that

17:45

one a little longer than you were hoping

17:47

for. So probably personally, I would recommend a

17:49

little bit of the wet rag paste and

17:51

then wrap that with an

17:53

actual wet rag And make

17:55

sure that paste is really packed in tight

17:57

around the valve as well, not loose. Only

18:01

or doesn't agree with that were the double

18:03

wet rag heads the summer when right hand

18:05

and I'd put the where I go around

18:08

the wet rag. Yeah, yeah, I saw success.

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Could get schooled and check out for an awesome

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discount. Census. The. Scale

19:42

is the heavyweight champion. So.

19:44

Joe while I still have you we had this

19:46

question was I thought was interesting one because this

19:49

is another one of these. Is it helpful? Isn't

19:51

it? How for putting the ball? Been hot water

19:53

heating up the bob in your hand as a

19:55

troubleshooting tool. Would he think about that? The ice

19:57

water the hand thing. i wouldn't say it's

20:00

as much as I would say like last-ditch

20:02

effort, can we make it open a little

20:05

more because even if the,

20:07

let's say you're troubleshooting a valve, so you've got

20:10

low suction pressure along with low

20:12

superheat because I do think a

20:15

lot of people misdiagnose expansion valves

20:17

when they see low suction

20:19

pressure, even though it correlates along with

20:22

low superheat or maybe normal

20:24

superheat, but they still diagnose the bad

20:26

expansion valve when it's doing

20:28

the job properly. So if you were looking

20:30

at a system like that and you stuck

20:33

the bulb in hot water and it raised

20:35

your suction pressure and floated the compressor even

20:37

more, is that helping you

20:39

troubleshoot anything, right? I've seen it

20:41

where maybe you do truly have

20:43

a valve failing. It

20:46

would have to be one specific problem with the

20:48

valve to make that work, which

20:50

is losing its

20:52

refrigerant charge or its diaphragm

20:54

pressure because other mechanical

20:56

issues can help. That really won't

20:59

drive the valve open anymore. Rare

21:02

cases, I've seen it to where, yeah, your

21:04

suction pressure comes up a little bit

21:06

higher and then you get a little

21:08

more delta T and you

21:10

may even do some crazy things like strap it to

21:13

a discharge line and keep it

21:15

temporarily. Oh, here's

21:17

a good one. This is so I'm not noting that.

21:20

I want Matthew to weigh in on this one, on

21:22

this question. But then also, I'm going to start with

21:24

the question, Matthew, have you ever pressurized

21:26

the bulb with nitrogen in order to

21:29

temporarily get it set? I've

21:31

seen people do that. I've never actually done it. So

21:34

I've done it for testing purposes. I haven't done

21:36

it in the field to actually make something work.

21:38

I'm actually older than that. We started out in

21:40

the day with the dime under the head. Oh,

21:43

yeah. Probably shouldn't be on the internet. That

21:45

creates a little bit of pressure there. It opens that pin

21:47

right up. If you're running 20

21:49

degrees of super heat that way, try the nickel. That'll get

21:51

you. I may have done that as

21:53

a tech to try to save some product once

21:56

or twice, but I have pressurized it with nitrogen

21:58

just to see how that would work. And

22:00

it worked. It was very difficult to get

22:02

the nitrogen charge exactly where I needed it

22:04

for that super heat to be even stable.

22:06

It was massively overshooting or coming back down

22:08

with just the slightest adjustment. I cannot even

22:10

imagine trying to do that for real with

22:12

a case of that food in the middle

22:15

of a grocery store or something. That would

22:17

be a nice thing. How do you get

22:19

the nitrogen into the bulb? You got it.

22:21

You got it. You

22:23

kill a hole and then you add a singer? Oh

22:26

my gosh. This sounds fun. Would it

22:28

be better nitrogen or a little bit of the

22:31

– I mean, I know 400 blends make it

22:33

a little bit of trickier. But let's say you're

22:35

dealing with like an R22 or something, putting

22:37

a little charge of R22, liquid

22:39

R22 in there instead of nitrogen. I

22:43

feel like it would give you a little bit better of

22:45

a shot of working out. It's going to

22:47

take you back to how it was new if it was a 22 head. Just

22:51

remanufacturing that battery. Yeah. I mean, why even replace

22:54

it at that point? You just fixed it. Look,

22:58

you essentially made a new power head right there.

23:00

I don't know. I have to work on that.

23:03

The problem is that the bulb charge

23:05

is going into the system charge, and

23:07

that's why it quit working. That's

23:10

what we use out for the bulb. Interesting. So

23:12

that's what I – so hold that thought. That's why

23:15

they said yes. Sorry. Hold that thought because I

23:17

want to come back to that one. But Matthew, weighing

23:19

in on this, we always talk

23:21

about the thermostatic expansion valve as being like

23:23

a constant superheat valve. And we know that

23:25

it's not completely constant, but this goal is

23:28

to keep that superheat set within the minimum

23:30

stable superheat range for that particular case that

23:32

goes back to an old Jamie Kitchen reference.

23:34

And I want to talk about that as

23:37

well. But for this particular question, is

23:39

there ever a case where you would do this whole warm up

23:41

the bulb thing? So not necessarily the bulb. And I get what

23:43

they're getting at. They're trying to

23:45

see if I got 50 degrees of superheat. If I

23:47

add some heat, does it come down? That

23:49

would be the time that I would do that. And really

23:51

just holding it in my hand tends to be

23:54

a very quick check, right? I can see it move, or

23:56

it just doesn't. And if it doesn't, really

23:58

just taking it off the pipe. should within

24:00

refrigeration of course, because pipe's really cold. Just

24:02

taking it off. Pipe should cause that to

24:04

open up and start flooding like we were

24:06

talking about. You got to be careful how

24:08

far you go with that. So I don't

24:10

think I'd use hot water in the refrigeration

24:12

world just because if it is working, you're

24:14

definitely going to slam that thing wide open

24:17

and that's going to be dangerous. But

24:19

I do use hot water, don't get me

24:21

wrong, just not on the bulb. And that's

24:23

on the body of that compressor, or the

24:25

TXV. The old school problem we had with

24:27

our 22 mineral was

24:30

wax. We create a lot of wax, don't stop up that hole.

24:32

Still not a problem today. It's not wax,

24:35

it's a whole different chemical thing going on,

24:37

particularly with acidic, PO burnt, you start running

24:39

that stuff hot, maybe it's going to make

24:41

acid, but it's also going to burn. And

24:43

then you throw a little bit of moisture

24:46

in there from some poor practices, and you're

24:48

going to create a wax-like substance that loves

24:51

cold spots. What's the cold spot in the

24:53

whole system? That little tiny hole that

24:55

that pin is trying to regulate exactly. So

24:57

we do see them stop feeding for that

24:59

reason. It's not the bulb. If you drive

25:02

it open more, yeah, you'll get some refrigerant out

25:04

of there because the hole's plugged up. But as soon

25:06

as you let go, it's going to go back. Take

25:08

your hot water for it on the body of

25:11

that valve, that'll loosen that up just enough, make

25:13

it liquid enough so that pressure pushes it right

25:15

out of there. And then go change the liquid

25:17

line dryers because you've got a problem that's going

25:19

to stop up again. But that is one of

25:21

those diagnosis tools that we do use. Okay, good

25:23

stuff. So now I want you to go

25:25

through your list of the things that matter

25:27

in an expansion valve in order to prevent

25:29

issues, but also if you're running into some

25:31

challenges, things like mounting bulb straps, anything you

25:33

can think of that is your list. So

25:36

when I'm troubleshooting things that have gone

25:38

wrong, that's how I think of whether

25:42

we want to not do a couple of

25:44

them came to mind. The bulb clocking, as

25:46

we started talking about, is really not that

25:48

important. The goal here is really just to

25:50

be sure we're not sensing oil. That's one

25:52

of the problems I see. We're not sensing

25:54

oil well, or we're sensing the oil, we're

25:56

not sensing the liquid refrigerant that might be

25:58

in that suction line. So just

26:00

not six o'clock, please. That's the big one there. Another

26:03

thing that is really, really common

26:06

in refrigeration, service guy swaps out

26:08

at TXV that probably didn't need

26:10

to begin with. But those

26:12

key pieces we just started talking about

26:14

strapping that bulb well and it not

26:16

being corroded copper that we're strapping it

26:18

to. This goes for electronics

26:21

as well. Anytime we've got an

26:23

EV, an electronic expansion valve, that

26:25

sensor needs to go where the bulb would

26:27

be on a mechanical. And I see

26:29

them mounted just as poorly. That's one of

26:31

the biggest problems I've seen. The

26:34

other thing I see is guys, because

26:36

it's got an adjustable stem, guys like

26:38

to adjust it. And most of

26:40

the time it does not need adjusting. That is

26:42

not a problem. Just

26:45

missing those fundamental other requirements

26:47

that valve to work and

26:49

then verifying them, particularly in that

26:52

low-temperature refrigeration setting, we almost always

26:54

have some type of sub-cooing, mechanical

26:56

sub-cooing going on. We're bringing

26:59

that liquid way down 50 degrees. It's not

27:01

uncommon. So if I'm feeding that

27:03

thing with 97 degree liquid because it's July

27:05

and my mechanical sub-cooler is not working, that's

27:07

why my valve is not set right. I've

27:10

dumped a lot of efficiency out of that

27:12

liquid refrigerant. So a guy will go in

27:14

there and make temp, he'll adjust that TXV

27:16

and I pass up on the back. I

27:18

got this case running great. Two weeks later,

27:20

he finds out what's wrong with that sub-cooler.

27:23

He turns it back on and

27:25

wow, now we're flooding. We're popping valve plates

27:27

on compressors left and right. Why

27:29

is that? Because my valve just became twice the

27:31

size that it was. The

27:34

efficiency of the liquid refrigerant, missing

27:36

that, missing the pressure differential

27:38

in parallel rack. Sometimes

27:41

we've got a valve that regulates the

27:43

liquid pressure that's going to

27:45

the valve, see the expansion valve. If

27:48

that gets out of whack and I don't

27:50

have a good pressure differential from suction to

27:52

liquid, I'm going to lose efficiency in

27:54

that valve just like I make it with sub-cooler. I

27:56

got to remember to check that. I got to check

27:58

those two things and then of course. solid column.

28:00

Do I have a pure liquid coming to this

28:02

valve or do I have some paper in there?

28:05

I've seen a lot of guys twist on valves

28:07

not realizing they've got plenty of them triggering their

28:09

rack and they didn't realize they weren't getting it

28:12

to their valve. So they're trying to like a

28:14

high super heat. So they're opening that valve trying

28:16

to bring that super heat down with more vapor

28:18

and it just doesn't work. So those are some

28:20

of those key fundamental mistakes that I see regularly.

28:23

It's one of those things that's a common theme

28:25

when you're working in that field that you're just

28:27

going to run into. One thing

28:29

that you mentioned that I think is always worth

28:31

mentioning is this idea of the pressure drop across

28:33

the valve. And this is where you see one

28:36

of the advantages of electronic valves, but

28:38

also you hear people

28:40

talk about balance port design. And that's

28:43

really what that is. Understanding what the difference is,

28:45

is not that big of a deal, but just

28:48

understand that that balance port design is

28:50

there so that way it will still

28:52

operate stable under a

28:54

lower pressure drop differential. At least that's my

28:56

understanding. Is that your understanding or anybody care

28:58

to add to that? Yeah, I'd

29:00

say it's not going to do it

29:03

a hundred percent if you've got a

29:05

giant change. And that's why we have

29:07

some customers that are putting that pressure

29:09

regulator to give a regular pressure to

29:11

those TXVs year round, even though they're

29:13

balanced port. Because you think about

29:15

it, our extremes, we may lose a convincing fan

29:17

motor and be running 275, 300

29:21

discharge in the middle of the summer.

29:23

And then my whole back valve's catching

29:25

everything at 135. That's a dramatic change

29:27

in that pressure differential that you were

29:29

just talking about. We know one of

29:31

the factors In sizing,

29:33

the valve is differential pressure. So That

29:35

means that that lower pressure, my valve

29:37

is less efficient, that higher pressure is

29:39

more efficient. Now You add mechanical sub-coil,

29:41

so that I got consistent liquid temp..

29:44

So When my pressure went up, I

29:46

did not increase my liquid pressure, which

29:48

offsets that in commercial air conditioning.. You

29:50

Really don't have to worry about that

29:52

all the time.. Because When my discharge

29:54

pressure goes through the roof, so does

29:56

my liquid temp.. So One gains efficiency

29:58

in the valve, one... And

30:00

in a snake the house that ever happened

30:03

when we're controlling one of those two were

30:05

excitedly. we're gonna see this was his concerns.

30:07

So much so that some of the folks in

30:09

the North actually have to set their yes means

30:12

or manual just least twice a year from the

30:14

seasons. Were. Fortunate down there in

30:16

Florida, we don't have that dramatically two

30:18

percent, but it does impact supremes, And

30:20

that's also the reasons why we're not

30:22

really trying to target that. Exact

30:24

superheated temperature is arrange a to tenth

30:27

as I mean said and nine amazon

30:29

the summer pointless of that thing. Route

30:31

centers probably a good stuff. Can I

30:33

add to that? reflects Jaeger had about.

30:35

Just like you said, Csv. A lot

30:38

of people figured I better. These.

30:40

Bags or devices on were saying an

30:42

earlier were talked about the other variables

30:44

to and so on that. This.

30:46

Valve is going to work properly before

30:48

you go into just about finally have

30:50

a platform to where I can say

30:52

this a lot so i brought some

30:54

seven sell it at their are now

30:56

was a to show a people listening.

30:59

Why? You don't want to go to

31:01

suggest valves without checking your liquids and

31:03

like that the center a pianist are

31:05

cooler or any of those other variables

31:07

that we are talking about. His fear

31:09

is these are just a few. I've

31:12

got a ton of them. These are

31:14

stripped out the Xp stems. From.

31:16

People over adjusting them at times

31:18

and what in the packaging is

31:20

and here. Is. Actually, I have

31:22

one already ripped apart hear? That is

31:25

your adjustment, stem cell, your service or

31:27

to go here. This will apply some

31:29

pressure to the expansion of. If

31:31

you. Start. Turning those too much,

31:33

you're going to strip that mechanism out. and it

31:36

is once you stay. In. Whatever

31:38

position. Foolish. That

31:40

you should out. So if you ran at all

31:42

the way and and you run at all the

31:44

way and you much you're never gonna get that

31:46

thing opened up and vice versa. And you're super

31:49

he time you're open enough that same as much

31:51

as possible you might end up getting it to

31:53

be. But. Now you're in

31:55

a flutter. Same thing with these:

31:57

A bucket for a dirty. A

32:00

third down streets. Every single

32:02

one of these dirty. Ivan. How

32:04

Paolo bucket forces dirty txt such as he

32:07

can receive in this the whenever I get

32:09

a chance Matthew runs be wild so don't

32:11

have a chance right now. but I just

32:13

played organized as we swap of Alive and

32:16

or put a clean what it takes thirty

32:18

one out that way it has little bit

32:20

more efficient by. Would. You do feel

32:22

the need to adjust. Just. Make sure

32:25

that you have all of the information that you

32:27

need. Before. Saying okay. I

32:29

just need to a justice and heritage.

32:32

They make sure your airflows give. Don't

32:34

try to close down your says thou

32:36

when your filter had the homeowners cap

32:38

on it and. Look. For restrictions

32:40

that can, we talk about that one

32:42

airflow and select that's the Etti post

32:44

something online as the first thing somebody

32:47

says with tic Airflow. The. Our panelists

32:49

went over and joe, you wanna take a stab at this

32:51

or matthew. Yeah typically.

32:53

The Tx bees meter radically call hunting

32:56

was just means it's in this weird

32:58

position where it opens a little but

33:00

as too much and the closes a

33:02

little but it's too much. So.

33:05

That would probably happen when you have like

33:07

a big five ten bow. Maybe.

33:09

It's on like a three and a half because

33:11

most the valves in my. Stuff I

33:14

work on the have to add some

33:16

like one to three or three that

33:18

buys and that's a broad range and

33:20

maybe them valve as a little beyond

33:22

where it can really. Move. A

33:24

little bit. And then not

33:26

flooded and then shut a little bit and

33:28

not. Starbucks. Said.

33:31

Make sense. Does to media. that

33:34

i'd agree that i do one point

33:36

out though there is a little bit

33:38

of difference here between normal operation in

33:41

a low low edition and in hunting

33:43

like ecosoc that quitting really occurs when

33:45

the valves oversize and maybe oversized maybe

33:47

such perfectly for the system but it

33:49

is my seat heat and there's or

33:52

blower problem you can filter dirty or

33:54

something like that with the your upbringing

33:56

the heat of the house into that

33:58

operator lesson of make that five ton

34:01

valve, only see three tons where it works. So

34:03

it's going to be oversized and you're going to

34:05

get that. But one of those things that is

34:07

normal, and we call this in the refrigeration side,

34:09

the swing, and this is when

34:11

I'm measuring my super. I've got my

34:13

temperature probe right there on the line

34:15

and I'm seeing this thing go up

34:18

and it hangs out for a minute and

34:21

then it starts falling really fast and it

34:23

drops and it gets down to a temperature

34:25

and then sits there for just a few

34:27

minutes and then she starts back up again.

34:29

I got the cycle going on and the

34:31

way to know the difference is that it's

34:33

really regular when this is happening. This is

34:36

really controlled. You know what it's going to

34:38

do next. The spot that it

34:40

hits the bottom is always going to be

34:42

the same spot, same temperature, and

34:44

that's going to take a while. It's going to take 15 minutes or

34:46

so, 10, 15 minutes to get

34:48

this full swing going on and that's

34:50

not hunting. That's normal operation that is

34:52

similar to hunting in that I'm in

34:54

a low load. My case is

34:57

probably very close to being at

34:59

temp. My product is also cooled

35:01

down. That expansion valve is sized to pull

35:03

that thing down from deep frost four times

35:05

a day or six or 12 nowadays. So

35:07

it's a little bit oversized when I'm really

35:09

happy when my cases are at good test.

35:12

So when we go to set the superheat, the

35:14

question is if this thing is swinging 12, 15

35:17

degrees, what do I call my superheat?

35:20

The top, middle, the bottom, what is that? And

35:22

a lot of guys get really confused about

35:24

that. So I'd like to take just a

35:26

moment and say that if you're dealing with

35:28

that cyclic for minutes, it's nice and smooth

35:30

and does it every time. Stops at the

35:32

same spot at the bottom. That's

35:34

just because your evaporator is very, very

35:37

big. And by the time that valve

35:39

opens, it's going to take it a while for all that

35:41

heat to transfer and your printer to come out the other

35:43

end. That's all that that is. And the

35:45

more heat I have, the faster that happens. So when

35:47

I get down to temp, it just takes a little

35:49

bit. When I've got that going on and I'm measuring

35:52

superheat, if I say I want six degrees of superheat,

35:54

I'm measuring that temperature at the bottom

35:57

of that swing, right where it

35:59

turns around. not the average, not the

36:01

top. Just putting that out there. That's another one

36:03

of those big things that I see guys aren't

36:05

real comfortable with it, doing a lot of math

36:07

and coming up with some averages, which can work

36:09

sometimes in some conditions and in others if it's

36:12

what. Yeah, you're worried about the flooding. That's the

36:14

really bad thing to have happen. I

36:16

wanted to also just mention this minimum

36:18

stable superheat thing. If you are getting

36:20

hunting, like true hunting, sometimes the easiest

36:22

way to solve that is just to

36:24

not derive that superheat so low. So

36:27

you can drive this superheat low enough that

36:29

it becomes unstable and you start to get

36:32

hunting there as well. I wanted to now

36:34

send this over back to Joe and I

36:36

wanna bring up this slide here. So Joe,

36:39

two questions here. The one is,

36:41

is it important whether the bulb is

36:44

on the coil side or the compressor

36:46

side of the external equalizer? Does that

36:48

matter? So before or after the external

36:50

equalizer in the suction line? That's one

36:52

question, okay? And the next one is,

36:56

what happens when your external equalizer

36:58

blocks? What happens when

37:00

maybe solder blocks it or maybe it

37:02

was connected and they didn't use a

37:04

core depressor on a Schrader or something,

37:06

so it's completely blocked? Those are your

37:08

two. And that first one, I'm talking

37:10

about politics just a little bit. I'm

37:13

just letting you know, you are in danger. If you

37:15

didn't know, you're gonna make a decision one

37:17

way or the other here and some people are not gonna

37:19

like it. Right. Joe already says

37:21

unpopular things online all the time. Yeah, that

37:23

should be the same. Those people don't like

37:25

me. What's one more here? Oh, Joe for

37:28

president. He

37:30

speaks his mind. That's what I like about Joe. Cheer

37:33

for president, 24. That's right,

37:35

yeah. So the

37:37

textbooks would say you want the

37:39

equalizer downstream from the bulb. And

37:43

yes, I have seen where

37:45

things happen. Like that equalizer

37:48

line is freezing. I mean, it's

37:50

feeding a little bit of refrigerant

37:53

down that Equalizer line, but

37:55

that's like a broken valve in my

37:57

opinion. That's a problem. That's a problem.

38:00

That was certainly affected if that

38:02

was happening right upstream from your

38:04

ball on a properly operating valve,

38:06

I don't really. That. Equal

38:08

letter line because it was need to

38:10

be insulated in the stuff we work

38:12

on this in the case of an

38:15

externally mounted bow that as that line

38:17

was can be feelings like a Lola

38:19

Kepler to it would sweat and cause

38:22

rusted out. Dream. Panzer.

38:24

He just tell that it's been sweating.

38:27

It's allies and I typically don't see

38:29

that, so I don't stress that a

38:31

lot myself. From. That standpoint.

38:34

And. That because there's no flow, you

38:36

don't have actual floaters. equalizers is the

38:38

constant pressure. use mine during the pressure.

38:41

right? There probably is a little bit

38:43

of flow and I'll lead me to my

38:45

next. Topic. There.

38:48

But. It's not enough. To. Be.

38:51

Like. Effect. Driving. The both

38:53

closed or anything like that. So yeah, there's

38:55

not going to be a lot of love

38:57

and it also the funny thing is is

38:59

it has nothing to do. With.

39:01

The system equalizing on this are cycle.

39:04

Or nothing to do with it. Yeah. That

39:06

brings us national my man. Yeah.

39:08

And that brings us to Eric Kaiser's which

39:11

of course he's is Eric says are geniuses

39:13

or right? So the reference line is what

39:15

he's proposing is should be called and not

39:17

the equalizer line. I like that. I would

39:20

probably clear up a lot of confusion that

39:22

people have like a reference line. Yeah, Sorry,

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dash wipes. Before

40:44

you move on to the next thing, though, Joe, I wanna

40:46

quickly... Corey or Matthew, do either of you have anything that

40:48

you wanna add to that... external

40:50

equalizer before or after the bulb? I guess basically

40:53

the question is, do you think it matters? Do you

40:55

have a preference? And we already established that the textbooks

40:57

say downstream of the bulb. So my school of thought

40:59

on this is, and sorry, I'm not gonna take a

41:01

stand. I'm just gonna give you both opinions. Why?

41:05

If you move that towards the evaporator, if it's

41:07

on the evaporator side of that line, then

41:10

you're measuring pure superheat of that evaporator. If

41:12

the valve starts to leak liquid refrigerant, and

41:14

they do, but they're not supposed to, but they do,

41:16

and that's one of the reasons we change it, right?

41:19

In the meantime, if you're towards the

41:22

evaporator side, like this is drawn, you're

41:24

gonna measure that perfect superheat in the

41:26

evaporator, and your priority is the load.

41:28

You're gonna get the most efficient system, and you're

41:30

gonna cool whatever you need to cool well. That's

41:33

the point in putting it on that side. The

41:36

downside is, if that line really starts

41:38

leaking a lot of liquid, you're

41:40

gonna flood, because now that equalizer line

41:43

is passing liquid refrigerant that's not really

41:45

intended to, and it's going into

41:47

the suction line. So yeah, you got some liquid going back

41:49

to your compressor. So

41:51

if you wanted to design the system to protect the compressor

41:54

over the cost of refrigerating my product

41:56

or cooling my house or whatever, I'm gonna put

41:59

the valve on the other side. And that's going

42:01

to sense that, and it's going to starve my

42:03

evaporator so that I'm not flooding my system. So

42:05

the question is which is more important, and then

42:07

you could evolve there based on that. I

42:10

like it. All right, now I like both perspectives, though. That's

42:12

great. So back to you, Joe. What

42:14

happens when an external equalizer gets blocked? It

42:17

will basically close and

42:19

never open again, short answer to

42:22

that. So if you have

42:24

a system

42:28

that will not present itself

42:30

that way at first, which is

42:32

always an interesting theory,

42:35

that if you connect the

42:37

line, and let's say that you

42:39

put it on a port with a Schrader

42:41

core and your new valve does not have

42:43

a Schrader core depressor, then that

42:46

line will actually have zero pressure

42:48

in it at first. And

42:50

you'll fire the unit off and it'll flood.

42:53

And you may or may not realize,

42:57

perhaps, maybe younger tech or something, beer

43:00

can cold, sexual pressure's up,

43:02

good to go. They leave the

43:05

house. Guess what? That valve

43:09

will leak a little bit of

43:11

refrigerant into that line from

43:13

the valve side of it. So

43:15

as the pressure climbs into that

43:17

port, now instead of

43:19

seeing suction pressure, it's seeing like the

43:22

off cycle or even the liquid, maybe

43:24

even higher than the off cycle pressure, which

43:27

will be slamming the

43:29

valve closed, thinking you have way too high

43:31

suction pressure. So then

43:33

you'll get a call, maybe the

43:35

next day, maybe even a day after, and

43:38

you'll think you're brand new to TXV, you

43:40

got a bad batch of them and type

43:42

of thing. And that can probably go for

43:44

maybe getting a little too much solder in

43:46

one if it's a one

43:49

that you solder on. Or I

43:51

don't personally see a reason why

43:53

there should be a Schrader core

43:56

in the line with a depressor because

43:58

you're not going to get it. going to

44:00

replace the valve without pumping

44:03

the system down or evacuating it. So

44:05

why is that really important? I'm not sure

44:07

I can't answer that, but I

44:09

have seen where the depressor

44:12

portion in that flare

44:15

fitting almost crushes down

44:17

or closes off the

44:19

access port, maybe because it had a

44:22

over tightened flare cap on it and

44:24

it's mushroomed down a little, but I've

44:26

actually seen where that can almost close

44:28

off the entire port. When you wrench

44:30

down on your new valve, even though

44:33

you did take the Schrader out or

44:35

there was no Schrader in that access port,

44:38

then you wrench it down and that

44:40

little brass depressor almost wedges

44:43

itself into that access port.

44:45

That's pretty rare, but that's why I like bringing you on

44:47

there. Cause you were the king of the edge case. Joe

44:49

was like, this one time I had a,

44:52

you know, someone out there is probably like,

44:55

yeah, I took it off and that brass

44:57

thing was like crammed down in the access

44:59

fitting. And that was the problem. So personally

45:01

I just rip them out. I take

45:03

them out of that. So just to clarify

45:05

what you're saying, there are some cases in

45:08

air conditioning applications where where you connect your

45:10

sternum and glizer has a stub

45:12

on it. And it has a Schrader

45:14

inside that port. And what you're saying

45:16

is you pull that out so that way you're

45:18

not risking any issues there, whether you're a Schrader

45:20

and the depressor out of the, and the depressor

45:22

right out of the flare connection. I

45:24

want to hammer this home because this is really interesting

45:27

and this is one of these things, or at least

45:29

it's interesting to me. And if it's not interesting to

45:31

you, then why are you watching this live stream? Why

45:33

are you sitting here in Valentine's day watching this? If

45:35

this isn't interesting to you, are you sick? The answer

45:37

is probably yes, but I'd address it. So when

45:39

I was a cocky young instructor, I would tell

45:41

people, Hey, if your external equalizer

45:44

plugs, then that is going to

45:46

cause the valve to go wide open because

45:48

it shows it right here, right on this

45:50

diagram. The external equalizer is the closing force.

45:52

So you lose your closing force. The valve

45:54

goes wide open, but it was

45:56

guys like Joe and others who showed me the

45:59

truth, which is. that like you said

46:01

because this valve does leak a little bit

46:03

from the valve side or it tends to,

46:05

it will pressurize from the valve side. And

46:07

especially in the off cycle, it's going to

46:09

pressurize with higher pressure. And so it's going

46:11

to cause the valve to just slam completely

46:13

shut. So basically, most problems that happen with

46:15

valves that are catastrophic are valve goes completely

46:17

slam shut, whether you lose your bulb pressure,

46:19

whether you have a blocked external equalizer line,

46:21

or whether there's some sort of internal problem

46:23

with the valve. Those are the most common

46:26

issues that we see, for example, the air

46:28

conditioning side. But on the other side, it's

46:30

when you run too low of superheat. And

46:32

that's things like Matthew's talking about where you

46:34

have oversized valves or a valve operating oversized

46:37

because of load conditions, or you have improper

46:39

settings, things like that. I've talked through a

46:41

bunch of really important things here. Selecting the

46:43

right valve is huge, not adjusting the valve

46:45

unless you absolutely need to and then adjusting

46:47

it properly, adjusting to a stable

46:49

superheat, not to something that's going to be

46:51

erratic, flowing nitrogen while brazing. So

46:54

first you purge with nitrogen, then you flow

46:56

nitrogen while brazing. That was one of the

46:58

questions. But I want to come back to the question

47:00

of strapping. And I want to go back to you, Corey. In

47:02

terms of the straps that you use, does it need

47:04

to be copper? Somebody said this and there, does it

47:06

need to be a copper strap? Could it be a

47:08

stainless steel strap? What are some of the really

47:11

big things you need to watch for in terms of

47:13

the strap? Would you like my answer? Would you like the

47:15

manufacturer's answer? Well, you can

47:17

give both do it the Matthew Taylor way,

47:19

where you just you just Okay, Matthew Taylor.

47:21

So Matthew Taylor, that's going to be the

47:23

copper straps supplied with the unit or what

47:25

we use in refrigeration build valves. I can

47:28

stock a multitude of different refrigerant

47:31

power heads, cartridges, and literally on

47:33

site within less than a minute,

47:36

an expansion valve, and every power

47:38

head I'm assuming it I haven't bought

47:41

a regular TXV in a long time,

47:43

but I'm assuming they also come with

47:45

it. But every power head that we

47:47

buy, it comes with the manufacturer's copper

47:49

straps. I will tell you this, I can

47:51

never put those on. I don't know what it is.

47:53

So if I'm installing one new, it never really works

47:55

right. The copper straps or brass or whatever

47:57

they are, are going to be your best bet. because

48:00

the heat transfer is the same material

48:02

as the bulb and the suction pipe.

48:05

I personally like black zip ties. No kidding.

48:07

We were about to just pull out the

48:09

torches and pitch works. I know.

48:11

I was gonna run with that for a little

48:14

bit and just go on this whole like feel

48:16

about. Yeah. I've seen people use hose clamps. I've

48:18

used hose clamps a lot actually.

48:20

People are gonna also be like,

48:22

oh, dissimilar metals. Honestly, it doesn't

48:25

matter. But obviously, always try to use those

48:28

copper straps. That is your best bet. As

48:30

long as you don't use zip ties, use

48:33

something that is going to conduct the heat or

48:35

at the very least keep that bulb secure

48:37

over varying conditions.

48:40

Because here's the thing like with using zip

48:42

ties or other forms of

48:44

strapping is that it might

48:46

be tight when you first put it on

48:49

and you're like, oh, that's not gonna go anywhere. But

48:51

especially in refrigeration where you have defrost

48:55

and you have cases getting cold, getting

48:58

warm, that thermal expansion, it's

49:00

going to loosen those zip ties. It's

49:02

gonna start deteriorating them

49:04

and air conditioning, same thing. And

49:06

eventually it will get loose. And then you're gonna have

49:08

those problems where you're getting

49:11

service calls because, oh, the

49:13

bulb wasn't strapped. Okay. Well,

49:15

why wasn't bulb strapped? Well, it's because there's

49:17

zip ties on there. There's tape and that tape just came

49:19

off. But me personally, long story

49:21

short, copper straps or hose

49:23

clamps. I want Matthew to weigh in on

49:26

this. But also I just want to add,

49:28

from my perspective, the biggest thing if you're

49:30

installing a valve is just getting it on

49:32

a straight piece of copper. Some of the

49:34

dumbest things I see is where people just

49:36

have it like on a joint or a

49:39

otter or something dumb like that cleaning it on.

49:41

Yeah, getting it on now I do know a

49:43

hose clamp, so a lot of people have said

49:45

you can over tighten a hose clamp. That's actually

49:48

one of the dangers. And my top

49:50

tip for the copper strap, okay, is when

49:53

you get it together, you just get it so

49:55

you can just get the thread in like people

49:57

always do it. You can I've done

49:59

like a thousand. I have tried,

50:01

I practiced, it doesn't

50:04

ever work. It's either

50:06

really loose or I just can't line it up and

50:09

then I get frustrated with it. I'll take some,

50:11

sometime like they've already been off and ripping out.

50:13

Like I'll take those clamps so that way I

50:15

can just, it's already molded perfectly to the pipe

50:18

and you know, smash them up

50:20

and yeah, why not? Matthew, your

50:22

thoughts on the strap type, copper,

50:24

stainless steel. I wish I

50:26

had something controversial to throw out here. Really?

50:28

Yeah, I'm a copper strap guy myself. And

50:30

one of the advantages of that are, as

50:33

Corey said, I've seen a million hose clamps,

50:35

right? What's wrong with that? It's

50:37

nearly impossible to over tighten the copper.

50:39

Like you've seen Corey, it's difficult to

50:41

get all that going right

50:44

away. You're not going to over tighten it because

50:46

it recesses itself into the strap a little bit

50:48

and you start to lose your wrench won't grab

50:50

it anymore. It's off. And I don't

50:52

think there's any question that transfers heat better, but really

50:54

we're trying to pick that up from the bulb

50:57

to the pipe where they actually touch that's key

50:59

to transferring that heat. We're depending on our strap

51:01

to help that we got something wrong. So the

51:03

hose clamp is fine. That's going to hold it

51:06

nice and tight on that pipe. I don't see

51:08

an issue with that. Been doing

51:10

this a long time. I've seen some corrosion form

51:12

on that tight thing over 20, 25 years. And

51:15

that's all it is. We want to go to

51:17

the outside. Warranty period is gone. A problem. Right.

51:22

So I wouldn't endorse that in writing

51:24

anywhere until anybody, that's what you should be

51:26

doing, we should be using the copper. That's

51:28

what we got. Yeah. A friend of mine. Or

51:30

if you're troubleshooting something, that's not the problem. If

51:32

that's how it's attached, you got

51:34

something else going on. I wanted to

51:36

quickly, so especially Joe or Matthew,

51:38

you see here on the

51:40

right where it shows that you should have the tails

51:43

pointing up when you're on a horizontal piece of pipe

51:45

or not a vertical piece of pipe. Why

51:47

does that matter? And does it matter? I've never

51:50

really heard a great explanation on this. Joe,

51:52

if you don't mind, I've got this one. You

51:54

can buy different types of heads. We're talking about

51:57

power. That's we're talking about a thermal element. This

51:59

is the head. that has the bulb

52:01

attached to it and has a particular

52:03

type of refrigerant inside of it. There

52:05

are different versions of that. The

52:07

refrigerant that is inside of it also varies

52:09

a little bit. So you see your temperature

52:11

scale that'll show that it's at 60 degrees,

52:14

it's going to do this, at 30 degrees,

52:16

it's going to do this. All those things.

52:18

If we look at that chart, you'll notice

52:20

on the side, it's also going to tell

52:22

you whether that is a liquid charged bulb

52:25

or a vapor charged bulb. And what they mean by

52:27

that is there's a little bit of liquid vapor to

52:30

saturation in either case.

52:32

But if it's a liquid charged bulb,

52:34

the majority of the bulb is actually

52:36

full of liquid refrigerant and there's a

52:38

little bit of space for the

52:40

vapor. If it's a vapor charged bulb, just an

52:42

office and there's just a small amount of liquid.

52:45

So the challenge is, if I've got one

52:47

of those vapor bulbs and I turn the

52:49

thing upside down, I'm using all my liquid

52:51

to fill that cap tube instead of leaving

52:53

it in the bulb to expand because I

52:56

don't have enough. So if I've got

52:58

a liquid charged bulb, well, it probably doesn't matter.

53:00

I probably have enough liquid either way. But if

53:02

I've got a vapor charged bulb, I won't and

53:04

it won't have the liquid in actual

53:06

part that it needs. So it won't sense

53:09

properly. Wow, that was a surprisingly good

53:11

answer. I should

53:13

just be learning from Matthew. Cool. So

53:15

I'm going to quickly answer this question,

53:17

hard shut off TXVs, otherwise known as

53:19

non bleed TXVs. You can either way

53:21

you want to describe it. Sometimes they'll

53:23

say HSO hard shut off or non

53:25

bleed. And all that means is

53:27

because I think a lot of people get really

53:29

confused about what hard shut off means. And so

53:31

I want to actually go to this. Yeah, this

53:34

one right here. So in the case of a

53:36

valve that is just doesn't have a bleed port

53:38

in it, and if it's sealed internally, it's automatically

53:40

going to be hard shut off. And the reason

53:43

is, is because what's happening? Well,

53:45

when the system goes off, what

53:47

is your superheat? This is the easiest way

53:49

that I can think to explain this. When

53:51

your system is off, your superheat is zero.

53:54

So what should your valve be trying to do when

53:56

your superheat is zero, it should

53:58

be trying to slam shut and again, It's just these

54:00

balance of powers thing that we're talking about here. So

54:02

my easy description about a hard shut off CXV

54:05

is that's the way that CXV

54:07

would naturally be unless there

54:09

is some bleed function in the valve. And

54:12

the only real benefit of that is, and that

54:14

can be a good thing or a bad thing.

54:16

The benefit is, is that in systems that don't

54:19

have other forms of mitigation, it can help prevent

54:21

flood back, especially flooded start. The

54:23

downside is, is that now your compressor is turned under

54:25

more load. And so there's a trade off. You get

54:27

smaller systems. A lot of times they'll have bleed valves

54:29

in them just so that way the compressor doesn't have

54:31

to start under as much load. Anyone

54:34

have anything to add to that? Did I say

54:36

something stupid or wrong or anything that I missed

54:38

there? No, but it's very important to know what

54:40

kind of compressor you have in this instance, because

54:44

if you have an older unit and you

54:46

have reciprocating compressor and you

54:48

have an intermittent complaint of it's not cooling,

54:51

there's your problem and it may go undiagnosed for

54:53

years. Same with rotary compressors.

54:55

I think rotary compressors are coming back

54:58

a little bit and some

55:00

smaller ton of units and

55:03

they don't start up so well under differential pressures

55:05

like that either. So you will need to check

55:07

and make sure that if it's an old reciprocating

55:10

compressor, you don't see a lot of those anymore,

55:12

but every once in a while you'll come

55:14

across one where maybe someone's put

55:16

a new air handler with an older outdoor unit

55:19

and it's going to have to have a hard start and

55:21

a good one too. That can get it going. A

55:24

real kicker. Eric, once again, is

55:26

asking a question that he already knows the answer

55:28

to, and this is one of my

55:30

favorite topics. When a system is under vacuum or

55:32

has no charge in it, then a hard shut

55:35

off valve does not hard shut off because

55:37

now you have no external equalizer

55:39

pressure. And remember the external equalizer

55:41

is that closing force. So without that closing force,

55:43

that valve goes wide open. So when you're pulling

55:45

a vacuum or when the system has no

55:47

charge in it whatsoever, then it is not hard shut off. And

55:50

that's what comes up. A lot of people get worried with a

55:52

hard shut off valve that you can't pull a vacuum through it

55:54

and you most certainly can. One

55:56

of my best examples is when you're pressurizing a system and

55:59

you're putting nitrous. and you're putting it, say

56:01

you're putting it in the liquid side, that was the way that

56:03

I was trying to do it. So you put it in the

56:05

liquid side, you watch suction coming up, and all of a sudden,

56:07

suction just stops, and liquid keeps rising on you. And that's when

56:10

you hit that balance point where now that valve has slammed shut

56:12

on you. I think we've all probably seen that one point in

56:14

time or another. Plugs stuck in the

56:16

pipe? That

56:18

could also be it. I'm not going to say

56:20

that this did or didn't happen, but it's possible

56:22

that the first time we did a brand new

56:24

walk-in for a grocery store, we left one of

56:27

the plugs, and it made its way back to

56:29

the... It's always a nice surprise. It

56:31

is. It's a fun little gummy surprise.

56:34

Oh, yeah. So we are overtime already, guys. I

56:36

want to just wrap it up by just giving a quick

56:38

summary, and then we'll wrap it up. But you need to

56:40

make sure that you have liquid going to your valve, which

56:43

means that you have to make sure you have sub-cool. That

56:45

would be things like ensuring that you don't have restrictions

56:47

or you don't have plug dryers. That's

56:50

the very first thing you have to do. You want

56:52

to make sure that your bulb is well-mounted.

56:54

The positioning on the clock position isn't as

56:56

big of a deal as long as it

56:58

isn't sitting right on the bottom, as what

57:00

we've talked about. When you're in air conditioning

57:02

applications, insulating the bulb can make a big

57:04

difference. If you're in a refrigerated case, not as

57:06

much. Don't adjust the valve unless you

57:08

need to, but also don't be afraid to adjust

57:10

it when you do need to once you've established

57:12

that everything else is functioning properly. Plugged

57:15

external equalizer will actually result in

57:17

the valve going fully closed eventually,

57:20

so that's just the adjustment and thinking there.

57:23

The size of the valve, selecting the correct valve,

57:25

sizing of the valve, is it hardshot off or

57:27

does it have a bleed function in it? Those

57:30

are all really important. So selecting the correct valve is

57:32

always really critical. Do not try

57:34

to adjust the valve, but it's not adjustable. Otherwise, you

57:36

will have a big issue. Also, make sure to put

57:38

it in the proper direction or orientation. I'll

57:41

give it back to Matthew here. Anything else

57:43

that I missed or anything closing that maybe we didn't

57:45

talk about? I can go

57:47

on for about two hours. We got that? No, probably not.

57:52

On the recap, I just want to also

57:54

talk about the airflow. Obviously, we've got to

57:56

have a good airflow. In the refrigeration side,

57:58

we should be setting our... Super right

58:00

after deep frost if we're walking up to

58:02

this case. It's four hours into its cycle

58:05

You shouldn't be touching it. So just another

58:07

one of those little triggers in the mind

58:09

would make sure I've got heat I've got

58:11

load before I just also I

58:14

want to have a stable suction pressure This

58:16

is another one if it's falling it better be

58:18

falling really slow So if my

58:20

suction pressure is moving around that's half

58:22

my calculation for super heat My

58:25

valve doesn't casually instantly my tools

58:27

probably don't either and I'm

58:29

definitely gonna be wrong So I want to have

58:31

a nice stable suction. That means in refrigeration. I've

58:34

got an electronic EPR I have to force it

58:36

I have to force it so it doesn't move

58:38

and holds that suction pressure right where I need

58:40

it to be before I started Just good

58:43

stuff. Like Matthew said we could go on a

58:45

long time. This is a great group Thank you

58:47

guys so much for taking the time everybody who?

58:50

Neglected their most important relationships in their lives to

58:52

be here and watch this All I

58:54

have to say is you need counseling, but better.

58:56

That's a great place to go for that. Anyway

59:02

Thank you Big

59:07

thanks to all these guys in ladies who make these

59:09

podcasts possible. We have a big

59:11

team behind the scenes We have Adam and

59:13

Matt who consistently show up and help us

59:15

Roman many others Possible

59:17

and then our guests who are so willing to do it

59:20

so big thanks and For any of

59:22

you who are ever interested in doing this kind of thing.

59:24

It's really easy You can always just shoot me an email

59:26

Brian be our why and at HVCR school comm if you'd

59:28

like to be on the live Stream and you have a

59:30

topic suggestion We also have our

59:32

new speak pipe where you can go

59:34

on and ask a question and we're

59:36

happy to answer We recently sent that

59:38

link out via our tech tip emails

59:40

and we'll be sending that out more often Anyway

59:43

regardless Thanks for listening. So

59:46

I bought my daughter a handbag from

59:48

Iraq. She said thanks for

59:50

the bag dad Boy

59:55

thanks for listening. We'll talk to you next

59:57

time on the HVAC school podcast Thanks

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