Welker GSS-4PM User manual

INSTALLATION, OPERATION, ANDMAINTENANCEMANUAL
WELKER COMPOSITEGASSAMPLER
MODEL
GSS-4PM

DRAWING NUMBERS
AD617BS
AD617CL

MANUAL NUMBER
IOM-022

REVISION
Rev. F, 10/22/2018

TABLEOFCONTENTS
2IOM-022 MODEL: GSS-4PM REV: F 13839 West Bellfort Street, Sugar Land, TX 77498 welker.com Service Department 281.491.2331
Copyright © 2018 Welker, Inc. All rights reserved. Welker®, W Welker®, W logo, WelkerScope®, Welker Jet®, and OdorEyes® are registered trademarks of Welker, Inc.
 SAFETY 3
1. PRODUCT INFORMATION 4
1.1 Introduction 4
1.2 Product Description 4
1.3 Specifications 5
1.4 Equipment Diagrams 6
  
2. INSTALLATION & OPERATION 9
2.1 Before You Begin 9
2.2 Installation 10
2.3 Start-Up Procedures 13
  
3. MAINTENANCE 19
3.1 Before You Begin 19
3.2 Maintenance 20
3.3 Troubleshooting 25
3.4 Purging and Cleaning the Sample Cylinder 27
  
 APPENDIX 28
 A: Referenced or Attached Documents 28


IMPORTANTSAFETYINFORMATION
READALLINSTRUCTIONS
Notes emphasize information and/or provide additional information to assist the user.
Caution messages appear before procedures that could result in damage to equipment if not observed.
Warning messages appear before procedures that could result in personal injury if not observed.
This manual is intended to be used as a basic installation and operation guide for the Welker Composite Gas Sampler, GSS-4PM. For comprehensive instructions,
please refer to the IOM Manuals for each individual component. A list of relevant component IOM Manuals is provided in Appendix A of this manual.
The information in this manual has been carefully checked for accuracy and is intended to be used as a guide for the installation, operation, and maintenance of
the Welker equipment described in this manual. Correct installation and operation, however, are the responsibility of the end user. Welker reserves the right to make
changes to this manual and all products in order to improve performance and reliability.
BEFOREYOUBEGIN
Read these instructions completely and carefully.
IMPORTANT - Save these instructions for local inspector's use.
IMPORTANT - Observe all governing codes and ordinances.
Note to Installer - Leave these instructions with the end user.
Note to End User - Keep these instructions for future reference.
Installation of this Composite Gas Sampler is of a mechanical and electrical nature.
Proper installation is the responsibility of the installer. Product failure due to improper installation is not covered under the warranty.
If you received a damaged Composite Gas Sampler, please contact a Welker representative immediately.
Phone: 281.491.2331
Address: 13839 West Bellfort Street
Sugar Land, TX 77498
SAFETY
3IOM-022 MODEL: GSS-4PM REV: F 13839 West Bellfort Street, Sugar Land, TX 77498 welker.com Service Department 281.491.2331

1.1 Introduction
We appreciate your business and your choice of Welker products. The installation, operation, and maintenance liability for this
equipment becomes that of the purchaser at the time of receipt. Reading the applicable Installation, Operation, and
Maintenance (IOM) Manuals prior to installation and operation of this equipment is required for a full understanding of its
application and performance prior to use.*
If you have any questions, please call Welker at 1-281-491-2331.
*The following procedures have been written for use with standard Welker parts and equipment. Assemblies that have been modified may have additional
requirements and specifications that are not listed in this manual.
1.2 Product Description
The Welker GSS-4PM Composite Gas Sampler is a self-purging positive displacement pump designed to extract samples from
the center one-third (¹⁄₃) of a pressurized gas pipeline and collect them in a connected sample cylinder.
The compact design of this probe mounted sampler eliminates long tubing runs and sample lag time. By minimizing the distance
between the product source and the collection head, the GSS-4PM ensures quality sample grabs. With every actuation, pressure
is applied to the Vanishing Chamber™ collection cup, collapsing the cup and fully displacing the trapped sample into the sample
cylinder.
The GSS-4PM can be connected to a customer Programmable Logic Controller (PLC) or other signal control system to operate the
solenoid. Alternatively, the GSS-4PM can be supplied with a Welker 4P Sample Frequency Controller or a Welker 6Tc
Timer/Controller, both of which are capable of operating the solenoid for timed or proportional to flow sampling.
In locations where the process gas is not clean and dry, the GSS-4PM can be configured for operation by an auxiliary instrument
air supply. For such locations, the Welker LE-2SSKO Probe Mounted Liquid Eliminator is recommended in place of the standard
probe, as it removes free liquids, condensed hydrocarbons, glycol, and amines from gas samples, thus ensuring the collection of
representative samples and protecting the sampler.

For this manual, the term "PLC," or Programmable Logic Controller, will be used to refer to the PLC, DCS, or other signal control
system used by the customer to activate and operate the solenoid.
Welker may custom design the GSS-4PM to suit the particular application and specifications of each customer.
SECTION 1: PRODUCTINFORMATION
4IOM-022 MODEL: GSS-4PM REV: F 13839 West Bellfort Street, Sugar Land, TX 77498 welker.com Service Department 281.491.2331

1.3 Specifications

The specifications listed in this section are generalized for this equipment. Welker can modify the equipment according to your
company's needs. Please note that the specifications may vary depending on the customization of your equipment.
Table 1: GSS-4PM Specifications
Products Sampled Natural Gas and Other Gases Compatible With the Materials
of Construction
Materials of Construction 316/316L Stainless Steel, PTFE, and Viton®
Others Available
Maximum Allowable Operating Pressure With LE-2SSKO: 1440 psig @ -20 °F to 120 °F (99 barg @ -28 °C to 48 °C)
Standard: 2160 psig @ -20 °F to 120 °F (148 barg @ -28 °C to 48 °C)
Pipeline Connection
½" MNPT
¾" MNPT (Standard)
1" MNPT
Electrical Connection
AC 110 V
DC 6 V
DC 12 V (Standard)
DC 24 V (Standard)
Sample Volume
0.065 cc Vanishing Chamber™ Collection Cup
0.22 cc Vanishing Chamber™ Collection Cup (Standard)
0.5 cc Vanishing Chamber™ Collection Cup
1.0 cc Vanishing Chamber™ Collection Cup
1.5 cc Vanishing Chamber™ Collection Cup
Operation Diaphragm-Operated Motor
Features
Inline Relief
Integrated Bypass Manifold With Valve
Outlet Pressure Gauge
Regulator With Relief and Pressure Gauge
Options
4-Way Solenoid Valve (Standard)
Manifold for Welker SC SingleCavity Cylinder (Standard)
Welker 4P Sample Frequency Controller
Welker 6Tc Timer/Controller
Welker LE-2SSKO Probe Mounted Liquid Eliminator (Standard)
5IOM-022 MODEL: GSS-4PM REV: F 13839 West Bellfort Street, Sugar Land, TX 77498 welker.com Service Department 281.491.2331

1.4 Equipment Diagrams
Figure 1: GSS-4PM Connections Diagram
6IOM-022 MODEL: GSS-4PM REV: F 13839 West Bellfort Street, Sugar Land, TX 77498 welker.com Service Department 281.491.2331

Figure 2: GSS-4PM With Standard Probe
Figure 3: GSS-4PM With LE-2SSKO Probe Mounted Liquid Eliminator
7IOM-022 MODEL: GSS-4PM REV: F 13839 West Bellfort Street, Sugar Land, TX 77498 welker.com Service Department 281.491.2331

Figure 4: LE-2SSKO Probe Mounted Liquid Eliminator Diagram
8IOM-022 MODEL: GSS-4PM REV: F 13839 West Bellfort Street, Sugar Land, TX 77498 welker.com Service Department 281.491.2331

2.1 Before You Begin

After unpacking the unit, check the equipment for compliance and any damage that may have occurred during shipment.
Immediately contact a Welker representative if you received damaged equipment.

When sealing fittings with PTFE tape, refer to the proper sealing instructions for the brand used.


All electrical connections must meet local and national electric codes, and excessive weight added to the conduit run must be
supported.

1. The installation instructions are written with the assumption that the sampler has been purchased as part of a complete
sampling system. If the sampler has been purchased individually, a sampling system should be constructed in a fashion
compatible with the instructions in this Installation, Operation, and Maintenance (IOM) Manual.
2. The sample probe should be located in the least turbulent area of the flowing stream available (i.e., not in a header or
blow-down stack and away from obstructions, elbows, and partially closed valves).
3. Typically, the Welker GSS-4PM is installed with a single probe. The unique self-purging design of the GSS-4PM uses
process gas to supply the solenoid, thus purging the sample line prior to each sample grab. If auxiliary instrument air is
used to supply the solenoid, the customer must have a return port downstream of a moderate pressure drop (e.g., an
orifice plate or control valve) to create a bypass for the sampler, which will allow for a "real-time" sample to be taken
with each actuation of the sampler.
SECTION 2: INSTALLATION&OPERATION
9IOM-022 MODEL: GSS-4PM REV: F 13839 West Bellfort Street, Sugar Land, TX 77498 welker.com Service Department 281.491.2331

2.2 Installation
1. Depressurize the pipeline.

The pipeline must be depressurized prior to installing and removing the unit.

2. Ensure that all valves on the GSS-4PM are closed.
3. Wrap the threads of the threaded pipeline connection with PTFEtape.
4. Install the GSS-4PM to the pipeline. If the GSS-4PM is equipped with the optional Welker LE-2SSKOProbe Mounted
Liquid Eliminator, ensure that it is installed so that the stinger is downstream of the direction of product flow (Figure 5).

Figure 5: Correct Installation of GSS-4PM With LE-2SSKO

5. As necessary, connect from the solenoid exhaust tubing to a flare (Figure 1).

If the process gas used to actuate the sampler cannot be safely vented to the atmosphere, Welker recommends connecting
from the solenoid exhaust tubing to a flare.

6. If the GSS-4PM is equipped with a Welker 4P Sample Frequency Controller, refer to the Installation, Operation, and
Maintenance (IOM) Manual for the 4P for wiring instructions.
7. If the GSS-4PM is equipped with a solenoid, connect from the PLC to the solenoid (Figure 1).
8. If process gas will be used to actuate the sampler, the sample cylinder may now be installed.

If a Welker SCSingle Cavity Cylinder will be used for sample collection, proceed to step 15.
If a Welker Constant Pressure Cylinder will be used for sample collection, proceed to step 18.

10 IOM-022 MODEL: GSS-4PM REV: F 13839 West Bellfort Street, Sugar Land, TX 77498 welker.com Service Department 281.491.2331

9. If an auxiliary instrument air supply will be used to actuate the sampler, continue to step 10.

The GSS-4PM is designed to use process gas as the instrument supply and does not require an auxiliary instrument air supply.
However, if process gas is not clean and dry and/or cannot be safely vented to the atmosphere, Welker recommends the use of
an auxiliary instrument air supply.
Using an Auxiliary Instrument Air Supply (Optional)
10. Remove the elbow connecting the regulator to the base, and then tube from the instrument supply port in the base to
the required downstream return. This creates a bypass for the sampler, which will allow for a "real-time" sample to be
taken with each actuation of the sampler.
11. Connect the customer-supplied clean, dry auxiliary instrument air supply to the open port on the regulator.
12. Regulate the auxiliary instrument air supply to the pressure appropriate for the application. The auxiliary instrument air
supply should be between 40 and 60 psig.

In applications where pipeline pressure is greater than 1500 psig, additional instrument air may be required to take a sample.
Increase the instrument air supply and adjust the regulator relief valve as necessary. To protect the diaphragm motor, the
instrument air supply should not exceed 100 psig.

13. Set the regulator relief valve to approximately 85 psig. Refer to the Installation, Operation, and Maintenance (IOM)
Manual for the regulator relief valve for instructions on setting the relief.
14. The sample cylinder may now be installed.

If a Welker SCSingle Cavity Cylinder will be used for sample collection, continue to step 15.
If a Welker Constant Pressure Cylinder will be used for sample collection, proceed to step 18.
11 IOM-022 MODEL: GSS-4PM REV: F 13839 West Bellfort Street, Sugar Land, TX 77498 welker.com Service Department 281.491.2331

Installing the Sample Cylinder
SC Single Cavity Cylinder
15. Ensure that the inlet and outlet valves on the SC are closed.
16. Install the inlet valve of the SC to the cylinder hanger on the manifold (Figure 1).
17. Installation is now complete.
Constant Pressure Cylinder
18. Ensure that the pre-charge and product inlet valves on the constant pressure cylinder are closed.
19. Tube from the pre-charge pressure supply to the pre-charge inlet valve on the constant pressure cylinder.

If the GSS-4PM is equipped with the standard probe and process gas will be used to pre-charge the constant pressure cylinder,
remove the plug from the probe base, and then tube from this port to the pre-charge valve on the constant pressure cylinder.
Welker recommends first installing a valve to the port on the probe base.

If the GSS-4PM is equipped with the optional LE-2SSKO and process gas will be used to pre-charge the constant pressure
cylinder, remove the plug from the back of the regulator, and then tube from this port to the pre-charge valve on the constant
pressure cylinder.

If the optional auxiliary instrument air supply will be used to pre-charge the constant pressure cylinder, remove the plug from
the back of the regulator, and then tube from this port to the pre-charge valve on the constant pressure cylinder.

20. Tube from the sample outlet on the base of the GSS-4 to the product inlet valve on the constant pressure cylinder.
21. Pre-charge the constant pressure cylinder. Refer to the Installation, Operation, and Maintenance (IOM) Manual for the
constant pressure cylinder for instructions on pre-charging the constant pressure cylinder.
12 IOM-022 MODEL: GSS-4PM REV: F 13839 West Bellfort Street, Sugar Land, TX 77498 welker.com Service Department 281.491.2331

2.3 Start-Up Procedures
1. Ensure that all valves on the GSS-4PM are closed.
2. Pressurize the pipeline.
3. As necessary, adjust the inline relief. If the inline relief does not need to be adjusted, proceed to step 22.

If a Welker SCSingle Cavity Cylinder will be used for sample collection, continue to step 4.
If a Welker Constant Pressure Cylinder will be used for sample collection, proceed to step 11.
Setting the Inline Relief

The inline relief is designed to allow product to flow in one direction only. Acting as a check valve, the inline relief will ensure
that sample pumped into the sample cylinder cannot flow back to the pipeline even if pipeline pressure drops.

Figure 6: Inline Relief Adjustment Diagram
13 IOM-022 MODEL: GSS-4PM REV: F 13839 West Bellfort Street, Sugar Land, TX 77498 welker.com Service Department 281.491.2331

SC Cylinder
4. Remove the buttonhead screw and washer seal from the end of the base.
5. Insert a hex key through the base to the spring adjuster.
6. Allow full pipeline pressure to reach the GSS-4PM. Check for leaks and repair as necessary.

If the GSS-4PM is equipped with a standard probe, slowly open sample pump isolation valve D (Figure 2).
If the GSS-4PM is equipped with the optional LE-2SSKO, slowly open inlet (P₁) valve A and return (P₂) valve B (Figure 3).

7. Turn the spring adjuster to adjust the spring tension until no gas bleeds through, and then turn the spring adjuster
clockwise another full turn.

When sampling into a Welker SC Single Cavity Cylinder, the inline relief must be set to approximately 100 psig above pipeline
pressure.

To increase spring tension and raise the relief set point, turn the spring adjuster clockwise.
To decrease spring tension and lower the relief set point, turn the spring adjuster counterclockwise.

Each full clockwise turn of the spring adjuster increases spring tension approximately 100 psig.

8. Replace the washer seal, and then return the buttonhead screw to the base.
9. Verify that the sample outlet pressure gauge reads the pressure appropriate for the sample cylinder (Figure 2 or Figure
3). This reading indicates that the inline relief is holding and that sample cannot flow back to the pipeline.

When sampling into a Welker SC Single Cavity Cylinder, the pressure gauge should read 0 psig at start-up.

10. Proceed to step 22.
14 IOM-022 MODEL: GSS-4PM REV: F 13839 West Bellfort Street, Sugar Land, TX 77498 welker.com Service Department 281.491.2331

Constant Pressure Cylinder
11. Allow full pipeline pressure to reach the GSS-4PM. Check for leaks and repair as necessary.

If the GSS-4PM is equipped with a standard probe, slowly open sample pump isolation valve D (Figure 2).
If the GSS-4PM is equipped with the optional LE-2SSKO, slowly open inlet (P₁) valve A and return (P₂) valve B (Figure 3).
12. 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.

13. If the current inline relief setting is approximately 200 psig, the inline relief does not need to be adjusted; proceed to
step 22. If the current inline relief setting is anything other than approximately 200 psig, the inline relief must be
adjusted; continue to step 14.
14. Isolate the GSS-4PM from pipeline pressure.

If the GSS-4PM is equipped with a standard probe, close sample pump isolation valve D (Figure 2).
If the GSS-4PM is equipped with the optional LE-2SSKO, close inlet (P₁) valve A and return (P₂) valve B (Figure 3).

15. Remove the buttonhead screw and washer seal from the end of the base.
16. Insert a hex key through the base to the spring adjuster.
17. Turn the spring adjuster to adjust the spring tension.

When sampling into a Welker Constant Pressure Cylinder, the pressure gauge should read approximately 200 psig below
pipeline pressure at start-up.

To increase spring tension and raise the relief set point, turn the spring adjuster clockwise.
To decrease spring tension and lower the relief set point, turn the spring adjuster counterclockwise.

Each full clockwise turn of the spring adjuster increases spring tension approximately 100 psig.

18. Replace the washer seal, and then return the buttonhead screw to the base.
19. Allow full pipeline pressure to reach the GSS-4PM.

If the GSS-4PM is equipped with a standard probe, slowly open sample pump isolation valve D (Figure 2).
If the GSS-4PM is equipped with the optional LE-2SSKO, slowly open inlet (P₁) valve A and return (P₂) valve B (Figure 3).

15 IOM-022 MODEL: GSS-4PM REV: F 13839 West Bellfort Street, Sugar Land, TX 77498 welker.com Service Department 281.491.2331

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

Constant Pressure Cylinder
30. Open the pre-charge supply to the constant pressure cylinder. Check for leaks and repair as necessary.

If process gas will be used to pre-charge the constant pressure cylinder, slowly open sample pump isolation valve D (Figure 2).
If the optional auxiliary instrument air supply will be used to pre-charge the constant pressure cylinder, slowly open the supply
to the constant pressure cylinder.

31. Slowly open the pre-charge valve on the constant pressure cylinder. This supplies pre-charge pressure to the constant
pressure cylinder and forces the constant pressure cylinder piston to the product side of the cylinder.
32. Open the product inlet valve on the constant pressure cylinder.
33. Open the process connection to the constant pressure cylinder. Check for leaks between the pipeline and the constant
pressure cylinder and repair as necessary.

If the GSS-4PM is equipped with a standard probe, slowly open sample pump isolation valve D (Figure 2).
If the GSS-4PM is equipped with the optional LE-2SSKO, slowly open inlet (P₁) valve A and return (P₂) valve B (Figure 3).

34. Purge the tubing between the GSS-4PM and the constant pressure cylinder.

If the constant pressure cylinder is equipped with a purge valve, open the purge valve for approximately three to five (3–5)
seconds to purge the tubing, and then close the purge valve. Welker recommends plugging the purge valve when not in use.
If the constant pressure cylinder is not equipped with a purge valve, the tube fitting at the product inlet of the constant
pressure cylinder may be cracked. However, Welker recommends installing a tee with a valve between the sample outlet on the
GSS-4PM and the product inlet on the constant pressure cylinder to enable the tubing to be purged.
17 IOM-022 MODEL: GSS-4PM REV: F 13839 West Bellfort Street, Sugar Land, TX 77498 welker.com Service Department 281.491.2331

Testing the GSS-4PM
35. Ensure that bypass valve C is closed (Figure 2 or Figure 3).
36. Close the product inlet valve on the sample cylinder.
37. Actuate the GSS-4PM.
38. Observe the sample outlet pressure gauge (Figure 2 or Figure 3). Allow pressure to build above line pressure, and then
let the GSS-4PM sit for several minutes.
39. After several minutes, read the pressure on the sample outlet pressure gauge. If the pressure has dropped, check the
GSS-4PM for leaks and repair as necessary. If the pressure has not dropped, the unit is ready to be placed into
operation.
40. Bleed off the test pressure from the sample cylinder.
41. Open the product inlet valve on the sample cylinder.
Preparing for Sampling
42. Set the signal control system to the desired sampling frequency based on the sampling actuation equations provided
(Figure 7). If the GSS-4PM is equipped with a 4P, refer to the Installation, Operation, and Maintenance (IOM) Manual for
the 4P for instructions on setting the sampling frequency. If the GSS-4PM is equipped with a 6Tc, refer to the
Installation, Operation, and Maintenance (IOM) Manual for the 6Tc for instructions on setting the sampling frequency.

Figure 7: Gas Sampling Equations

Note that the sample volume of the Vanishing Chamber™ collection cup could be 0.065 cc, 0.22 cc, 0.5 cc, 1.0 cc, or 1.5 cc.

43. The GSS-4PM is now operational.
18 IOM-022 MODEL: GSS-4PM REV: F 13839 West Bellfort Street, Sugar Land, TX 77498 welker.com Service Department 281.491.2331

3.1 Before You Begin
1. Welker recommends that the unit have standard maintenance every six (6) months under normal
operating conditions. In cases of severe service, dirty conditions, excessive usage, or other unique applications that
may lead to excess wear on the unit, a more frequent maintenance schedule may be appropriate.
2. Prior to maintenance or disassembly of the unit, it is advisable to have a repair kit available for repairs of the system in
case of unexpected wear or faulty seals.

New seals supplied in spare parts kits should be lightly lubricated before being installed to ease the installation of the seals and
reduce the risk of damage when positioning them on parts. Wipe excess lubricant from the seals, as it may adversely affect
analytical instrument results.

For sample-exposed seals, Welker recommends non-hydrocarbon-based lubricants, such as Krytox®.
For non-sample-exposed seals, Welker recommends either non-hydrocarbon-based lubricants or silicone-based lubricants, such
as Molykote® 111.

After the seals are installed, the outer diameter of shafts and inner diameter of cylinders may be lubricated to allow smooth
transition of parts.

3. All maintenance and cleaning of the unit should be performed on a smooth, clean surface.
4. Welker recommends having the following tools available for maintenance. Please note that the exact tools required may
vary by model.
a. ½" Wrench
b. 6" Adjustable Wrench
c. Adjustable Pliers
d. Anti-galling Compound
e. Hex KeySet
f. Seal Pick
g. Snap Ring Pliers
h. Threadlocker
SECTION 3: MAINTENANCE
19 IOM-022 MODEL: GSS-4PM REV: F 13839 West Bellfort Street, Sugar Land, TX 77498 welker.com Service Department 281.491.2331

20 IOM-022 MODEL: GSS-4PM REV: F 13839 West Bellfort Street, Sugar Land, TX 77498 welker.com Service Department 281.491.2331
3.2 Maintenance

If maintenance on the valves or probe is required, the GSS-4PM must be isolated from pipeline pressure and removed from the
pipeline before maintenance can be safely performed.


Prior to performing maintenance, the GSS-4PM must be isolated from pipeline pressure. However, the GSS-4PM does NOT need
to be removed from the pipeline to perform standard maintenance.

1. Isolate the GSS-4PM from pipeline pressure.

If the GSS-4PM is equipped with a standard probe, close sample pump isolation valve D (Figure 2).
If the GSS-4PM is equipped with the optional LE-2SSKO, close inlet (P₁) valve A and return (P₂) valve B (Figure 3).

2. TurnOFF electrical power to the system and carefully remove all electrical connections.
3. As necessary, disconnect the tubing between the solenoid exhaust and flare.
4. As necessary, disconnect the auxiliary instrument air supply.
5. As necessary, relieve pressure from the tubing connecting the GSS-4PM to the sample cylinder.
6. Remove the GSS-4PM body from the standard probe or from the optional LE-2SSKO.
7. As necessary, maintain the optional LE-2SSKO. Refer to the Installation, Operation, and Maintenance (IOM) Manual for
the LE-2SSKO for maintenance instructions.
8. Unscrew the diaphragm housing from the body, taking care not to misplace the stainless steel Vacuum Breaker™ disc or
clear spider seal, which separate from the body with the removal of the diaphragm housing (Figure 8 or Figure 11). The
collection head assembly should now be exposed.
Figure 8: GSS-4 Composite Sample Pump Diagram