Page 2 of Technical Articles

(2) Semi-forced seal: Valves which have the characteristic of semi-forced seal are mainly trunnion mounted ball valves and non-mechanically balanced plug valves. These valves have the characteristic that the sealing pressure between the valve clacks and the valve seats is preset and is generated or...

The shut-off seals of valves can be divided into three categories: forced seal, semi-forced seal and passive seal. A. Forced seal: The sealing pressure of forced seal can be increased by the further rotation of hand wheels. B. Semi-forced seal: The sealing pressure of semi-forced seal is generated by...

When we use and check safety valves, breakdowns always happen, which are mainly caused by the improper design, manufacturing, selection or use. If these faults are not promptly cleared, they will affect functions and service lives of safety valves. Common breakdowns and solutions are as follows: 1....

Leakages beyond nominal range occuring in the parts between safety valve clacks and seats which should be sealed will result in losses of media and damage of sealing materials. Generally, sealing surfaces of safety valves are made of metal materials and are made to be smooth and even. However, it is...

Cryogenic valves refer to valves applicable to the medium temperature between -40 ℃ and -196 ℃. The cryogenic valve includes the cryogenic ball valve, cryogenic gate valve, cryogenic globe valve, cryogenic safety valve, cryogenic check valve, cryogenic butterfly valve, cryogenic needle valve, cryogenic...

When pneumatic diaphragm control valves are running, there will be various kinds of process medium flow through the automatic valve, including the large blocks of raw materials, sand, stones, iron scales and iron sheets washed over by steam, and the slags cut off into the pipe in the process of instruments...

In the contemporary industry, pinch valves are the best option for transporting solid or liquid products containing abrasive substances such as particle, powder, fiber, sticky pulp, or some corrosive mediums in the chemical process. Austrian liner pinch valves are applied to sewage treatment plant (sludge...

Low temperature regulating valve installation tips: Check if the valve parts are damaged or loose. Those mediums which are harmful for human health must have intensity, sealing, leakage and accuracy tests. Clean pipes and valves, remove impurities and oil before installing. The user can make specific...

In the design of valves, the valve filler of lift valves are asbestos packing, grafoil and V type PTFE. But these filler are limited by the times of opening and closing of valves. With the increasing of opening and closing times, the filler will be weared and the gap will increase. The valve will leak...