Hi all,
I design a pressuriez oil system for an expander-compressors (acc. to API614 firth edition annex G & API617 Part4)
The operating pressure of the oil tank is > 60 barg with flammable gas.

The design pressure of the seal gas oil system and compressor/expander/bearing casing is > 90 barg

Following the performance test is it mandatory/recommended to do a Gas leak test at 90 barg (with N2 for exemple) on the Whole system (oil, seal gas, and casing line and tank) ? or is it only required for bearing and expander casing.
The API617 is not clear for PRESSURIIZED oil System ?

"API 614 Part 4-Expander-compressors
6.3.4 Assembled Machine Gas leakage Test
6.3.4.1 After the mechanical running test is completed, each completely assembled machine casing
intended for toxic or f1ammable gas service shall be tested for gas leakage. The assembled casing shaH
be pressurized to the lowest of the expander or compressor casing MAWP, held at this pressure for a
minimum of 30 minutes and subjected to a soap bubble test to check for gas leaks. The test shall be
considered satisfactory when no casing or casing joint leaks are observed.
NOTE These tests are intended to verify the integrity of the casing joints."

Regards