You wouldn't grab a standard ball valve off the van for an oxygen line, but it's easy to see why someone might. It's the same size, thread and pressure rating, and it looks identical.
The difference is inside. Most standard valves are assembled with hydrocarbon grease on the seats and stem, and in a high-pressure oxygen line that grease is a fire hazard.
Oxygen service needs valves that have been cleaned to remove those contaminants and assembled without grease. Zetco's new range includes an oxygen-cleaned ball valve and spring check valve built for that job.
Why Grease and Oxygen Don't Mix
Oils and greases that are harmless on water or air can ignite in an oxygen-enriched atmosphere. Compression heating when a valve opens quickly can be enough to start it, and so can particle impact.
Once it starts, an oxygen fire can consume metal components. That's why oxygen systems are cleaned and kept clean from the factory to the commissioning test.
An oxygen cleaned, ungreased valve has had its oils, grease and particulates removed. It's assembled without hydrocarbon lubricants and packed to stay that way until you fit it.
Oxy-Cleaned Brass Ball Valve: Series 2701
The Zetco 2701 oxygen ungreased ball valve is the isolation valve for oxygen and medical gas lines.
- Full brass body, PTFE seats
- Oxygen cleaned and ungreased
- Rated 2000 kPa, -20°C to 60°C
- 10–100mm female BSP. The 100mm comes with a lockable handle.
Zetco pitches it at hospitals, clinics, dental surgeries and labs. That covers zone isolation, plant room isolation and branch isolation on oxygen and other oxidising gas services.
Oxy-Cleaned Spring Check Valve: Series 2927
The Zetco 2927 oxygen ungreased spring check valve is a Eurostop spring check in DZR brass, oxygen cleaned and ungreased.
- Rated 2000 kPa, -20°C to 60°C
- 15–50mm female BSP
Use it where you need to stop reverse flow on an oxygen or medical gas line. Typical spots are manifold and cylinder bank connections, or anywhere two supplies meet and one mustn't back-feed the other.
Standards and Who Does the Work
Medical gas pipeline systems in Australia are designed and installed to AS 2896. Depending on your state, the work may need specific licensing or endorsement beyond general plumbing or gasfitting.
The project's medical gas specification usually controls which components are accepted. Before you order, check that:
- The spec accepts the valve type and material
- The pressure rating covers the system, including any high-pressure section before a regulator
- Your licence covers the work
Zetco lists both valves as not WaterMarked. They're for gas service, not water.
Handling on Site: Don't Undo the Cleaning
An oxy-cleaned valve is only as clean as the last pair of hands that touched it.
- Keep it bagged and capped until it's going in.
- Clean gloves, with no grease, oil or hand cream.
- Use only oxygen-compatible thread sealant. Standard pastes and many tapes aren't suitable for oxygen.
- Don't lubricate it, ever. If it's stiff, it's built that way.
- Purge and test the system as the medical gas spec requires before handover.
- Open oxygen valves slowly. Snapping a valve open on high-pressure oxygen causes compression heating, which is exactly what you're trying to avoid.
Stainless Options
Zetco also makes 2-piece stainless oxygen-cleaned ball valves in F&F and M&F. They're not yet available to order online. If a spec calls for stainless on an oxygen line, contact PSA and we'll check availability.
The Short Version
Never put a standard greased valve on oxygen. Use an oxygen cleaned, ungreased valve: the 2701 ball valve for isolation and the 2927 spring check where reverse flow has to be stopped.
Keep them clean through the install and confirm the spec and your licence cover the job.
Both are in our Zetco collection, and the check valve is also in check valves. For more on check valve types, see spring vs swing check valves.
Frequently Asked Questions
What does oxygen cleaned and ungreased mean?
The valve has been cleaned to remove oils, grease and particulates, and assembled without hydrocarbon lubricants. Those contaminants can ignite in an oxygen-enriched atmosphere.
Can I use a standard ball valve on an oxygen line?
No. Standard valves are typically assembled with grease, which is a fire risk in oxygen service. Use a valve supplied oxygen cleaned and ungreased, such as Zetco's 2701.
What thread sealant should I use on oxygen fittings?
Only a sealant specifically rated as oxygen compatible. Standard thread pastes and many general-purpose tapes aren't suitable. Follow the project's medical gas specification.
What standard covers medical gas pipelines in Australia?
Medical gas pipeline systems are designed and installed to AS 2896. Check your state's licensing requirements for the work and confirm the project spec accepts the components.