Author:Site Editor Publish Time: 2019-01-25 Origin:Site
l What Is Instruction?
l What Should You Pay Attention to?
1. Swing-type check valve: The valve flap of the swing-type check valve is in the shape of a disk, and rotates around the rotating shaft of the valve seat passage. Since the valve passage is streamlined, the flow resistance is smaller than that of the lift check valve. It is suitable for large diameter applications where low flow rate and flow are not changing frequently, but it is not suitable for pulsating flow, and its sealing performance is not as good as lifting type. The swing-type check valve is divided into three types: single-valve, double-valve and multi-half. These three forms are mainly divided according to the valve diameter. The purpose is to prevent the hydraulic shock from being weakened when the medium stops flowing or reverses.
2. The lift check valve: the check valve sliding along the vertical center line of the valve body, the lift check valve can only be installed on the horizontal pipe, the valve can be used on the high pressure small diameter check valve . The shape of the lift check valve is the same as that of the shut-off valve (common to the shut-off valve), so its fluid resistance coefficient is large. Its structure is similar to the stop valve, the valve body and the valve flap are the same as the shut-off valve. The upper part of the valve flap and the lower part of the valve cover are machined with a guide sleeve, and the valve guide can be easily lifted and lowered in the valve guide. When the medium is downstream, the valve flap is opened by the medium thrust. When the medium stops flowing, the valve flap is self-retained. The drooping falls on the valve seat to prevent the medium from flowing back. The direction of the inlet and outlet passages of the straight-type lifting check valve is perpendicular to the direction of the valve seat passage; the vertical lift check valve has the same direction of the medium inlet and outlet passages as the valve seat passage, and its flow resistance is smaller than that of the straight-through type.
3. The disc type check valve: a check valve that rotates around the pin shaft in the valve seat. The disc type check valve has a simple structure and can only be installed on a horizontal pipe, and the sealing property is poor.
4. Pipeline check valve: A valve whose valve slides along the center line of the valve body. Pipeline check valve is a new type of valve. It is small in size, light in weight and good in processability. It is one of the development directions of check valves. However, the fluid resistance coefficient is slightly larger than the swing check valve.
5. Press-type check valve: This valve is used as a boiler feed water and steam shut-off valve. It has a comprehensive function of a lift check valve and a shut-off valve or an angle valve.
In addition, there are some check valves that are not suitable for pump outlet installation, such as bottom valves, spring type, Y type, etc.
1. Do not allow the check valve to bear weight in the piping system. The large check valve should be independently supported so that it is not affected by the pressure generated by the piping system.
2. When installing, pay attention to the direction of the medium flow should be consistent with the direction of the arrow marked on the valve body.
3. The lifting vertical flap check valve should be installed on the vertical pipe.
4. The lift horizontal flap check valve should be installed on the horizontal pipe.
When placing pipes, attention should be paid to keeping the flow direction of the check valve in line with the flow direction of the fluid.Installed in the vertical pipeline. For horizontal pipelines, vertically place the check valve with a pair of clamps.Use a telescopic pipe between the clip check valve and butterfly valve. Never connect it directly with other valves When installing the clip check valve around the elbow, be careful to leave enough space. When installing the clip check valve at the pump outlet, at least six times the valve diameter will flow out to ensure that the butterfly plate is ultimately affected by the fluid.
In order to ensure that the disc can reach the proper position on the seat surface every time, the disc is set in a hinge mechanism so that the disc has enough swing space and makes the disc truly and comprehensively contact with the seat.
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