Maintenance Plan For Stainless Steel Ball Valves And What Seals To Choose For Environmental Conditions

Customers should learn the maintenance operation of 2 Piece Threaded Ball Valve when using stainless steel ball valves for a long time.

Stainless steel ball valve is a commonly used valve instrument, which is mainly used to cut off, distribute and change the flow direction of the medium. It has the advantages of simple structure, small size, light weight, small fluid resistance and convenient maintenance. Stainless steel ball valves need certain maintenance during use to ensure the normal operation of stainless steel ball valves. So how to maintain stainless steel ball valves? Today, the editor will introduce the maintenance methods of stainless steel ball valves in detail.

Maintenance operation of stainless steel ball valves:

First: After the rough product is finished and pickled, it must be rinsed clean. If there are sand holes or perforations, it should be welded with gas shielded argon arc welding. Then grind it and then perform solid solution treatment;

Second: After the finished product, the processing and pressure test are completed. It should be rinsed with water added with rust-proof powder.

Third: Try to use wooden box packaging during transportation and do not contact metal products.

Fourth: After installing the pipeline, regularly maintain and maintain it, such as frequently applying lubricating oil to the valve stem. Open and close the valve several times appropriately. The inner ball, valve stem and sealing surface are not easy to assimilate.

Stainless steel ball valves generally have two structures: reduced diameter and non-reduced diameter channel. Regardless of the structure, the flow resistance coefficient of the ball valve is relatively small.

In particular, the so-called full-flow type, that is, the non-reduced diameter ball valve, because its channel diameter is equal to the inner diameter of the pipeline, the local resistance loss is only the friction resistance of the pipeline of the same length, that is, among all valves, this type of ball valve has the smallest flow resistance. In rocket launch and its test system, the resistance of the delivery pipeline is required to be as small as possible.

There are two ways to reduce the resistance of the pipeline system: one is to reduce the fluid flow rate, for which it is necessary to increase the pipe diameter and valve diameter, which often has an adverse effect on the economy of the pipeline system, especially for low-temperature delivery systems (liquid hydrogen).

(1) Reduce the local resistance of the valve, so the ball valve naturally becomes the best choice.

(2) The ball valve is quick and convenient to open and close.

Since the ball valve can be fully opened or closed by turning the handle 90° under normal circumstances, it is easy to achieve rapid opening and closing. It can realize fast opening and closing. The opening and closing time of some structures is only 0.05-0.1s, so as to ensure that it can be used in the automation system of the test bench. When the valve is opened and closed quickly, the operation is impact-free.

(3) The ball valve has good sealing performance.

The valve seat of most ball valves is made of elastic materials such as polytetrafluoroethylene. The sealing pair composed of metal and non-metallic materials is usually called soft seal. Generally speaking, the sealing performance of soft seal is easy to ensure, and the processing accuracy and surface roughness requirements of the sealing surface are not very high.

(4) The service life of the ball valve is long.

Because polytetrafluoroethylene has good self-lubrication, the friction and wear with the ball is small, and the improvement of the ball processing technology reduces the roughness, thereby increasing the service life of the ball valve.

The soft seal form of the stainless steel ball valve has a leakage level of VI, and the hard seal leakage level is IV. Usually, when the pipeline is water medium and there is no normal temperature, a soft seal ball valve should be selected. If the environment is harsh and the medium in the pipeline is high temperature or a mixture with particles, a hard seal ball valve must be selected.