Oxygen valve is also called oxygen special valve. It is a special valve specially designed for oxygen pipe network. It is widely used in pipe network of oxygen, steel, metallurgy, petroleum, chemical and other oxygen projects. In addition to the function of ordinary valves, oxygen valves have their own characteristics. From the material selection of the oxygen valve, it is divided into two categories: one is the cast silicon brass for the valve body, the valve cover and the valve disc; the other is the high quality stainless steel for the valve body, the valve cover and the valve flap. Materials. Oxygen is one of the most widely distributed elements in the natural world. According to the volume, the oxygen content in the air is 20.93%. Oxygen is a colorless, transparent, odorless, odorless gas at room temperature and pressure, slightly heavier than air. At atmospheric pressure, when cooled to -182.96 ° C, oxygen condenses into a sky blue, transparent, flowable liquid; when the temperature drops to -218.4 ° C, it condenses into a blue solid crystal. The chemical nature of oxygen is very active. It is a strong oxidant and combustion improver. It can be combined with other substances to form oxides except for gold, silver and inert gases such as lanthanum, cerium, argon and neon. The severity of the oxidation reaction depends on the concentration and pressure of oxygen. If the oxidation reaction is carried out in pure oxygen, the process is very intense and a large amount of heat is released. (If the metal reacts in oxygen, if the purity and pressure of oxygen increase, the oxidation reaction will be significantly increased, the metal ignition point will decrease as the oxygen pressure increases), and oxygen and combustible gas (acetylene, hydrogen, methane, etc.) will be mixed in a certain ratio. In case of fire, an explosion will occur. After the oxygen is compressed, in the process of transportation, if there are grease, iron oxide chips or small particles of combustion (pulverized coal, carbon particles or organic fibers), as the airflow moves and the wall or the organism rubs and collides, it will be generated. A lot of friction heat causes the pipes and machines to burn. Or an explosion is caused by a sudden burning of the valve in the pipe. Based on these special properties of oxygen, pipes, valve fittings, gaskets and all materials in contact with oxygen in the oxygen pipeline must be strictly descaled, purged, and degreased prior to installation. The Vaginal Speculum, is used for gynecology inspection in hospitals and clinics, which is made of medical grade polystyrene.Different types of speculum could be supplied, such as side screw type,fastener type,rack type,Spanish type,middle screw type,big nut type,Screw Fastener Type etc.It is transparent color, which is for disposable use could prevent the cross infection from different painents.The Vaginal Speculums are approved by CE,ISO,FDA certificates, which are popular around the world. Vaginal Speculum Vaginal Speculum,Disposable Vaginal Speculum,Plastic Vaginal Speculum,Medical Vaginal Speculum Hebei Orient Imp. & Exp. Co. Ltd. , https://www.orientmedcare.com
For carbon steel, stainless steel and copper pipes and fittings, industrial carbon tetrachloride should be used. Carbon tetrachloride and dichloroethane are both toxic and must be protected against poisoning. Dichloroethane and distilled alcohol are flammable and explosive substances. Fireworks should be strictly prohibited at the degreasing work site, and the relevant regulations on arson should be observed.
(2) Degreasing test After degreasing, the degreasing quality inspection shall be carried out according to the design regulations. When the design is not specified, the method and qualification criteria for degreasing quality inspection are as follows:
1 Wipe the inner wall of the oxygen valve passage with clean and dry white filter paper. There should be no grease marks on the paper.
2 Irradiation with ultraviolet light, the degreased surface should be free of purple-blue fluorescence.
2 oxygen valve material is made of all stainless steel or all copper base alloy.
3 Oxygen valve sealing packing should be made of Teflon.
4 The flange on the oxygen pipeline shall be selected according to the relevant national JB standards.
5 The flange gasket on the oxygen pipeline should be annealed and softened aluminum sheet, and the copper sheet is annealed and softened.
2 The oxygen pipeline should have a grounding device that removes static electricity. The plant pipeline can be equipped with a grounding device at every 80-100m of the branch-free branch and at the entrance and exit of the workshop. The directly buried pipelines can be grounded before and after the grounding; the internal pipelines of the workshop can be connected with the static trunks of the workshop, and the grounding resistance should meet the specifications. When the resistance value between each pair of flanges or threaded joints exceeds 0.03 Ω, a jumper wire should be provided. Pipes with negative protection should not be grounded.
3 The elbow and bifurcation head of the oxygen pipeline shall not be installed immediately downstream of the valve, and the downstream side of the valve shall be provided with a straight pipe section with a length not less than 5 times the outer diameter of the pipe.
2 Oxygen valves, fittings and gaskets must be degreased, degreased in the manufacturing plant, and have a reliable sealed package that can no longer be degreased.
3 Pipes, valves, pipe fittings, etc. should be taken during the installation process and after installation to prevent contamination by the oil.
2 flange connection size conforms to GB9115
3 structure length according to GB12221
4 degreasing and inspection according to HGJ202
5 test and inspection according to GB/T13927
6 materials meet GB12225, GB12230
Remarks: The above requirements for oxygen valves also apply to acetylene and hydrogen.
Introduction to oxygen valve
Pipe degreasing
(1) Degreaser Industrial carbon tetrachloride, rectified alcohol and industrial dichloroethane can be used as a solvent for the degreaser.
Selection of special valves for oxygen
1 For valves with working pressure greater than 0.1 MPa, gate valves are strictly prohibited, and globe valves or ball valves should be used.
Oxygen special valve connection
1 The connection of the oxygen pipeline should be welded, but the connection with equipment and valves can be flanged and threaded. For threaded connecting pieces, lead oxide, water glass or Teflon film should be used as the filler. It is strictly forbidden to use linen or cotton wire for lead coating or other materials containing grease.
Acceptance of oxygen-specific valves
1 Oxygen valves, pipes and fittings, etc., shall be free of cracks, scales, slag inclusions, etc. The surface exposed to oxygen must be completely removed from burrs, welds, welding slag, sand, rust and other combustibles, keeping the inner wall smooth and clean, and the rust removal of the pipes should be carried out until the original color appears.
Standard for oxygen-specific valves
1 design and manufacture according to GB12237, GB12235