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Ningbo RMI Plastic Co.,Ltd


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  • PP Butterfly Valve Wafer Type DIN PN10
    PP Butterfly Valve Wafer Type DIN PN10
  • PPH Diaphragm Valve JIS 10K
    PPH Diaphragm Valve JIS 10K
  • PPH Ball Valve Flange End Lever Handle
    PPH Ball Valve Flange End Lever Handle
  • PVC True Union Ball Valve Socket End
    PVC True Union Ball Valve Socket End
  • PVDF Ball Check Valve ANSI
    PVDF Ball Check Valve ANSI
  • PVC Bottom Valve Flange End ANSI CL150
    PVC Bottom Valve Flange End ANSI CL150
  • PVDF Swing Check Valve Flanged PN10
    PVDF Swing Check Valve Flanged PN10
  • Plastic Diaphragm Valve Pneumatic Actuatored
    Plastic Diaphragm Valve Pneumatic Actuatored
  • PVC Vanstone flange PN16
    PVC Vanstone flange PN16
  • Plastic Shell Motorized Actuator Rotary Switch Type
    Plastic Shell Motorized Actuator Rotary Switch Type


we are a professional manufacturer and exporter of plastic valves and piping materials, provide consult service and supply high quality piping materials for industrial application, water treatment system, irrigation systems, etc. RMI products cover full range of plastic valves, pipes, fittings and accessories by different materials of PVDF, PVC, PVC-C, PP, PP-H, PP-GF, FRP, EPDM, VITON, PTFE. Over 30 kinds different valves include Diaphragm Valve, BALL VALVE, Check Valve, BUTTERFLY VALVE, Foot Valve, Globe Valve, etc. Size from 1/2" up to 32", following standard of DIN, JIS, ANSI, CNS, ISO. 8 different materials of pipes and fittings diameter from 16mm to 600mm. With high quality products and professional technical support, we serve more than 200 customers in different industries and areas all around the world, and win good reputation. Especially in steel industrial, chloride alkali industry, metallurgical industry, paper making industry, pharmaceutical factory, electroplating factory, mining plant, fish farm, etc. We are continual working for the target of quality improving, technical innovation and service satisfied. Aim to provide customer durable and efficient products to ensure the piping system working safer and longer.
  • 24
    24 H Online Service No Time Difference.
  • 2006
    We Were Established In 2006.
  • 5
    Our Factory Have More Than 5 Employees.
  • 5000
    More Than 5000 Square Meters Technical R&D Building.
  • Check valve selection criteria are as follows: 1. In order to prevent reverse flow of medium, check valves should be installed on equipment, devices and pipelines; 2. Check valve is generally suitable for clean media, not for media with solid particles and high viscosity; 3. Generally, the horizontal lifting check valve should be used in the horizontal pipeline with nominal diameter of 50 mm; 4. Straight through lifting check valve can only be installed in horizontal pipeline; 5. For the pump inlet pipeline, the bottom valve should be selected. Generally, the bottom valve is only installed on the vertical pipeline at the pump inlet, and the medium flows from bottom to top; 6. Lifting type is better than swing type in sealing and fluid resistance. Horizontal type should be installed on horizontal pipeline and vertical type on vertical pipeline; 7. The installation position of swing check valve is not limited. It can be installed on horizontal, vertical or inclined pipelines. If it is installed on vertical pipelines, the flow direction of medium should be from bottom to top; 8. Swing check valve should not be made into small diameter valve, but can be made into high working pressure, the nominal pressure can reach 42MPa, and the nominal diameter can also be very large, the maximum can reach more than 2000mm. According to the different materials of shell and seal, it can be applied to any working medium and any working temperature range. The m
    2021-03 02
  • Check Valve Installation method 1. Swing check valve: the disc shape of the swing check valve rotates around the axis of the seat channel. Because the channel inside the valve is streamlined, the flow resistance is smaller than that of the lift check valve. It is suitable for large-diameter occasions with low flow rate and variable flow, but it is not suitable for pulsating flow, and its sealing performance is inferior to that of the lift check valve. Swing check valve is divided into three types: single valve type, double valve type and half valve type. These three types are mainly divided according to the valve diameter, in order to prevent the hydraulic impact from weakening when the medium stops flowing or reverses. 2. Lift check valve: the check valve whose valve disc slides along the vertical center line of the valve body. The lift check valve can only be installed on the horizontal pipeline. On the high-pressure small-diameter check valve, the disc can be a ball. The body shape of the lift check valve is the same as that of the stop valve, so its fluid resistance coefficient is larger. Its structure is similar to the stop valve, and the valve body and disc are the same as the stop valve. The upper part of the valve disc and the lower part of the valve cover are provided with guide sleeve. The guide sleeve of the valve disc can rise and fall freely in the guide sleeve of the valve cup. When the medium flows downstream, the valve disc will open by the medium thrust. When the medium stops flowing, the valve disc will fall on the valve seat by itself to prevent the medium from flowing backward. The direction of medium inlet and outlet channel of straight through lift check valve is perpendicular to the direction of valve seat channel; the direction of medium inlet and outlet channel of vertical lift check valve is the same as that of valve seat channel, and its flow resistance is smaller than that of straight through check valve.
    2021-02 16
  • Check valve is a kind of valve whose opening and closing parts are round disc, and its action is produced by its own weight and medium pressure to block medium backflow. Belong to automatic valve class, also known as check valve, one-way valve, return valve or isolation valve. Disc movement is divided into lifting type and swing type. Lift check valve is similar to globe valve in structure, only lack of stem to drive disc. The medium flows in from the inlet end (lower side) and flows out from the outlet end (upper side). When the inlet pressure is greater than the disc weight and its flow resistance, the valve is opened. On the contrary, the valve will be closed when the medium flows back. The swing check valve has an inclined disc which can rotate around the shaft. Its working principle is similar to that of the lift check valve. Check valve is often used as the bottom valve of pumping device, which can prevent the backflow of water. Combined use of check valve and stop valve can play the role of safety isolation. The disadvantages are high resistance and poor sealing when closing. working principle The check valve can also be used to supply the auxiliary system whose pressure may rise above the system pressure. Check valve can be divided into swing check valve (rotating according to the center of gravity) and lift check valve (moving along the axis). Check valve the function of this type of valve is to only allow the medium to flow in one direction and prevent the flow in the opposite direction. Usually, this kind of valve works automatically. Under the action of fluid pressure flowing in one direction, the valve disc opens; when the fluid flows in the opposite direction, the fluid pressure and the dead weight of the valve disc act on the valve seat, thus cutting off the flow. Check valve belongs to this type of valve, which includes swing check valve and lift check valve. The swing check
    2021-02 15
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