R507 system static pressure 1

[CRG]

What is the typical “standby pressure” AKA “static pressure” range for a R507 refrigeration system at 70 degF? Note: I am not using this information for charging the system. The information is need for a rough transient analysis during startup.

 

[pennpoint]

CRG
Depends upon your ambient temperature.

Best regards
pennpoint

 

[CRG]

pennpoint, sorry I did not make myself clear. What I meant by “static pressure” is when the AC system is deactivated (power disconnected) and has been off for some time. In other words, when the pressure is the same everywhere in the system and with an average temp of 70 degF for all the AC’s components.

 

[pennpoint]

CRG
Then I repeat my reply: It depends upon your ambient temperature. There are look up tables for psi @ 70 F.

Best regards
pennpoint

 

[waross]

The pressure will correspond to the hottest part of the system that contains liquid. The liquid will very slowly migrate to the coolest part of the system, or, at equal temperatures, the lowest part of the system. Very slowly. Hence crankcase heaters to keep refrigerant out of the oil in some systems with the receiver higher than the crank case. But usually, either of pennpoint's posts.
Look it up.
yours

 

[CRG]

Thanks waross. The point I missed is that all properly charged AC systems using R507 will have some liquid phased refrigerant condense in the coolest segment when the system is at static equilibrium. I did not know for certain that there were no exceptions on the initial charge always including some liquid phase for all possible ambient temperatures.

 

[waross]

If you have a system with so much volume that all the refrigerant may vaporize when at rest the static pressure will be lower and will also depend on the volume of the system, but I do not know of such a system. In such a case the pressure will depend on the individual system design.
respectfully.