Common valve selection and application you know it

Common valve selection and application

First, the selection of gate valve application is used as a deadline for the media, the entire circulation straight through, the pressure loss of medium operation is minimal. Gate valve is usually applied to do not often need to open and close, and keep the gate fully open or fully closed conditions. Not suitable for use as a regulator or throttling. For high-speed flow media, the gate may cause gate vibration when the gate is open partially, and the vibration may damage the sealing surface of the gate and valve seat, which can cause the gate to suffer erosion of the medium. The main difference from the structural form is the form of the sealing element used. According to the form of the sealing element, the gate valve is often divided into several different types, such as wedge gate valve, parallel gate valve, parallel double gate gate valve, wedge double gate gate and the like. The most common forms are wedge gate valves and parallel gate valves.

Second, the selection of valve applications

Globe valve stem axis and seat sealing surface perpendicular to. Stem opening or closing stroke is relatively short, and has a very reliable cutting action, so that this valve is very suitable as a medium cut off or adjust and throttle use.

Once the valve flap of the globe valve is open, it no longer contacts between the valve seat and the flap sealing face. This valve is ideally suited for cut-off or regulation and throttling of media.

Once the stop valve is open, its valve seat and disc seal surface no longer have contact between, and therefore its sealing surface mechanical wear and tear less, as most of the valve seat and the disc valve is relatively easy to repair or replacement Sealing components without having to remove the entire valve from the pipeline, the door and pipe welding into one of the occasions is very applicable. The flow of medium through the valve changes direction, higher than other valves.

Common cut-off valve are the following:

1) Angular stop valve; in the angular stop valve, the fluid only needs to change direction once, so that the pressure drop through this valve is smaller than that of the conventional structure.

2) DC shut-off valve; In the DC or Y-type shut-off valve, the valve body flow path and the main flow channel into a slash, so that the flow of state damage than the conventional valve is smaller, so the pressure loss through the valve accordingly Small

3) Plunger globe valve: This type of globe valve is a variation of a conventional globe valve. In this valve, the disc and seat are usually designed based on the plunger principle. Polished valve plunger into a plunger connected with the stem, the seal is set by the plunger in the two elastic ring to achieve.

A collar separates and presses the seal around the plunger by a load applied by the bonnet nut on the bonnet.

Made of a wide variety of materials, the valve is primarily used for "on" or "off," but with a special form of plunger or special collar, it can also be used to regulate flow.

Third, the selection of ball valve applications

Ball valve is evolved from the plug valve. It has the same 90 degree rotation action, except that the plug body is a sphere with a circular through hole or passage through its axis. The ratio of the sphere to the port should be such that when the sphere is rotated 90 degrees, the sphere should be fully spherical at the inlet and outlet to cut off the flow.

Ball valve only need to rotate 90 degrees of operation and a small turning moment can be closed tight. The completely equal body cavity provides a medium-sized, straight-through runner with low resistance. Ball valves are generally considered to be the most suitable for direct opening and closing, but recent developments have designed the ball valve to be throttling and controlling flow. The main features of the ball valve is its compact structure, easy operation and maintenance, suitable for water, solvent, so that the valve for the flow of the valve so the resistance of the two elastic ring with acid and natural gas and other general-purpose workers and has a very reliable cut off Elastic sealing ring can be replaced.