Peter Barnes, LLNL
Version 0.1
October 19, 2001

E907 TPC Bottle Change Procedure

NOTE: This procedure MUST be used when changing P10 AND nitrogen bottles in the E907 TPC cylinder rack.

When a cylinder is changed, the high-pressure line connected to the cylinder valve is exposed to oxygen in the air. This procedure ensures that the line is purged properly, preventing the introduction of oxygen into the flammable gas system.

When Does a Cylinder Need to Be Changed?

Both the nitrogen and P10 sides operate with dual supply manifolds. The main supply regulators (PRV-01 and PRV-03, for P10 and nitrogen, respectively) are set at 15 psi, higher than the reserve supply regulators (PRV-02 and PRV-04). The output pressure meters on both the main and reserve regulators will indicate this pressure. When the main supply cylinders run out, the pressure will drop to the reserve supply regulator setting, 10 psi. At this point the main supply cylinders need to be replaced.

Cylinder Change Procedure

The cylinder change procedure is given in the table below. Change one set of cylinders at a time, using the valves indicated in the appropriate column.

Step

Action

P10 Valves

Nitrogen Valves

Main

Reserve

Main

Reserve

1.

Close the main supply cylinder valves.

MV-01 MV-02

MV-04

MV-07 MV-08

MV-10 MV-11

2.

Switch the main supply outlet to the vent line. This will vent the high-pressure gas remaining in the supply manifold.

MV-03

MV-05

MV-09

MV-12

3.

Wait for the high-pressure gage on the regulator to drop to zero.

PRV-01

PRV-02

PRV-03

PRV-04

4.

Disconnect the flex lines from the cylinders at the main cylinder valves.

MV-01 MV-02

MV-04

MV-07 MV-08

MV-10 MV-11

5.

Remove the empty cylinders and replace with full cylinders.

6.

Connect the flex lines removed in Step 4.

MV-01 MV-02

MV-04

MV-07 MV-08

MV-10 MV-11

7.

Open the the main supply cylinder valves. Gas will flow through the supply regulator to the vent line. This will allow the air, introduced to the high-pressure manifold in Step 4-6, to be purged from the system.

MV-01 MV-02

MV-04

MV-07 MV-08

MV-10 MV-11

8.

After xx seconds, switch the main supply outlet back to the system.

MV-03

MV-05

MV-09

MV-12

Step	Action	P10 Valves	Nitrogen Valves
Main	Reserve	Main	Reserve
1.	Close the main supply cylinder valves.	`MV-01 MV-02`	`MV-04`	`MV-07 MV-08`	`MV-10 MV-11`
2.	Switch the main supply outlet to the vent line. This will vent the high-pressure gas remaining in the supply manifold.	`MV-03`	`MV-05`	`MV-09`	`MV-12`
3.	Wait for the high-pressure gage on the regulator to drop to zero.	`PRV-01`	`PRV-02`	`PRV-03`	`PRV-04`
4.	Disconnect the flex lines from the cylinders at the main cylinder valves.	`MV-01 MV-02`	`MV-04`	`MV-07 MV-08`	`MV-10 MV-11`
5.	Remove the empty cylinders and replace with full cylinders.
6.	Connect the flex lines removed in Step 4.	`MV-01 MV-02`	`MV-04`	`MV-07 MV-08`	`MV-10 MV-11`
7.	Open the the main supply cylinder valves. Gas will flow through the supply regulator to the vent line. This will allow the air, introduced to the high-pressure manifold in Step 4-6, to be purged from the system.	`MV-01 MV-02`	`MV-04`	`MV-07 MV-08`	`MV-10 MV-11`
8.	After xx seconds, switch the main supply outlet back to the system.	`MV-03`	`MV-05`	`MV-09`	`MV-12`

Swapping Main and Reserve Functions

When the reserve supply cylinders are getting low, they the main and reserve functions may be swapped temporarily. This is accomplished by lowering the main supply regulator (PRV-01 and PRV-03, for P10 and nitrogen, respectively) setting to 10 psi and raising the reserve supply regulator (PRV-02 and PRV-04, for P10 and nitrogen, respectively) setting to 15 psi.