We have a reciprocating compressor (five staged). It has poppet valves (check valves to prevent back flow)in its 2nd stage.
An issue that we have started facing is that when first stage outlet is cooled by interstage cooler and sent to KOD installed at the inlet of 2nd stage, we find an increase in the temperature of the gas leaving KOD before it enters into 2nd stage.
First we though that the stage poppet valves are bypassing and hot gas from 2nd stage cylinder is coming back into the suction line, but replacing these valves at times has not helped us in this regard.
Process guys hypothesized that there is Ammonium carbonate formation that causes hear release in the gas stream, but analysis of the condensate KOD has nullified this hypothesis.
If any one of you has faced such issue and knows how the issue may be resolved please share with me as we are facing load limitation due to 2nd stage outlet high temperature at increased load.