Butterfly valve refers to the closure (disc or butterfly plate) for the disc, around the valve shaft rotation to achieve the opening and closing of a valve, the main cut off and throttling in the pipeline. Butterfly valve opening and closing parts is a disc-shaped butterfly plate, in the valve body around its own axis of rotation, so as to achieve the purpose of opening or closing or adjustment. Butterfly valve fully open to the whole is usually less than 90 °, butterfly valve and butterfly rod itself does not have self-locking ability, in order to butterfly plate positioning, to install the worm on the stem reducer. The use of worm reducer, not only can make the disc with self-locking ability, so that the butterfly plate to stop at any position, but also improve the valve operating performance. Industrial special butterfly valve features high temperature, suitable pressure range is also high, the valve nominal diameter, the valve body made of carbon steel, valve plate ring with metal ring instead of rubber ring. Large-scale high-temperature butterfly valve made of steel plate welding, mainly used for high-temperature medium of the smoke duct and gas pipeline.
Stem diameter: for multi-turn class stem valve. It can not be assembled into electric valves. Therefore, if the electric butterfly valve device allows the maximum stem diameter to pass through the valve stem of the valve. The inner diameter of the hollow shaft of the electric device must be greater than the stem diameter of the stem valve. For the local rotary valve and multi-turn valve in the dark bar valve, although not consider the stem diameter through the problem, but should also take into account the selection of stem diameter and keyway size, so that after assembly to work properly.
Operating Torque: The operating torque is the most important parameter for selecting the valve motor. The electric butterfly valve movement process can be controlled by the stroke, the torque or the axial thrust. As the operating characteristics of the valve and the utilization of the valve depends on the type of valve, the device work norms and the valve in the pipeline or equipment on the location of the valve electric butterfly valve device is to achieve the valve program control, automatic control and remote control indispensable equipment. Therefore, the correct choice of valve electric device, to prevent the occurrence of overload (working torque is higher than the control torque) is essential. Usually, the correct choice of valve electric butterfly valve device basis.
The output torque of the electric device shall be 1.2-1.5 times the maximum torque of the valve operation.
Electric butterfly valve operation thrust: valve electric device host structure there are two: one is not configured thrust plate. The output torque is converted to output thrust by the stem nut in the thrust plate. Direct output torque; the other is to configure the thrust plate.
Number of revolutions of the output shaft: The number of turns of the output shaft of the valve motor is related to the nominal diameter of the valve, the stem pitch and the number of threads. H is the opening height of the valve, according to M = HZS calculation (M for the electric device should meet the total number of turns. S for the stem drive thread pitch, Z for the stem thread head number.
Butterfly valve, also known as flap valve, commonly used in the furnace, gas, natural gas, liquefied petroleum gas, hot and cold air, chemical smelting and other engineering systems to transport a variety of corrosive, non-corrosive fluid medium for regulating and truncation Media flow.
Butterfly valve installation matters
1, butterfly valve installed before the need to confirm product performance and media flow arrows are consistent with the movement conditions, and the valve chamber scrub clean, not allowed in the seals and butterfly plate with impurity foreign body, not allowed to be closed before cleaning Butterfly plate, so as not to damage the seal.
2, discs supporting the installation of flanges recommended disc valve dedicated flange, that is, HGJ54-91 type welded steel flange.
3, installed in the pipeline position, the best location for the standing equipment, but can not flip.
4, the need to adjust the use of flow, a worm gear box to control.
5, open, closed more times the disc valve, in about two months time, open the worm gear cover, check the butter is normal, should keep the amount of butter.
6, check the connection parts of the requirements of compression, that is to ensure that the sealing of the filler, but also to ensure flexibility and flexible stem.
7, metal seal butterfly valve products are not suitable for installation at the end of the pipeline, such as must be installed at the end of the pipeline, need to take the export flange, to prevent the seal squeeze, over position.
8, regularly check the valve use effect, found that the failure to rule out.