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As an improved product of needle valve, piston control valve has been active in long-term water delivery, dam and hydropower station. Piston control valve is a reasonable design, simple operation, low maintenance rate and economic and effective energy dissipation valve. It is also a flow and pressure regulating valve suitable for special working conditions.

Piston control valve is mainly composed of valve body, valve seat, piston, valve shaft, crank, connecting rod, driving pin, taper pin, bearing and operating mechanism. The piston control valve transforms the rotation of the valve shaft into the axial movement of the piston along the guide rail through the crank connecting rod mechanism. In the process of the piston moving forward and backward, the flow regulation and pressure control are realized by changing the flow area between the piston and the valve seat.
The water flows into the valve body from the axial arc, and the flow passage in the piston control valve is axisymmetric, and the fluid will not produce turbulence when it flows through. No matter where the piston moves to any position, the water flow section in the valve chamber is annular at any position, and it shrinks to the axis at the outlet, so as to prevent cavitation from damaging the valve body and pipeline caused by throttling.

Piston control valve is mainly composed of valve body, valve seat, piston, valve shaft, crank, connecting rod, driving pin, taper pin, bearing and operating mechanism. The piston control valve transforms the rotation of the valve shaft into the axial movement of the piston along the guide rail through the crank connecting rod mechanism. In the process of the piston moving forward and backward, the flow regulation and pressure control are realized by changing the flow area between the piston and the valve seat.
The water flows into the valve body from the axial arc, and the flow passage in the piston control valve is axisymmetric, and the fluid will not produce turbulence when it flows through. No matter where the piston moves to any position, the water flow section in the valve chamber is annular at any position, and it shrinks to the axis at the outlet, so as to prevent cavitation from damaging the valve body and pipeline caused by throttling.

Material list of each component

Serial number

1

2

3

4

5

6

7

8

9

10

11

12

name

valve body

VV-packing

Valve shaft

Bearing

Handcap hole

crank

piston

valve seat

connecting rod

Driving lever

Drive pin

Backwash sleeve (optional)

Ductile iron / cast steel

Butadiene rubber

SUS304

copper alloy

QT450/WCB

SUS304

SUS304

SUS304

SUS304

SUS304

SUS304

SUS304

The common piston control valve is used in the condition of small pressure difference and medium containing suspended solids. The ordinary water flows into the shell from the axial arc, and contracts to the axis at the outlet. The cavitation bubbles caused by collision are limited in the center of the pipe and are completely surrounded by water. Even if these bubbles break due to instability, they are in the center of the pipe and not on the wall of the pipe and valve. Therefore, there is no cavitation fracture.

Because of the high pressure difference and high control precision, the multi orifice piston control valve is used. The spray holes on the multi orifice valve seat are designed according to the specific working conditions. The small holes are symmetrically distributed on the wall of the valve seat, and the water flow collides with the center line of the valve through the small holes. In the turbulent area with small stroke in the center of the valve seat, the violent collision and friction inside the water eliminated most of the capacity.

1、 Four control modes

2、 Control valve for pump outlet. Open type slow opening: fast closing 90% and then closing slowly. The head loss is very small.

3、 Air flow control in aeration pipeline of activated sludge tank in sewage treatment plant

4： It is used for inlet opening and closing and bypass control of hydraulic turbine

Example: ppeh-1000-16qr means that the nominal size is DN 1000, the nominal pressure is 1.6Mpa, the main material is ductile iron, and the ordinary electric piston control valve is installed on the right side of the water flow direction