SU1381448A1 - Controlled check valve for pipelines - Google Patents

Abstract

The invention relates to devices for automatically shutting off a large diameter pipe when the flow direction changes. The aim of the invention is to create an adjustable non-return valve having a constant predetermined hydraulic resistance due to the installation on the rotary axis 4 of the shutter 3 of the lever 6 with a movable movable counterweight 7, controlled automatically by the commands of the sensor 10 of the differential pressure on the valve. I il.

Description

(L

with

00

The invention relates to devices for automatically shutting off large diameter pipelines (1200 mm and more) when the direction of flow of gas or liquid in the pipeline is reversed, i.e. to check valves;

The purpose of the invention is to maintain a constant hydraulic resistance of the check valve at any flow rate through it.

The drawing shows a control valve “check valve”, a pitch section (along the axis of the pipeline) (arrow A shows the direction of the flow of gas or liquid

The adjustable check valve includes a housing 1 with a saddle 2 and a rotary shutter 3 fixed on the rotation axis 4 by means of a lever 5. On the same axis 4 a lever 6 is installed with a movable counterweight 7, which is moved by the actuator 8 of the counterweight 7 via chain transfer 9. A differential pressure sensor 10 is connected to the valve gate 3, connected via a control unit (not shown) to the actuator 8.

Adjustable check valve works as follows.

When a stream of gas or liquid flows through the valve in arrow A, a shutter 3 opens, which in this case rotates in an axis 4 of rotation counterclockwise at an angle. When a medium flows through a valve, pressure is lost on it. If this loss exceeds the setting pressure of the sensor 10, the latter gives a command through the control unit to turn on the actuator 8 for displacing the counterweight 7, and the counterweight 7 moves to the left. This increases the torque of the counterweight 7 relative to the axis 4 of rotation of the shutter 3, compensating for the necessary torque generated by the shutter 3 relative to the axis 4

Compiled by Editor L.Pcholinska Tehred L.Se

ten

20

25

814482

scheni The hydraulic resistance of the non-return valve is reduced to the value specified by sensor 10.

With an increase in the flow rate of the medium through the check valve, the shutter 3 rotates through a larger angle to skip this flow, while increasing the torque from the weight of the shutter 3 relative to the axis of rotation 4, as the shoulder of the center of gravity of the shutter 3 increases relative to this axis. Consequently, the hydraulic resistance of the valve increases, the pressure differential sensor 10 again commands the drive of the counterweight moving actuator 8 7, which moves further to the left, to compensate for the increased shutter torque 3. The hydraulic resistance of the valve decreases again to the value specified by the differential pressure sensor 10.

As the flow through the check valve decreases, the counterweight 7 moves to the right, maintaining the valve’s fixed hydraulic resistance at all times. To ensure the minimum resistance of the check valve, it is necessary to set the differential pressure sensor 10 to the minimum differential pressure determined by its sensitivity limit.

thirty

I

Claims (1)

Invention Formula An adjustable non-return valve for pipelines, comprising a body with a saddle and a shutter mounted on the axis of rotation, characterized in that, in order to maintain a constant hydraulic resistance of the non-return valve at any flow through it, the lever is mounted on the axis of rotation. a counterweight, a differential pressure sensor at the gate, a control unit connected to it, a counterweight drive, connected to a control unit. Proofreader A.Zimokosov