How to get a right vacuum

[Ratax]

Hi folks!

I would like to know what's the best way to right vacuum pump a direct-die system (single stage and cascade...).

[JSU]

What iam doing is attaching the blue hose to the low side then the red hose to the vacuum pump then the yellow hose to the refrigerant. Vacuum for a hour or so with a real vacuum pump or overnight with a compresser. Then purge the vacuum with a quick open and close of the refrigerant valve. Repeat process. Then vacuum once more (3rd time) and charge.

The reason for the odd way of attaching the hoses is that the yellow hose has no air in it so no air gets in the system. as apposed to taking the hose off of the vacuum pump and putting it on the refrigerant you allow air into the hose. Btw do not attach the red hose to the system unless there is pressure in it. Or else the system will suck in whatever air there is in the hose.

[JSU]

sounds good, ill do it that way i guess

[Ratax]

Thanks!

[Redwolf]

4 port manifold
red on high pressure
blue on low pressure
yellow on micron gauge
black 3/8" line on vacuum pump

With out a micron gauge theres no way to know how good of a vacuum you pulled.

[kayl]

a good practice when vacuuming is to do triple evac
each time letting gas in high side to about 0PSIG
then vacuuming through lowside

ideal is to use dry nitrogen if you can

[Ratax]

The triple evac could be done with r12? And what about pressure tests in the system with this gas?

I talk in it because I have here a brand new, non refilable, 30lbs, r12 full tank... it was here in the company to do some repairs by the technic, but has no use anymore...
I have some more brand new stuff but for r12 (solenoid valve, drier, thermostat, etc...). Can it be used with other gases?

[kayl]

r12 is an older refrigerant and very damaging to the atmosphere.
20x more than r22
i wouldnt recomend using it to leak testing for that reason
something like propane would be better.

a triple evac could be done with any refrigerant though

[oc_nightmare]

Originally posted by Ratax
I have some more brand new stuff but for r12 (solenoid valve, drier, thermostat, etc...). Can it be used with other gases?

yep, r22 and r290.
id like more to have a full tank of r22 because it has better temps and it is not a cfc as r12.... but if u have a bottle of r12 and r12 equipement u could give it a try but not to leak testing :p:
stay cool:toast:

[Ratax]

Can I transform this non refilable tank so I can refill it with other gas?

When using propane, can we use it directly from the regular botles used in home in the kitchen? Just the reductor and a charging hose (adapted)? Or are we talking in "other" propane?

oc_nightmare, do you know someone with a recovery tank so I can get this gas out of this? 13,6Kg of this gas to the atmosphere...

[JSU]

Originally posted by Ratax
Can I transform this non refilable tank so I can refill it with other gas?
chilly1 I think you should answer this one ;) (you must have said it 100+ times)

[oc_nightmare]

for the tests in my chillers u was using a bottle of those in the kitchen with a shradder valve on the hose... it worked fine but i dont know if it is really pure r290.... try the galp blue bottles ;)
almost every hvac tecnics iv talked to use a recovery tank and other recovery equipement... if u talk with one about the r12, im sure he can borrow u his....

[Ratax]

A valve in the hose, but with the reductor in, right?
Thanks