Butterfly valve selection, installation and construction points

A butterfly valve is a valve that uses a disc-type opening and closing member to rotate back and forth 90 degrees. Left and right to open, close or adjust the media flow.

The butterfly valve is not only simple in structure, small in size, light in weight, low in material consumption, small in installation size, small in driving torque, easy and fast in operation, but also has good flow regulation and sealing characteristics. at the same time. It has been developed over the past ten years. One of the fastest valve varieties. Butterfly valves are very versatile. Its use types and numbers continue to expand and develop towards high temperature, high pressure, large diameter, high sealing performance, long life, excellent regulating characteristics and a valve with multiple functions.

Construction and installation points of butterfly valve:

1) The installation position, height and direction of import and export must meet the design requirements, and the connection should be firm and firm.

2) Various manual valves installed on the insulated pipeline shall not be operated downwards.

3) The valve must be visually inspected before installation. The nameplate of the valve should comply with the current national standard "General Valve Mark" GB12220. For the valve with a working pressure greater than 1.0 MPa and a shut-off function on the main pipe, the strength and sealing performance test should be carried out. Please take it out before installation, and the valve can only be used after it is qualified. In the strength test, the test pressure is 1.5 times the nominal pressure, and the duration is not less than 5min. The valve shell and packing should be qualified without leakage. During the air tightness test, the test pressure shall be 1.1 times the nominal pressure; during the test, the test pressure shall meet the requirements of the GB 50243 standard, and there shall be no leakage on the sealing surface of the valve disc.

The main points of butterfly valve product selection:

1. The main control parameter of the butterfly valve is the specification.

2. The butterfly valve is a single-plate air valve with simple structure, convenient processing, low cost and simple operation, but poor adjustment accuracy. Only suitable for switching or coarse adjustment in ventilation and air conditioning systems.

3. Can be operated manually, electrically or by zipper, and can be fixed at any angle within 90 degrees.

4. Due to the single shaft and single valve plate, in the case of large pressure difference and large flow, the bearing capacity of the bearing is limited, and the service life of the valve is short. The valve is divided into closed type and ordinary type, thermal insulation type and non-thermal insulation type.

5. The electric butterfly valve has only two-position control, and the electric actuator is the same as that of the multi-leaf valve.