58
downtube and FP-25 fittings to ensure all components are fully seated.
» If the internal flow stream pressure reported by the FP-25 (in absolute
or gauge units) did drop properly, roughly matching the pressure values
reported by the sampler, then there may be a smaller internal leak. Conduct
the internal leak check to diagnose further.
» If the FP-25 showed significant flow during the leak check, then there may
be a leak through the leak check adapter or its valve. Ensure both the FP-25
and the leak check adapter are firmly connected to each other and the
downtube. Verify that the valve of the leak check adapter is closed.
Note: During leak checks in Direct Mode, the FP-25 will provide flow
readings in addition to pressure readings, but these are not
comparable to any flow readings reported by the sampler. Whereas the
sampler is measuring flow at the end of the flow path, the FP-25's
location right after the closed valve on the leak check adapter prevents
it from providing meaningful flow measurements during leak checks.
3.3
Open the valve on the leak check adapter when instructed.
3.4
Record your data.
Standard Operating Procedures (SOPs)
Verifying Internal Pressure during Leak Checks
