Design and selection of adjustable pressure reducing valve

(1) the adjustable pressure reducing valve used in the engineering type is a product that has passed the inspection, has complete marks, and the technical data meet the requirements.

(2) select the type of valve according to the functional requirements, and then determine the material of the valve body and sealing part of the valve according to the pipeline transmission medium, temperature, building standards and owner's requirements. Commonly used valve body materials include cast iron, copper iron, copper, plastic, etc. Common sealing surface and lining materials include copper alloy, plastic, steel, cemented carbide, rubber, etc. The material of valve body shall match the material of pipeline.

(3) the nominal pressure of the valve has different levels, such as 0.6, 1.0, 1.6, 2.5 and 4.0Mpa. The working pressure of the medium transported by the pipeline should be less than the nominal pressure of the valve.

(4) the setting of hydraulic control valves in the project should have enough space for management, operation, installation and maintenance, and should meet the requirements of pipelines for valves.

(5) when the pipeline is connected by flange, the hydraulic control valve connected by flange shall be used; When the pipeline adopts grooved connection, the hydraulic control valve with grooved connection shall be used.

(6) the piston type adjustable pressure reducing valve should be set on the pipeline with one-way flow of medium.

(7) the arrow direction on the main valve body of the piston type adjustable pressure reducing valve must be consistent with the flow direction of the pipeline system.

(8) the pipe section connected to the hydraulic control valve shall be free of air blockage and air resistance. Automatic exhaust valve shall be set in the gas storage section of the pipe network ≤ position.

(9) when the valve is installed horizontally, the valve cover and valve rod should face upward. When installed vertically, the valve cover and valve rod should face outward.

(10) strength and tightness tests shall be conducted before valve installation.

(11) the strength and tightness test of the valve shall meet the following requirements.

A. The strength test pressure of the valve is 1.5 times of the nominal pressure;

B. The tightness test pressure of the valve is 1.5 times of the nominal pressure;

C. The test pressure shall remain unchanged during the test duration, and there shall be no leakage on the shell packing and the sealing surface of the valve disc;

D. The duration of valve test is as shown in the above table.