Butterfly Valve Classification

- Apr 13, 2020-

Butterfly valve classification

Main classification

Divided by driving method

(1) Electric butterfly valve

(2) Pneumatic butterfly valve

(3) Hydraulic butterfly valve

(4) Manual butterfly valve

Divided by structure:

(1) Central seal butterfly valve

(2) Single Eccentric Seal Butterfly Valve

(3) Double eccentric seal butterfly valve

(4) Triple Eccentric Seal Butterfly Valve

Material of sealing surface:

(1) Soft seal butterfly valve.

1) The sealing pair is composed of a non-metal soft material to a non-metal soft material.

2) The sealing pair is composed of a metal hard material and a non-metal soft material.

(2) Metal hard seal butterfly valve. The sealing pair is composed of a metal hard material to a metal hard material.

Divided by seal form:

(1) Forced-seal butterfly valve.

1) Elastic seal butterfly valve: The specific pressure of the seal is generated by the valve plate pressing the valve seat when the valve is closed, and the elasticity of the valve seat or valve plate.

2) Torque-sealed butterfly valve: The specific pressure of the seal is generated by the torque applied to the valve shaft.

(2) Filling and sealing butterfly valve: The sealing specific pressure is generated by the filling pressure of the elastic sealing element of the valve seat or the valve plate.

(3) Automatic sealing butterfly valve: The sealing specific pressure is automatically generated by the medium pressure.

According to working pressure:

(1) Vacuum butterfly valve. Butterfly valve whose working pressure is lower than the standard atmospheric pressure.

(2) Low pressure butterfly valve. Butterfly valve with nominal pressure PN <1.6MPa.

(3) Medium pressure butterfly valve. Butterfly valve with nominal pressure PN of 2.5-6.4MPa.

(4) High pressure butterfly valve. Butterfly valves with a nominal pressure PN of 10.0--800.0 MPa.

(5) Ultra high pressure butterfly valve. Butterfly valve with nominal pressure PN> 100MPa.

According to operating temperature:

(1) High temperature. t> 450 ° C butterfly valve.

(2) Medium temperature butterfly valve. 120 C <t <450 ℃ butterfly valve.

(3) Normal temperature butterfly valve. A butterfly valve of 40C <t <120 ° C.

(4) Low temperature butterfly valve. -100 <t <-40 ° C butterfly valve.

(5) Ultra-low temperature butterfly valve. t <a 100 ° C butterfly valve.

Divided by connection method:

1. Wafer type butterfly valve

The butterfly plate of the wafer butterfly valve is installed in the diameter direction of the pipeline. The valve is fully open.

Wafer type butterfly valve has simple structure, small size and light weight. Butterfly valve has two types of sealing: elastic seal and metal seal. Elastically sealed valve, the sealing ring can be embedded in the valve body or attached to the periphery of the butterfly plate.

2.Flanged butterfly valve

The flange type butterfly valve is a vertical plate structure, and the valve stem is a sealing ring of the integral metal hard sealing valve.

It is a composite structure of flexible graphite plate and stainless steel plate, which is installed on the valve body. The sealing ring of the soft-sealed valve is made of nitrile rubber and is installed on the butterfly plate.

3.Lug butterfly valve

4.Welded butterfly valve

Welded butterfly valve is a kind of non-closed butterfly valve, widely used in the production process of building materials, metallurgy, mining, electricity and other media on the medium temperature ≤ 300 ℃ nominal pressure of 0.1Mpa pipeline, used to communicate, open and close or adjust the amount of medium.

Electric regulating butterfly valve belongs to a variety of electric valves and electric regulating valves. The connection methods are mainly flange type and wafer type, which are important execution units in the field of industrial automation control. Two major analysis points for the installation of electric regulating butterfly valves: the installation position, height, and inlet and outlet directions must meet the design requirements. Note that the direction of medium flow should be consistent with the direction of the arrow marked on the valve body, and the connections should be firm and tight. The appearance of the electric regulating butterfly valve must be checked before installation. The nameplate of the valve should comply with the current national standard "General Valve Mark" GB12220. For valves with a working pressure greater than 1.0 MPa and a cut-off function on the main pipe, strength and tight performance tests should be performed before installation. Only qualified after use. In the strength test, the test pressure is 1.5 times the nominal pressure, and the duration is not less than 5min. The valve housing and packing should be qualified without leakage. The electric regulating butterfly valve can be divided into offset plate type, vertical plate type, inclined plate type and lever type according to the structure form; according to the sealing form, it can be divided into two types: soft seal type and hard seal type; soft seal type generally uses rubber ring seal and hard seal type Metal ring seals are usually used. Several kinds of electric. Good development prospects