cross sectional drawing of a safety valveKEEP YOUR SYSTEM IN CHECK

Safety Valve is one of the most crucial accessories in a chemical dosing system. It is also referred as pressure relief valve in the industry. Safety valve helps to prevent system being over pressure. In a typical setup, it shall be installed along the return pipeline after the metering pump. While installing a safety valve, it shall be installed as close as possible towards the dosing pump and there shouldn’t be any valve in between. When the pressure in the system pipeline exceeds the preset value, the diaphragm and the shaft are jacked up, and the medium is discharged back to the return pipe. The preset value can be adjusted directly on the safety valve itself. The preset value can be adjusted within 0 – 1Mpa by adjusting the adjustable nut. The relief pressure is generally set higher than the system pressure by 0.1-0.2Mpa and not exceeding the maximum pressure of the metering pump.

Back pressure valve is very similar to safety valve, but the emphasis is on steady state pressure control instead of on/off actuation. It shall be installed on the positive pressure side along the discharge pipe of the metering pump. A back-pressure valve can prevent the occurrence of siphoning and reduce unstable dosage which is caused by the pressure fluctuation. To adjust the set value, remove the protective cap, rotate the adjusting nut, and set within the range of 0-0.6 MPa. It is commonly used in conjunction with the pulsation damper to reduce the vibration damage towards the system. On the discharge, the flow will be more stable with the installation of back pressure valve.


Material UPVC, PP, CPVC, PVDF, SUS304, SUS316;
Working Pressure 0~1.0MPa or


Inlet/Outlet Size DN15, DN20, DN25, DN32, DN40, DN50, DN65
Connection Method Glue Union, Weld Union, Threaded, Flange, Hose Compression Fitting
Diaphragm PTFE + Rubber


  • Ensure the system pressure is stable and consistent, prevents over pressurized your system.

  • Protect your pumps and ensure system stability.

  • Reduce flow fluctuation and protect your system from vibrations caused by the flow fluctuation.

  • Diaphragm is made of a combination of PTFE and Rubber. Designed to handle corrosive liquid and ensure top performance sealing without leakage.

disassembled view of a safety and back pressure valve

various sizes of safety valve by WRS Chemical Dosing Manufacturer 186 1SS Type back pressure valveFlange Connection of safety valve back pressure valve


safety valve series 186 standard union connection dimensional drawing
Model Size L H D d z h
18615 DN15 175 181 82 20 22 27
18620 DN20 174 181 82 25 19 29
18625 DN25 202 198 107 32 21 33
18632 DN32 251 198 107 40 31 35
18640 DN40 285 260 155 50 31 60
18650 DN50 355 260 155 63 39 60
18665 DN65 367 260 155 75 41 65


safety valve series 186 f flange connection dimensional drawing
Model Size L H D d h
18615-F DN15 128 181 82 95 27
18620-F DN20 130 181 82 105 29
18625-F DN25 158 198 107 115 33
18632-F DN32 180 198 107 140 35
18640-F DN40 220 260 155 150 60
18650-F DN50 225 260 155 165 60
18665-F DN65 238 260 155 185 65


safety valve series 186 h hose connection dimensional drawing

Available Sizes:

  • ɸ6
  • ɸ 8
  • ɸ 12

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