Valving Procedures

Catalina Cylinders recommends the following procedure for the valving of industrial gas cylinders.

    1. Inspect the inlet and outlet threads of the valve and the threads and o-ring gland of the cylinder for damage to the threads and o-ring area. If either the valve or cylinder has damage to the threads or the o-ring area, do not insert the valve into the cylinder.
    1. Inspect the cylinder threads and the cylinder internally verifying that the cylinder is free from any lubricants and contaminants. Do not proceed if you feel the cylinder may be contaminated.
    1. Catalina Cylinders recommends the insertion of a new buna-N o-ring when the old o-ring shows any sign of tearing or wear.
Cylinder ThreadDesignation ValveDesignation Buna-N
O-ring Size
1.125 – 12 UNF CGA 580 216


    1. Catalina Cylinders has found it easiest to place the o-ring on the valve and then insert the valve into the cylinder tightening the valve hand tight.
    1. Final tightening of the valve should be done with a calibrated torque wrench to the recommended torque value noted below:
Catalina Cylinders
Thread Designation Recommended Torque Maximum Torque
1.125 – 12 UNF 40 lbf – ft 50 lbf – ft
.750 – 16 UNF 40 lbf – ft 50 lbf – ft


    1. Close the valve with no more than 1 lbf – ft torque.
    1. Do not tamper with the safety device of the valve. The safety device of the valve should be rated at the test pressure of the cylinder.
    1. Whenever replacing the safety device of a valve, Catalina Cylinders recommends that you always replace the safety device with a complete new safety device assembly.
  1. Always verify that the cylinder is empty prior to attempting to replace the safety device of a valve.

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