Valve Cleaning and Degreasing Procedures for Oxygen Service

ted wang
Jun 4
2 min read

Why Oxygen Service Requires Special Cleaning

Oxygen-enriched or high-purity oxygen service creates extreme fire and explosion hazards if organic contaminants are present inside valves and piping. Hydrocarbons, grease, oil, and even dust particles can ignite spontaneously when exposed to oxygen at elevated pressures or velocities. Strict cleaning and degreasing procedures are mandatory before valves are placed into oxygen service.

Applicable Standards

ASTM G93: standard practice for cleaning methods and cleanliness levels for oxygen systems
CGA G-4.1: cleaning equipment for oxygen service
IGC Doc 33: European industrial gas cleaning standard for oxygen service
EIGA IGC 33: cleaning of equipment for oxygen service
Valve manufacturer procedures: typically reference ASTM G93 Level A or equivalent

Cleaning Process Steps

Oxygen cleaning involves mechanical cleaning (brushing, flushing), solvent degreasing, aqueous detergent cleaning, rinsing, drying, and final inspection. Solvents must be compatible with the materials being cleaned and must be completely removed from the valve after use. Common solvents include acetone, isopropyl alcohol (IPA), and specialized oxygen-compatible degreasers.

Inspection and Verification

Visual inspection under white light to detect visible contamination or particulate
UV light inspection to detect organic residues not visible under normal light
Solvent wipe test: white cloth wiped on internal surfaces examined for contamination
Particle count and size analysis for ultra-clean oxygen service
Documentation: cleaning record, cleanliness level achieved, and inspector sign-off

Packaging and Handling After Cleaning

Cleaned valves must be immediately purged with dry oil-free nitrogen and sealed in clean polyethylene bags or cleanroom packaging. Cap all ports. Label with oxygen-clean status. Personnel handling cleaned valves must use clean cotton or nitrile gloves. Any damage to packaging or evidence of contamination requires re-cleaning before installation. Stores segregate oxygen-clean components to prevent contamination.