Soak Pressure???

[yoshi]

Hello everyone,

Im newbie here. Recently i was involved in some kind of refrigeration low temperature freezer project by using cascade system. general speaking, we have already conduct so many experiment. (Im newbie also in refrigeration system)

there is one term that i really dont understand about "soak pressure". simply say, we conduct experiment by running the freezer and set to the lowest temperature can be reached. of course we are using datalogger to record and analyze the performance (Im using many thermocouples and pressure transducer at the inlet outlet compressor) . and for the soak pressure is simply can be obtained by looking at the first data of pressure both in 1st and 2nd stage

Is there anyone who can explain what is it use for?? why that parameter become important??? some people say it soak pressure value is the 'effect' of charging certain amount of refrigerant. In what condition these term become important???

thank you everyone. hope i can get an answer from all of you

[NoNickName]

I think it's SUCTION pressure. :-)

[referable]

soak pressure is when you have allowed the unit to defrost for 24 to 48 hours. Then you attach your gauges to the second stage, with the unit still off, then you evaluate the pressure that you see on your gauges compared to the data plate and what pressures the data plate says for the second stage (low stage) and your guages should read no less than 20 psi below what the data plate says. If you read more than 20 psi then you have a possible leak on your low side. You can only perform a soak pressure test on the low side because the refrigerant in the low side is a high pressure refrigerant and will not condense into a liquid at room temp thus it stays in a vapor. Soak also means what refrigerant has soaked into the oil of that system thus soak pressure.

[yoshi]

so...the reason of measuring "soak pressure" is:
-as an indicator to detect leaking in our system, 2nd stage (low side) for high pressure refrigerant with offset around 20 psi.-

is there any purpose that make us need to measure soak pressure?

cant we do it also in high side (1st stage) due to refrigerant behavior?

is there any relationship between ambient temperature and soak pressure?

anyway, thanx for the reply.