◆ The oxygen check valve is made of silicon brass or stainless steel with excellent material, which has the advantages of high mechanical strength, wear resistance, and good safety. Used on the oxygen pipeline, it has good anti-explosion and flame retardant performance, eliminating the unsafe factors on the oxygen pipeline. It is composed of valve body, valve cover, valve plate, etc. The medium enters from one end to raise the valve plate and the medium circulates; when the medium pressure disappears or the outlet pressure is greater than the inlet pressure, the valve plate automatically drops to close the passage and play a non-return function. The main parts of the valve are made of silicon brass, which has good fire resistance.

Design Feature+

◆ Cleanliness check

Inner surfaces shall be subject to a qualitative cleanliness spot check. Check shall be done by one of the following test methods which are suitable for the valve type concerned:

a)Visual examination under bright light and "black light" (= ultraviolet light 320 nm to 370 nm)

b)Wipe test with white, lint-free cloth or filter paper; aided by ultraviolet light

c)Solvent flushing test / weight determination of residue after evaporation

d)All valves shall bear a visible marking (tag fixed at the valve) as follows:"Free of oil and grease"

◆ Preservation of cleanliness

e)Valves shall be protected against contamination or moisture by closure of openings, e.g. with degreased plastic caps. Valves shall be packed individually, e.g. in a clean polyethylene tube or bag.

f)The preservation packing shall bear a well visible marking (tagged or printed):"Free of oil and grease"

g)For carbon steel valves, the interior of the sealed bag shall be equipped with desiccants. The number of desiccant bags used shall be indicated appropriately on the preservation packing.

◆ Documentation and certification

Manufacturer shall provide the following documentation:

Handling and storage instructions for valves

Cleanliness check report per delivery lot showing the results of the performed cleanliness checks

Cleaning and preservation methods

◆ Cleaning methods described are recommended as "best practices" which lead to the required cleanliness level.

◆ ASTM G93 or MSS SP138 may also be used to define a suitable cleaning procedure.

◆ Surface cleaning from foreign substances

1)Blowing with oil free air is recommended to remove loose foreign particles.

2)Blasting or pickling might be used to remove foreign substances from surfaces (rust, scale etc.).

3) Cleaning / degreasing with organic fluids :Organic cleaning fluids are unacceptable for cleaning and degreasing metallic surfaces.

◆ Cleaning / degreasing with aqueous fluids

Aqueous cleaning fluids with tensides are suitable for cleaning and degreasing metallic surfaces. The following aspects shall be considered in case of usage:

1)Each component shall be cleaned prior to assembly

2)The cleaning fluid shall not corrode the materials to be cleaned.

3)The cleaning effect strongly depends on tenside concentration, temperature and mechanical movement (use of ultrasonics, concentrated jets etc.).

4)Bath cleaning fluids shall be regenerated in time.

5)The cleaned surfaces shall be carefully rinsed with deionized water to remove all tenside residues.

◆ Preservation of cleanliness

Design Standard+

◆ Design: API600 / ASME B16.34 / API602 / BS5352 / API 594 / BS 1868

◆ Face to face: API6D / ASME16.10/ ISO5752

◆ Flange end: ASME B16.5 / ASME B16.47 / EN1092-2 / GOST 12815 / MSS-SP44

◆ Socket welded end: ANSI B16.11

◆ Screw end: ANSI B1.20.1