Imagine everything is ready to start up an oxygen line, but the valve supplier warns: “You need a degreased valve according to ASTM G93.”
Or a customer from the automotive sector insists: “Valves must be certified silicone-free.”
And then the questions begin. What does that mean? What are the risks? How is this done? In this article, we break down what these special specifications mean and why they are essential in sensitive applications.
What Is a Degreased Valve?
A degreased valve is one that has undergone a special cleaning process to remove all traces of oils, greases, hydrocarbons, silicone or other contaminants that may remain after manufacturing, assembly or handling.
This is critical when valves are used in systems carrying highly reactive, oxidizing or high-purity gases, such as:
- Oxygen (O2)
- Chlorine
- Helium, nitrogen and argon in high-purity service
- Hydrogen
- Cryogenic mixtures
Why is this essential for oxygen? Even the smallest trace of grease can react violently with pure oxygen, causing explosions, internal fires or severe leaks. Degreasing helps ensure the valve does not become an ignition point.
Typical Fluids and Industries Requiring Degreased Valves
Degreasing requirements are common wherever cleanliness, oxidizer compatibility or product purity are part of the safety case.
| Industry | Common fluid or use | Degreasing requirement |
|---|---|---|
| Industrial gases | Oxygen, helium, nitrogen | Yes |
| Cryogenics | Liquids at -150°C or below | Yes |
| Medical | Hospital-grade oxygen | Yes |
| Food and beverage | CO2, nitrogen | Sometimes |
| Pharmaceutical | Clean steam or filtered air | Depends on specification |
| Chemical | Chlorine, peroxides | Yes |
How Are Valves Degreased?
Degreasing is not just a rinse. It is a technical and traceable process designed to remove residues without introducing new contamination.
Typical cleaning methods
- Solvent cleaning with residue-free agents
- Ultrasonic baths with special detergents
- Dry steam cleaning in controlled cabinets
- Final nitrogen purge and sealed packaging
Standards of reference
- ASTM G93, with cleanliness levels depending on the required service
- CGA G-4.1 for oxygen service
- ISO 15001 for medical gases
After cleaning, inspection methods such as UV inspection or a white cloth test may be performed. A cleaning certificate should identify the method, lot number and traceability data.
What Are Silicone-Free Valves?
Another lesser-known, but equally important, requirement is for silicone-free valves. This refers to valves manufactured, assembled and packaged without contact with silicone-based materials, including silicone greases, silicone lubricants, silicone-containing sealants, contaminated gloves, gaskets or cleaning cloths.
Why avoid silicone? In industries that require high-precision painting, coating or adhesive bonding, even microscopic silicone contamination can cause paint cratering, fisheyes or product rejection.
| Application | Main risk | Typical requirement |
|---|---|---|
| Automotive painting | Fisheyes and coating defects | Silicone-free certification |
| Aerospace coating | Adhesion failure or surface defects | Controlled assembly and packaging |
| Industrial varnishes | Surface rejection or rework | Silicone-free components and handling |
| Electronics and PCB production | Contamination affecting bonding or finishing | Dedicated clean handling |
How Is Silicone-Free Certification Ensured?
- Selection of silicone-free lubricants and components
- Assembly in isolated or clean areas
- Use of inert materials such as PTFE or graphite where suitable
- Dedicated packaging and labeling
- Certificate of silicone-free compliance upon request
As with degreasing, it is not enough to say it. The requirement must be proven, documented and protected during storage and handling.
Quick Checklist: Do You Need These Specs?
| Question | Recommended action |
|---|---|
| Is the valve used with oxygen or high-purity gases? | Request degreasing |
| Is there a risk of hydrocarbon reactivity? | Request degreasing |
| Is it part of a paint, coating or adhesive process? | Request silicone-free execution |
| Do project specifications reference ASTM G93 or CGA G-4.1? | Request cleaning documentation |
| Is the customer in automotive or aerospace? | Ask for technical validation before procurement |
Final Thought: What You Do Not See Also Matters
In valve selection, what you do not see can be the real problem. Good design and suitable materials are not enough if final cleaning compromises safety or product quality.
Whether the objective is to avoid ignition risks in oxygen service or to prevent coating defects in automotive paint lines, special cleaning processes are critical to valve performance.
Not sure if your valve needs degreasing or silicone-free certification? Contact EFSVALVES and we will guide you through the specification, cleaning, documentation and packaging requirements.
