Principle And Application Of Piston Type Flow Regulating Valve

- Mar 25, 2020-

What is a piston type flow regulating valve? What are its characteristics? How does it work? What are the applications? Then the next Jingyi valve will tell us.

Firstly, the characteristics and working principle of piston type flow regulating valve are introduced: RKV and RKV Riko piston type flow regulating valve produced by vag valve company of Germany. Piston type flow regulating valve is different from butterfly valve and gate valve only used for pipeline cut-off. Piston valve can meet various special regulating requirements. Its regulating function is realized by axial movement of a piston like cylinder in the valve chamber, and its stroke is consistent with the flow direction in the pipe. Water flows from the axial arc into the shell, and the flow passage in the piston valve is axisymmetric, so there is no turbulence when the fluid flows through. The change of channel area is realized by a piston moving in a straight line along the axial direction of the pipeline. No matter where the piston is, the water in the valve chamber moves to any position, the water flow section in the valve chamber at any position is ring-shaped, and it shrinks to the axis at the outlet, so as to achieve the best anti cavitation, so as to avoid the possible damage to the valve body and pipeline caused by cavitation caused by throttling. The piston valve body is designed as a whole, with high flow capacity, and the opening is linear with the flow, which can effectively avoid cavitation and vibration. The inner shell is connected with the shell by streamlined guide rib, and the stainless steel piston is reliably guided to slide, so as to avoid inclination or poor operation. The upstream end face of the inner casing is spherical, which makes the water flow form a gradual process. The piston is operated by the crank connecting rod installed in the casing. The piston valve adopts the double sealing of metal to metal and metal to rubber to achieve two-way bubble level sealing. Therefore, the sealing system has a long service life and tight closing. Due to the special structure of the piston valve, according to the different operating conditions, the valve's over water characteristics can be adjusted by the type of outlet components downstream of the valve (the outlet components can be replaced), so as to meet the requirements of different working conditions and achieve the best flow regulation effect.

The second is the application of piston type flow regulating valve. There are four types of outlet regulating parts:


The first type is E-type, which has the structure of straight section and sudden amplification along the downstream cross section of the end seat, so as to eliminate cavitation damage. It is suitable for the situation of flow control, high pressure difference and large back pressure. The structure with straight section and sudden enlargement of cross section can reduce the cavitation effect.

The second type is S-shaped. The closed guide part has a slotted sleeve. It is suitable for controlling the flow, adjusting the high pressure difference and enough large back pressure. Its adjustability matches the fluid state and can achieve better results.

The third type, F-type, has the function of short diffusion tube at the outlet of valve body, which is suitable for regulating and opening / closing occasions and plays the role of switch. The head loss is very small when opening and closing, and the resistance is small when fully opening.

The fourth type, LH or SZ, is equipped with a porous ring net with anti cavitation in the guide part of the piston closed in the valve chamber, which is suitable for regulating, anti cavitation, high pressure difference and small back pressure (at the inlet of the reservoir). Its flow control regulation characteristics and operation conditions require the best matching, so as to eliminate the cavitations effect.

Finally, the vag piston valve can be used as a drain valve and an explosion-proof pipe valve in the aspect of water diversion. During storage, the vag piston valves LH and E can be used as a level or pressure regulating valve. In water delivery, the vag piston valves LH and s can be used as a flow regulating valve, e, LH or SZ can be used as a drain valve or a filling pipe valve. In sewage and water treatment, the vag piston valve can be used as a pump start-up protection valve or equipped with special features The special regulating outlet parts can also be used in the flow regulating valve of the water treatment plant, and the E-type piston valve can also be used as the air volume regulating valve of the sewage treatment plant. In the water supply, the vag piston valve uses different outlet parts as the pressure / flow regulating valve according to the liquid condition.