Soft and hard seal are able to complement each other. The seal ability of soft one is better than hard one, however, hard seal now can also meet some requirements. Soft seal has better sealing ability, but can easily age, wear and has a short lifespan. Hard seal can be used longer, but has poorer sealing ability. Characters of Soft Seal Valves Soft seal: one side of the seal is metal, while another the other side is elastic nonmetallic materials. This is “soft seal”. It has great sealing...

The materials and the quality of gas valves are so important that their disqualification will lead to leakage in-or-outside the body of the valve. If the strength, rigidity and overall performance of the components of the valve body cannot meet the requirements or even break, it will result in the spillage of gas and explosion. Therefore, material and quality are the most critical part during the process of developing, designing, and studying gas valves. How to choose materials for Gas Valves:...

Butterfly valves, also called as flap valves, are a kind of valves having simple structure. Butterfly valves can also be used for low pressure pipelines to regulate media. The disc of butterfly valves is a plate, swinging with valve shaft to turn on or off valves. Butterfly valves are used for cutting off and throttling in pipelines. Industrial specialized butterfly valves have high temperature resistance and wide applicable pressure range. They have large nominal diameter. The body is made of carbon...

Based on structure, ball valves are classified into following types: 1. Floating ball valves The ball of floating ball valves is floating. Under the pressure of medium, the ball can displace and compress on the sealing face of exit to ensure the sealing of exit. Floating ball valves have simple structure and good sealing. However, load of medium bear by ball is transmitted to sealing ring of exit completely. For that, materials of sealing ring must endure the load of medium. Floating...

Characteristics of vent butterfly valve 1. The structure of vent butterfly valve is welded by center line disc and short steel plate, having compact structure, light weight, convenience for installation, small flow resistance, high flow capacity. It is not affected by high temperature expansion. 2. Vent butterfly valve does not have connecting rod or bolts, having reliability, long service life. It can be installed at any positions without limitation of medium flow direction. Principles of...

Currently, a large amount of large desalination projects are being built in China. Valves are used as key devices for desalination project. Chloride may corrode equipments during desalination. Temperature of sea water has great influence on velocity of corrosion. The higher temperature is, the faster corrosion is. Otherwise, solid contaminants can also damage protective film of materials, resulting in erosion corrosion. Other chemical contaminants also increase corrosion probability. Ingredient...

Three-way ball valve utilizes ball as its closure member. The ball rotates with center line of body to open or close valve. Characteristics of three-way ball valve 1. Open or close without friction The structure does not have the disadvantages that sealing faces of conventional valve rub with each other, effecting sealing. 2. Jacket structure The valve having been installed at pipes can be checked and maintained on-line directly, reducing plant stop and cost effectively. The valve is installed...

Most of butterfly valves can be used for medium containing suspended solid pellets for disc moving with wipe. According to strength of sealing face, butterfly valves are also used for powdery or grainy medium. Butterfly valves have low face to face dimension and overall height, opened or closed rapidly and low fluid resistance. When opening angle is between 15 degree and 70 degree, butterfly valves can control flow sensitively. The structure of butterfly valves is quite suitable for large caliber...

Pneumatic ball valves use a ball with a hole as open-close part. The ball rotates with axis which is vertical to channel so that it can open or close valve. Pneumatic ball valves are used to connect or cut off medium inside pipes. Advantages of pneumatic ball valves: 1. Pneumatic ball vales are suitable for operating usually. Open or close rapidly. Having portability. 2. Having low fluid resistance. 3. Having simple structure, low volume, light weight, convenient for maintenance. 4. Having...

Structure of welded ball valve: 1. Welded ball valve is made of carbon steel seamless steel tube which is pressed into intergrated welded ball valve. 2. Stem is made of AISI303 stainless steel. Body is made of AISI304 stainless steel which has been grinded finely, having good seal and corrosion resistance. 3. Seal ring adopts carbon strengthened PTFE cant elastic seal ring. The seal ring is pressed on ball to realize zero leakage and enhance service life. 4. Face to face: welded end, screw end,...

Common valves in water system of heating air condition include gate valve, globe valve and butterfly valve. Gate valve For its moderate length, rotary adjusting rod and good regulating performance, gate valve is widely utilized in large caliber pipes. Globe valve Globe valve is suitable for small caliber pipes for its long length, rotary adjusting rod and good regulating performance (DN≤150mm). Butterfly valve Butterfly valve has short length, handle regulating rod,...

Based on structure, stainless steel butterfly valve can be classified into offset plate butterfly valve, vertical plate butterfly valve, cantboard butterfly valve, lever butterfly valve. Based on seal, stainless steel butterfly valve is classified into soft seal butterfly valve and hard seal butterfly valve. Soft seal butterfly valve uses rubber seal ring. Hard seal butterfly valve uses metal seal ring. Based on connection, stainless steel butterfly valve is classified into flanged butterfly valve...