Safety valve: In the system, the pipeline pressure is too high, can play a timely release pressure, the protection of the pump, and the liquid recovery. Also used as a relief valve. Back-pressure valve: the pressure in the pipeline or equipment containers under pressure, to maintain the pressure required by the pipeline, so that the pump can output the normal flow. The other end of the pump due to gravity or other functions often appear siphon phenomenon, then the back pressure valve can reduce the siphon flow and pressure fluctuations. Commonly used materials: PVC SUS304 SUS316 Teflon commonly used Diameter: DN10 DN15 DN25 DN32 DN40 pulse dampener: 95% can reduce the pulse generated by the metering pump running, usually installed in the outlet pipe and close to the metering pump. Commonly used materials: PVC SUS304 SUS316 lined with PTFE Common Diameter: DN10 DN15 DN25 DN32 DN40 diaphragm pulse damper: to reduce 95% generated by the metering pump pulse, usually installed in the outlet pipe and close to the metering pump, the application In high-risk places, with a PTFE membrane. Commonly used materials: PVC SUS304 SUS316 lined with PTFE Common Diameter: DN10 DN15 DN25 DN32 DN40 Y-type filter: to filter impurities in the media, the metering pump to form a protective effect, generally installed in the inlet pipe and close to the metering pump. Commonly used materials: PVC SUS304 SUS316 lined with PTFE Common Diameter: DN10 DN15 DN25 DN32 DN40 Y-type filter: to filter impurities in the media, the metering pump to form a protective effect, generally installed in the inlet pipe and close to the metering pump. Commonly used materials: PVC SUS304 SUS316 lined with PTFE Common Caliber: DN10 DN15 DN25 DN32 DN40 check valve: to prevent the pipeline liquid does not form a reverse flow. Aka: stop valve Generally vertical installation. Commonly used materials: PVC SUS304 SUS316 lined with PTFE Common Caliber: DN10 DN15 DN25 DN32 DN40 check valve: to prevent the pipeline liquid does not form a reverse flow. Aka: stop valve Built-in stainless steel spring. Commonly used materials: PVC SUS304 SUS316 lining PTFE Common Diameter: DN10 DN15 DN25 DN32 DN40