Atlas Copco ZT22 Z tooth compressor

Questions & AnswersAtlas Copco ZT22 Z tooth compressor
Cas Staff asked 4 years ago

Hello. I have a problem with an Atlas Copco ZT22 Compressor. The unit operates normally until it is switched into the loading mode.

At that time the intercooler pressure jumps from 30 to 59 psi and the low pressure safety valve starts to pop off.

The compressor continues to run and it does build up pressure but the low pressure pop off continually blows off. The low pressure safety valve was recently replaced and the operation returned to normal for a few days then the error repeated. There are no alarms displayed on the operation screen and all the other monitored sensors seem to be within normal range, ie, temperatures, oil pressure, etc.

The load/unloader module appears to operate correctly and unloads when the set pressure is achieved. I suspect there is a problem with the High-pressure compressor element? Any feedback you could provide would be greatly appreciated!


2 Answers
Cas Staff answered 4 years ago

Hi Kirk,

Difficult to diagnose such a problem from behind my PC 🙂

It looks like your intercooler pressure is way too high. It should be 2.5 bar (36psi) when loaded.

Since you7 say your temperatures are OK, this would indicate a faulty high pressure element, as you suggested.

These are the temperatures and pressure that Atlas Copco says are normal for your ZT22:

– Oil pressure: 2.4 bar
– Intercooler pressure: 2.5 bar
– LP element outlet temp: 167 degrees Celsius
– HP inlet temp (intercooler temp): 32 degrees Celsius.
– HP outlet temp: 166 degrees Celsius,

Strange that replacing the safety valve helped solve the problem for a while? Did the intercooler pressure actually go down during that period?

Good luck and sorry I can’t be of more help. Let me know if you fixed the problem.

oragon bekool answered 3 weeks ago

Have my xas67 model and each day the air pressure dropping rapidly,any hints really appreciated and thank you

Your Answer