How to Pre-Charge a Cylinder

1. Connecting the cylinder pre-charge valve to the pipeline (pressurized gas pipeline only):
1. Use small diameter stainless steel tubing to connect from an available pipeline valve to the pre-charge inlet valve. (See Figure 3).
2. Make sure all valves are closed on the sample cylinder.
3. Open the pipeline isolation valve.
4. Slowly open the pre-charge inlet valve.
5. Slowly open the product inlet valve (see Figure 4), to relieve any pressure buildup.
6. The piston will begin to move. Always open valves slowly to avoid slamming the piston from one end to the other.
7. The pre-charge gauge should begin to read pressure and will eventually reach pipeline pressure.
8. Once the piston has reached the end of the cylinder, close all valves and check for leaks.
9. Disconnect the tubing from the cylinder and from the pipeline isolation valve.

2. Connecting the pre-charge valve to the return port on a sampler probe (for continuous sampling of pressurized gas pipeline only):
1. Install a valve into the return port of the sampler probe.
2. Make sure all valves are closed on the sample cylinder.
3. Use small diameter stainless steel tubing to connect from the cylinder’s pre-charge inlet valve (see Figure 3), to the valve on the return port of the probe (not shown).
4. Open the valve on the return port of the sampler probe.
5. Slowly open the pre-charge inlet valve on the sample cylinder (see Figure 3).
6. Slowly open the product inlet valve on the sample cylinder (see Figure 4) to relieve any pressure buildup.
7. The pre-charge gauge should begin to read pressure and will eventually read the pipeline pressure.
8. Leave the pre-charge valve on the sample cylinder open during the sampling procedure.
9. Leave the return port valve on the probe open during the sampling procedure.
10. Check for leaks.

3. Using an auxiliary pre-charge gas:
When using an auxiliary gas, the pre-charge side of the cylinder should be pressurized with a regulated gas supply (i.e., nitrogen or helium) and set 50-100 psi above pipeline operating pressure, not to exceed the maximum allowable pressure of the device.
1. Make sure all valves on the sample cylinder are closed.
2. Use small diameter stainless steel tubing to connect the pre-charge valve to the regulated auxiliary gas supply. (See Figure 3).
3. Open the valve on the gas supply.
4. Slowly open the pre-charge inlet valve on the sample cylinder.
5. Slowly open the product inlet valve on the sample cylinder (see Figure 4) to relieve any pressure buildup. The piston will begin to move.
6. The pre-charge gauge should begin to read pressure and will eventually read the designated pressure.
7. Once the piston has reached the end of the cylinder, and obtained between 50-100 psi, close all valves and check for leaks.
8. Disconnect the tubing from the cylinder and from the pipeline isolation valve