Installing Gauges on Aircon Condensers

[Captain Ralph]

Is this what is referred to as a schrader valve?


Attachment 62699

A schrader valve is like a self sealing inner-tube air valve.

[Captain Ralph]

Here is a valve... similar on all seven condensers . This unit is low on gas. I guess thats why there is frost on valve.


Attachment 62699

There may be a more correct name, I just call this valve an assembly valve. In a closed position as delivered new, It would hold the pre-charged Freon gas and oil within the condensing station, After installation and the evaporator & lines are drawn down, These valves are opened, Releasing the gas to the evap and enabling the system to run.
Usually, never touched again,,, unless there are no service nipples available from around the compressor. Even then, the low assembly valve would be adjusted because it does not have a schrader valve in its service nipple.

This high pressure side valve has two 1/8" service nipples. The nipple under the red cap has the schrader valve in it. Here you would not need to use the assembly valve to check high pressure.

Look up around the compressor. There may be one or two more of these service nipples. Hopefully under blue & red caps.

Once that valve de-ices, there is a small gland nut at the base of the valve stem. Like an old hose bib, tighten that down to stop your gas leak.

[scottinsydney]

Thanks for photo of Schrader valve.....So what are the valves on our condensers called? They seem to have two parts... a shoulder that turns (and where bubble leak is) and the neck which also turns.

LOOKS LIKE CAPT RALPH HAS JUST ANSWERED THIS!

valve.jpg

[Captain Ralph]

Surely it cannot be difficult to service these yourself if you had the gauge set, a vacuum pump and a bottle of gas.

I remember prepping some boats to ship to AU.
The AU Customs was very through on the paper chase and required services before the boats were allowed in.
All A/C systems had to have the freon gas removed and re-charged with nitrogen.
Any ice maker, wine cooler or fridge that had a service nipple was included.
A stack of papers for each option was required also.

I had just assumed from that exercise the Australia rules were tougher on Freon than here in the US where it gets harder every day for DIY A/C services.
Check into your DIY R-22 & nitrogen supplies and laws, before making plans to fix your self.

[Captain Ralph]

Attachment 62702

Was just thinking;
A frozen high side valve?
Short stem leaking?

That valve may not have been returned to it's full & open operation position.
Compare that stem height to other systems valves. I think it should be up another 1/2 inch.

Our Bert is on the hill 60 miles away so I can not cheat and peek at my A/C units.
I'll be on Wills Hatt later today, I'll peek at his and double check my thoughts on stem height.

[cww]

I wouldn't bother. On a/c's that have permanently mounted gauges, they're always a prime source of leaks.

[Captain Ralph]

Found a valve for pictures. The stem is short in operate mode. In my pictures are a good look at the gland nut. Like a hose bib gland, let it un-freeze and snug it a bit.

Soapy water test it for leaks and tighten a lil at a time till it stops leaking.
Soapy water test the caps and connect also.

Ensure you rinse all the soap away, Some soap will act as a corrosive.

[Captain Ralph]

Here are examples of the service nipples with schroder valve I was trying to explain. Without messing with those installation valves, attach gauge hoses here.
Remember to always test for leaks after removing the hose.

It is the blue or low side you ad gas to. The High side should have a red cap. Look for discolored tubes to help ID the high (hot) side.
Unless I'm trouble shooting an issue or not familiar with a new to me unit, I rarely connect to the red or high side.

[Captain Ralph]

(Last technician did not close and test the valve properly and gas all leaked out within a month. I found this leak myself using the blue liquid leak finder. Utter waste of $2000 in service fees.)

$2000 in fees??

Whole bill or just service (Labor)?

Did you call them back to fix that leak they induced?
Exiting rule; Always check for leaks on anything touched before leaving.

[krush]

Thanks for photo of Schrader valve.....So what are the valves on our condensers called? They seem to have two parts... a shoulder that turns (and where bubble leak is) and the neck which also turns.

LOOKS LIKE CAPT RALPH HAS JUST ANSWERED THIS!

Attachment 62702

It's usually called a "king valve" or service valve. Proper terms are backseat, front seat, mid seat for positions.

The leak is not a huge deal. There is usually packing that can be tightened down to reduce the leak, the leaking should be minimized when the valve is backseating in normal operation positions, and then the cap is supposed to do the secondary seal to keep the gas in (use nylog)

Watch this video for better explanation.

https://www.youtube.com/watch?v=J0hyVhJyyD0