A/C lines - how much pressure?

[Jeff A.]

Wondering - how much pressure is in the a/c system?
What is the highest pressure that the seals need to withstand?

[Tom L.]

Re: A/C lines - how much pressure?

On a HOT day, idling in traffic, the high pressure side of the system will reach 225 psi. unless there is a High pressure cut out. For R12 and their replacements this is well above acceptable operating pressures but auto manufacturers have been designing systems that operatre at these pressures for years. That's why most newer cars do have a high pressure cut out, I don't believe that older vettes have them.

[Jeff A.]

Re: A/C lines - how much pressure?

Which of the components are high side, and which are low side?
Do all of these components need to withstand 250psi? The evaporator, condenser, dryer, POA, Exp valve.

[Tom L.]

Re: A/C lines - how much pressure?

The High side includes the line from the compressor to the condensor, the condensor and all lines and components leading to and including the inlet of the expansion valve. The low side begins at the outlet of the expansion valve and includes the evaporator, POA valve and lines to the compressor. The low side will unlikely see anything over 100 psi. Just curious, why do you ask?

[Jeff A.]

Re: A/C lines - how much pressure?

I am going to start rebuilding my original dryers. I have about 50 cores.
I want to be sure I test to the correct pressure - so the dryer will only see 100 psi?

[Dick W.]

Re: A/C lines - how much pressure?

You probably need to test to 350 psi. An improperly charged system can see over 275#. I hope you are testing in a tank, not out in the open. A rupture of a drier could be catastropic.

[Tom L.]

Re: A/C lines - how much pressure?

Dick is very correct about pressure testing. In particular, the drier will be a possible serious hazard. During operation it will be "Liquid full' meaning there is no airspace. When a container becomes liquid full pressure is applied to the container hydraulicly not pneumatically and the maximum pressure that it can hold can be reached quickly and a very violent explosion results.

I studied in college for a career in commercial refrigeration and a professor showed a picture of a van that had a 30 lb. Cylinder become liquid full and explode (Due to very high temps) and the trucks walls and roof were peeled back like they were tinfoil. I think it was a test that Dupont did in developing the cylinders that are in use for today.

Anyway, not that a corvette would be damaged in the same way as the van, I'm sure there would be a mess in the right front corner of the car!

I would be very careful especially if you were going to sell them. Lawyers love that kind of stuff! Good luck!