Insulation valve is a plug-shaped opening and closing valve-shaped valve, sealing surface was flat or conical surface, the valve flap along the centerline of the fluid for linear motion. The movement of the valve stem in the form of lift rod (stem up and down, hand wheel does not lift), but also lift the rotating lever (hand wheel and stem rotation with the lift, the nut is located on the valve body). Line pipe cut-off valve is only applicable to fully open and fully closed, not allowed for regulation and throttling.

Thermal cut-off valve is a mandatory sealed valve, so the valve is closed, the valve must be applied pressure to force the sealing surface does not leak. When the media from the valve below the valve into the valve 6, the operating force to overcome the resistance is the stem and packing friction and the pressure generated by the medium of the thrust, the force off the valve than to open the valve force, so the valve The diameter of the rod to be large, or it will occur stem top bend of the fault. In recent years, since the emergence of self-sealing valve, the flow direction of the valve to change from the top of the valve into the valve chamber, then the pressure in the medium under the force off the valve is small, and open the valve force, stem The diameter can be reduced accordingly. At the same time, the role of the media, this form of the valve is more stringent. China's valve "three to" has provided that the flow of cut-off valve, all top-down.

Insulation valve is opened, the valve flap opening height, nominal diameter of 25% to 30%, the flow has reached the maximum, said the valve has reached the fully open position. So cut-off valve fully open position, the valve should be determined by the stroke.

The type of gas valve cut-off valve according to the location of the thread there are external threads, internal thread type. According to the flow of media points, there are straight-through, DC and angle. Cut-off valve in the form of sub-points, there are packing sealed globe valve and bellows sealed shut-off valve.

1, simple structure, manufacturing and maintenance more convenient.

2, the working stroke is small, opening and closing time is short.

3, good sealing, sealing surface friction between the small, long life.

Insulation valve shortcomings are as follows:

1, the fluid resistance, open and close the required force greater.

2, does not apply to particles with a large viscosity, easy to coke of the media.

3, poor regulation performance.

LPG shut-off valve

The type of thread according to the location of the valve stem thread type, internal thread type. According to the flow of media points, there are straight-through, DC and angle. Cut-off valve in the form of sub-points, there are packing sealed globe valve and bellows sealed shut-off valve.

1, hand wheel, handle the operation of the cut-off valve can be installed in any position on the pipeline.

2, hand wheel, handle and Wei moving agencies, is not allowed to use lifting.

3, the direction of flow of media should be consistent with the direction of the arrow shown in the valve body.

Insulation valve, also known as the cut-off door, is the most widely used of a valve, it is popular, is due to the process of opening and closing the friction between the sealing surface is small, more durable, open height is not easy to manufacture, Easy maintenance, not only for low pressure, but also for high pressure. Its closed principle is to rely on the valve stem pressure, so that valve sealing surface and valve seat sealing surface closely fit to prevent the flow of media.

Insulation valve only one-way medium flow, the installation direction. Its structure is longer than the gate valve, while the fluid resistance, long-term operation, the sealing reliability is not strong.

Insulation valve is divided into three categories: straight-through, right angle and DC oblique stop valve.

Insulation valve is opened, the valve flap opening height, nominal diameter of 25% to 30%, the flow has reached the maximum, said the valve has reached the fully open position. So cut-off valve fully open position, the valve should be determined by the stroke.