1、Bottle valve closed state air leakage

Bottle valve closed state air leakage is generally the core of the valve core damage or fuse piece broken or poor location， sealing is not good， replace the valve core or fuse piece can be ruled out. This kind of air leakage is generally handled before the product leaves the factory， users such as occasionally encounter this phenomenon， take back to the production plant can be replaced.

2， bottle valve open state air leakage

Users often encounter the problem of air leakage after the valve has been opened. Bottle valve open after the leakage， refers to the use of the process， the bottle valve unscrewed after the oxygen in addition to flow down the pipeline to the hands of the master worker welding， cutting torch， or down the pipeline for the patient to breathe， there is a part of the oxygen from the gap around the bottle valve stem upward leakage. This phenomenon is difficult to deal with and requires both knowledge of the internal structure of the bottle valve and the performance of the sealing material， as well as certain skills and techniques. This is why the user cannot handle it without permission. This article focuses on the treatment and prevention of air leaks in the open state of the bottle valve.

The treatment and prevention of air leakage in the open state of the cylinder valve:

China's medical oxygen cylinder valve is "medical oxygen cylinder valve" the technical requirements of the production. There are several professional production plants in China. According to the relevant provisions of GB10877， the medical oxygen cylinder valve "in 1.1 times the nominal pressure， the cylinder valve in the closed and arbitrary open state should not leak". Closed and open at will without leakage， commonly known as the lower seal and upper seal. The lower seal (no leakage in the closed state) is made by the spool and the upper seal (no leakage in the open state) is made by the gasket set on the stem. In the case of the gasket intact， the valve is fully open (open all) can ensure that no leakage， but the user can not use the full open， just unscrew a small point， it is difficult to ensure that no gas leakage.

Talk about how to avoid leaking medical oxygen cylinders

In order to prevent this phenomenon， some cylinder valve manufacturers have opened an annular groove in the through hole of the large pressure cap of the cylinder valve and installed an O-shaped sealing ring to reduce the probability of air leakage.

The problem of leaking cylinders is dealt with by the periodic cylinder inspection station attached to the gas production plant (hereinafter referred to as the "cylinder inspection station"). Many gas cylinder inspection stations assume that the O-ring is a flammable material and discard it from the annular groove of the large pressure cap， which is very wrong. There are three sealing materials on a cylinder valve， namely the core， the gasket and the O-ring. They are located in different locations and are exposed to different purity of oxygen， so their non-combustible properties are required differently. The core is in contact with the 15Mpa pure oxygen in the bottle， the highest non-combustible performance requirements， is made of tetrafluoroethylene plus copper powder filler， difficult to oxidise， not burning， put it on the open fire can not burn; gasket set on the stem， above the core， contact with the oxygen from the threads of the bottle core leak up， the pressure has been reduced， the oxygen purity is also reduced， the non-combustible performance requirements of its material is correspondingly reduced some. Generally made of nylon-6 or polyethylene; O-shaped seal ring on top of the gasket， oxygen pressure is lower， the requirements for non-combustibility of the material is lower， generally with flame retardant rubber can be.

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