20.
Read the pressure on the sample outlet pressure gauge (
Figure 2
or
Figure 3
). To determine the current inline relief
setting, subtract this pressure reading from the pipeline pressure.
When sampling into a Welker Constant Pressure Cylinder, the pressure gauge should read approximately 200 psig below
pipeline pressure at start-up.
21.
If the current inline relief setting is approximately 200 psig, the inline relief does not need to be adjusted; continue to
step 22. If the current inline relief setting is anything other than approximately 200 psig, the inline relief must be
adjusted; repeat steps 14–21until the inline relief is set to approximately 200 psig.
Purging the Sample Cylinder
Refer to Gas Processors Association (GPA) Standard 2166-86,
Obtaining Natural Gas Samples for Analysis by Gas
Chromatography
, for further instructions on GPA-recommended purge methods.
This method is only advisable if the sample cylinder will be used in the same location to sample the same type of product.
22.
Purge the sample cylinder.
To purge the Welker SC Single Cavity Cylinder, continue to step 23.
To purge the Welker Constant Pressure Cylinder, proceed to step 30.
SC
23.
Slowly open bypass valve C (
Figure 2
or
Figure 3
). Check for leaks and repair as necessary.
24.
Close bypass valve C.
25.
Open the outlet valve on the SC.
26.
Open bypass valve C.
27.
Open the inlet valve on the SC.
28.
Close bypass valve C.
29.
Proceed to step 35.
16
IOM-022
MODEL: GSS-4PM
REV: F
13839 West Bellfort Street, Sugar Land, TX 77498
welker.com
Service Department 281.491.2331
