Single gauges for hooked to a critically charged system

[marter]

Ive seen them but cant remember where. Used to checked the pressure on a system that hold a few ounces of gas. some pics would be nice too

[Milk man]

Regular guage and a fitting from most supply houses.

[walterc]

We used to crimp the process/charging tube and braze it shut if it was that close.

I also had a tool for GE systems you screwed onto a special fitting that allowed you to close the fitting off before removing the hoses- got stolen- will never find another one. Dates back to the 40's-60's anyway and not used anymore I think.

Using ball valves or placing a new rubber seal in the hose end where it closes the valve core before the seal breaks is another way.


Haven't done much of it lately (years)- perhaps there is a better way.

[marter]

what about those single digital gauges ?

http://yellowjacket.com/product/853

does anyone else make something like this.

mostly going to be use for small 404a/134a units. I like the accuracy

[jpsmith1cm]

Those are nothing but a digitized bourdon tube gauge.

[kiwireeferman]

Who's going to be first to remote the transducers from a Digi-cool instrument. Would be real easy to do. a,la Robinair and Cooper.

[marter]

Who's going to be first to remote the transducers from a Digi-cool instrument. Would be real easy to do. a,la Robinair and Cooper.

thats what im wanting. i get the precision of a digi. but without the lose of gas on a 12oz system

[gravity]

ball valves. i close both sides unhook very quickly and attach liquid hose to vapor line and let it dump back into the unit. i love doing it this way.

[jpsmith1cm]

ball valves. i close both sides unhook very quickly and attach liquid hose to vapor line and let it dump back into the unit. i love doing it this way.

On a critical charge unit, this is a big mistake.

Once you've trimmed the charge to where it needs to be, pull the hoses off and walk away!

If you put that high side liquid in, you just over charged the unit.

[Peztoy]

Would you consider installing good quality permanent gauges.

[kiwireeferman]

On a critical charge unit, this is a big mistake.

Once you've trimmed the charge to where it needs to be, pull the hoses off and walk away!

If you put that high side liquid in, you just over charged the unit.

I believe you need to qualify that statement.

Critical charge to me means manufacturer has stated the volume of refrigerant the system should contain.
If the charge has been weighed, or put in with a charging cylinder how can it be overcharged by bleeding the high side hose contents to the low side.

[jpsmith1cm]

I believe you need to qualify that statement.

Critical charge to me means manufacturer has stated the volume of refrigerant the system should contain.
If the charge has been weighed, or put in with a charging cylinder how can it be overcharged by bleeding the high side hose contents to the low side.

You weighed in the exact charge, accounting for the volume of refrigerant contained in the hoses.

You have also verified that the auperheat and subcooling are correct.

Now, you're going to add a couple of extra ounces of refrigerant by emptying the hoses back into the unit?

Yep, that's an overcharge.

[kiwireeferman]

Don't think so. The system calls for a 30oz charge. You charge till the scale shows 30oz has left the can. You turn off the valve on the can.
Where did this magical 2oz come from.

You are not measuring what has gone in, you are measuring what has left the jug.

I don't believe you can use a scale to weigh very small volumes anyway.
Hoses only need to move slightly and your up or down a 20-30 grams.