Piston control valve, as an improved product of needle valve, has long been active in long water delivery, DAMS and hydropower stations. Piston control valve is an energy dissipation valve with reasonable design, simple operation, low maintenance rate and economical and effective.

Piston control valve is mainly composed of body, seat, piston, valve shaft, crank, connecting rod, drive pin, taper pin, bearing and operating mechanism. The piston-type control valve converts the rotation of the valve shaft to the axial movement of the piston along the guide rail through the crank connecting rod mechanism. In the process of the piston moving back and forth, the flow area between the piston and the seat is changed to achieve flow regulation and pressure control.

The flow from the axial arc into the valve body, piston control valve for the flow of axisymmetric shape, fluid flow will not produce turbulence. No matter the piston moves to any position, no matter what position of the flow in the valve cavity are annular, in the exit to the axis contraction, so as to achieve zUI good anti-cavitation, avoid the possible cavitation caused by throttling damage to the valve body and pipeline.

· Linear adjustment: The valve opening and flow are linear, enabling accurate adjustment.

· Low maintenance cost: the valve is specially designed to reduce the possibility of being stuck by sundries. The valve is equipped with hand hole cover and backwash device. Convenient for regular maintenance and overhaul.

· Long life: Reasonable flow path and appropriate bride price selection ensure the long service life of the valve.

· Small driving force: hydraulic balance design, coupled with guide strip surfacing copper alloy to ensure more stable and reliable piston operation.

· Optional installation: The valve can be installed vertically, horizontally, suspended, or on either side of the pipe.

· Reliable sealing (general type) : High performance elastic silica gel connected metal seats provide bubble class sealing effect, and effectively prevent seat scratch, extend seat life. (figure A)

· Impact energy dissipation and vibration resistance (multi-injection hole type) : the spiral holes are evenly and symmetrically arranged in the direction of the circumference of the sleeve to make the water column impact energy dissipation and the energy completely disappear after impact, effectively preventing the violent vibration caused by energy dissipation under high pressure difference. (B)

· Cone-Hole design, anti-cavitation (multiple injection holes) : special cone-hole design can accelerate the water flow through the sleeve and make cavitation occur in the center of the valve, effectively preventing cavitation damage to valve parts under high pressure difference. (C)

Material table for each component

serial number

1

2

3

4

5

6

7

8

9

10

11

12

name

阀体

V型填料

阀轴

轴承

手盖孔

曲柄

活塞

阀座

连杆

驱动杆

驱动销

反冲洗套管（可选）

material

球墨铸铁/铸钢

丁晴橡胶

不锈钢

铜合金

球墨铸铁/铸钢

不锈钢

不锈钢

不锈钢

不锈钢

不锈钢

不锈钢

不锈钢

The ordinary type piston type control valve is used for the working condition with small pressure difference and medium containing suspended matter. Ordinary water flows into the shell from the axial arc and contracts towards the axis at the exit. Cavitation bubbles caused by the collision are restricted in the center of the pipe and completely surrounded by water. Even though these bubbles are unstable and burst, they are in the center of the pipe and are not pipe and valve pipework. Therefore, no cavitation rupture is produced.

Multi - injection piston type control valve due to high pressure difference, high control accuracy requirements. The orifice on the multi-orifice valve seat is designed according to the specific working condition. The orifice is symmetrically distributed on the wall of the valve seat, and the water flow hits the center line of the valve through the orifice. The rapid reduction in radial velocity and the small turbulence zone in the center of the seat result in violent collisions and friction within the water, eliminating most of the energy force.

One, four kinds of control

2. used for pump outlet control valve. Open slow: Close 90% quickly, then close slowly. Head loss is minimal.

3.Used for air flow control in aerator of active sludge discharge tank in sewage treatment plant

4.Used for inlet opening and closing and by-pass control of water turbine

Example: PPEH-1000-16QR represents nominal size DN1000, nominal pressure 1.6mpa, main material is nodular cast iron, general type electric piston type control valve and the operator is installed on the right side of the water flow direction