Oxygen service regulators

What happened?

It was discovered on several dive sites that regulators being used on high pressure gas quads of greater than 25% oxygen were not actually suitable for oxygen service.  Component parts of an oxygen system are said to be fit for oxygen service when they are both:

• Oxygen clean;
• Constructed from components with high temperature resistance.

While the items had been delivered oxygen clean to the proper specification, some of the component materials were found not to be oxygen compatible.  Additionally, the regulator type supplied was a venting model, whereas a non-venting model was recommended.

What was the cause?

Product knowledge was insufficient/incomplete on the part the buyer at the time of purchase.

What actions were taken?  What lessons were learned?

A thorough reading of specifications should be made before selection of a product.  The understanding that the regulators were delivered clean for Oâ‚‚ service convinced the end users that they were suitable.

The certificate which the supplier includes separately, if requested and at additional cost, states:

“Note: Specifications of materials in regulators for Oxygen Service is the USER’S RESPONSIBILITY.”

Our member has performed a management of change (MoC) procedure for the change-out of all affected company regulators (on quads and in dive panels).  A risk assessment was performed, and the results indicated the need to retrofit fully compliant oxygen service regulators that are not only oxygen clean, but also constructed of oxygen compatible materials.  However, it was considered that there were enough mitigations in place to retain the use of the venting model for select purposes such as gas quads in designated no hot work areas on open decks.

Over the course of the transition, company personnel and suppliers are being informed about the change and the reasons for it.

IMCA members are advised to ensure that all regulators or other components intended for use within oxygen systems are fit for oxygen service, i.e. that they are oxygen clean and made from oxygen compatible material.