The "king" or service valve explained

[@84DavidM777]

11 year old video still serving the community! Thank you kind sir!

[@vernroach3413]

I often watch this gent on different parts of different systems, sometimes for refreshers and sometimes I outright learn different ways to do service and then share it when I instruct my students, as a part time instructor...Always clear, simple and easy to understand...The man has a gift, being able to share what he knows, so others can under stand it too...My thanks to the gent once again.

[@grayfurnaceman]

Thanks for the support. GFM

[@lex6794]

I am a Maintenance Mechanic / Boiler Operator by Trade, here in New Jersey. My Company wanted me to start doing HVACR work. So I am in HVACR School. I always watch your videos, you explain things great, and I understand easy. Please keep on doing your HVACR videos. Thank you very much!

[@grayfurnaceman]

Thanks for the support. GFM

[@TomJones-uf5sl]

This is an excellent explanation of the HVAC service valve.

[@lance16O1]

I'm currently in a debate with someone about whether the packing nut even needs to be touched when operating these valves. I was taught to have it loose when operating it, and tight before you walk away from it. Thank you for confirming what I was taught.

[@user-dm8kz8ul8h]

Who’s at work right now learning on the spot and playing it off?

[@Progress24.7]

Lol 😅

[@scottdowney4318]

I have this style on my boat cruisair heat pump. For the opening and closing, I use a tap handle holder, it screws down tight on the square stem. You may find people have used vice grips and mangled those valve stems, so a tap handle you can get a good grip onto the square valve. And works well. So if you have the tap handle you wont need that special wrench.

[@nisw1918]

Thanks I needed to figure out how these things work .

[@Sc19869]

How would it be positioned if you would be checking the pressures. Thank you for the video sir.

[@grayfurnaceman]

Backseated to connect the gauge set, them cracked to midseated. Reverse to remove gauge set. GFM

[@Rattletrap2]

Nice explanation of the valve operation. In this case, this is a "suction" service valve. A "King" valve is similar in function, but is located at the outlet of a receiver, and can be used as a liquid charging valve. The "queen" valve is seldom seen these days on smaller commercial systems, but would be on the inlet to the receiver for isolation. It is important to "crack" the packing loose on your valve before turning the stem, so as not to damage the packing gland. It has to be snugged up again when done.

[@grayfurnaceman]

Good info. Thanks GFM

[@StupidPeasant]

+Rattletrap2 If the valve leaks at the stem packing; Many folks don't know when this type of valve (with a packing nut) is back seated, you can unscrew the packing nut all the way and very little refrigerant will leak even when the unit is running. Then you can repack the packing by wrapping some teflon tape around the stem a few times and tighten the nut back down that squishes the teflon tape down into the packing area. This will stop the leaking. Do not try to stop the leaking by just putting thread goop on the cap. Please do not use channel-locks on the stem and damage it. Use only a flat type wrench. Also, loosen the nut and/or a drop of oil on it to make it easy to turn. Then retighten. If there is no packing nut and it leaks; you must replace the valve.

[@grayfurnaceman]

Can't argue with that. GFM

[@smondal1463]

Thanks for the valuable information.

[@sillypuddystl2907]

Wonderfully explained. Thank you

[@ronie1337]

Thanks for the info!

[@braydon44884]

Thank you this helps so much!!

[@JP-sd2cw]

I always wondered, how do you loosen the packing to adjust the valve with the compressor under a vacuum? Won’t it suck in air through the packing, that would ruin the vacuum and introduce moisture.

[@grayfurnaceman]

Why loosen the packing? The valve will move with the packing tight. GFM

[@JP-sd2cw]

@@grayfurnaceman If you do not loosen the packing and you adjust the stem you will damage the packing gland and cause the valve to leak. That's why people change packings.

[@customsausage1014]

thank you for the clear explanation

[@ap9012]

You said the stem has some packing, and it is possible to change it if leaks? But how do we remove that pack, i cant remove the stem from the body...

[@grayfurnaceman]

On some valves, about all you can do is add packing over the old. GFM

[@jeepsblackpowderandlights4305]

Thanks for th3 video.. i had a feeling i could just turn these valves to close my r12 lines off.. and save whats in the system.. and then just simply swap in a new compressor.. fill it with oil.. and only need to vacuum the compressor itself.. then open the valves and refill with a little r12

[@Pretzel114]

Great Video, I am just learning and just read about these. Cleared up the back seat and front seat for me real good. Thanks so much.

[@patrickrhodes8227]

To front seat the valve. Is it reverse thread or normal threading?

[@grayfurnaceman]

Righty tighty, lefty loosey. GFM

[@fernandoescobar692]

So if I want to vacuum the system what should be the right position of the king valve ?

[@grayfurnaceman]

Mid point. GFM

[@fernandoescobar692]

@@grayfurnaceman thank you, it's clear now.

[@mikerefrigeration5736]

So just because a king valve is backseated doesnt mean it still wont leak from the packing? Can I crank the packing down like you would a leaky flare nut? I dealt with one today and I was a little weary of cranking it too tight. I tightened the packing, and I also put a little pipe dope on the service cap and tightend that pretty good.

[@grayfurnaceman]

If it is manufactured in can leak. By the way don't waste your time putting sealer on straight threads. The only threads that are sealed by pipe dope are tapered. GFM

[@charlieparker5678]

Thank you for uploading this. Studying HVACR so huge help.

[@SombraLocs]

How do you get to free them up when they get stuck and don't want to front or back seat?

[@grayfurnaceman]

Some of the valves have packing that can be removed and replaced, but that is probably not the reason yours is stuck. In any case, the unit will probably have to have the refrigerant removed and the valve replaced. GFM

[@grayfurnaceman]

Thanks for the support. GFM

[@joecox9958]

if the video is correct, then when valve is front seated, will freon leaks from compressor?

[@grayfurnaceman]

A front seated valve isolates the compressor from the system. The compressor is still open to the line tap. GFM

[@mikeryan4056]

Hey GFM. Today, at work, I charged a medium temp cooler at work. I back seated the king valve on the liquid receiver and proceeded to remove my high side gauge. Sure enough, I lost the whole charge. Was this valve malfunctioning? I was thinking about putting an access T there and charging from a different gauge port. why did that happen? Is it possible that it was a bad valve? I checked it many times to make sure it was back seated.

[@Tx500r]

Did you learn why you lost your charge, when you back seated your valve?

[@rejimathew1268]

what kind of tools need to use to loose the valve ?

[@grayfurnaceman]

You can use an adjustable wrench. There are also dedicated square wrenches available. GFM

[@percyoseimichael9838]

thanks very much

[@Joe-ws5el]

Welcome GFM

[@thirurajah1]

very good explanation

[@grayfurnaceman]

+thiru h Thanks for the support. GFM

[@grayfurnaceman]

There are a lot of techs that have never seen one. GFM

[@HfJax]

Wish I Saw this yesterday I was going crazy

[@grayfurnaceman]

Glad it helped. GFM

[@mikemace9644]

I wish they had this type of service valve on AC systems. Then we'd be able to pump our refrigerant into the evaporator and work on the condenser without having to add a Schrader valve. I started my career working with refrigeration. So many guys can't work with refrigeration. The biggest difference is that refrigeration works off of pressure rather than temps. As long as you know that temp and pressure are related you'd get it. I don't like being "married" to ice makers and walk in refrigerators or having emergency service calls at midnight because the walk in is down and they're gonna lose 1,000s of dollars of stock or beer.

[@grayfurnaceman]

Mike Mace It is a different breed of cat. Emergency calls are part of the job. You know that. GFM

[@randallamps]

I have a 1991 Jeep Cherokee Laredo with the inline six cylinder and I was trying to find out which way to open the roto-lock valve on back of the compressor on the low side so it will suck in the R-134 refrigerant. I have tried using a quarter inch open wrench and an adjustable wrench. Don't want to put too much pressure going either way. Not sure if righty tighty and loose lefty apply to this configuration. Would appreciate your input sir and Mike Mace, I like your Ace Frehley profile. Go Space Ace!

[@shrisales6099]

We are manufacturing these valves [e-mail]

[@Luzt.]

Where does the name "king valve" come from?

[@grayfurnaceman]

Beats me GFM

[@Luzt.]

@@grayfurnaceman Too bad. This was the only thing I did not know about them before watching the video.

[@scrambler350]

Thanks.

[@geojor]

thank you...

[@fieldpiece851]

work with thise for the first time not too long ago

[@ImTheRandomVideoGuy]

Hi can anyone direct me to a video of a recovery and charging of a system ? I am currently learning in class but I'm having trouble

[@grayfurnaceman]

I have a playlist on recovery and one on charging. Check my channel. Hope it helps. GFM

[@edwardhvacr4815]

You are part right in refrigeration work the king valve is not off the compressor its off the receiver outlet this where we hook gauge for the high side not the discharge service valve off the compressor .This where we could pump the system down put all the refrigerant in the receiver to service the system change the drier the txv or service the evaporator it always used in service the refrigerant system small or large system as long there a service king valve. Their a lot of more refrigeration valve in refrigeration work then AC work. You have know how the valve works before adjust the valve.This where must service technical get in trouble they don't know how the valve works in the system . If you want to learn a lot try on Parallel Rack System now you will learn a lot of refrigeration or cascade system that the freezer temperature is -220F with one compressor .

[@chrisscott1547]

"communicates" in the 100 year-old lexicon. Folks "get" it, but is momentarily distracting.

[@jtoeleraj]

Not informative Wasted my time. Find some time more to make good video. Like I have find time to comment

[@grayfurnaceman]

What did you want to see? GFM