SMC 687 Series Poppet Check Valves

Design Considerations

• The 687 Poppet Check Valve incorporates a thin elastomer disc supported by a poppet

• that seals on the seat

• Pressure in the flow direction moves the seal off the seat at about 1/3 psi before pressure builds enough to move the poppet away from the seat

• Compact design with a light cracking pressure, high flow rate, and a positive seal at very low back pressure or slight vacuum

• An embedded O-Ring Poppet is supplied for cracking pressure applications 1/2 psi and higher

Specifications

Material	Black Glass Filled Polypropylene, White Glass Filled Polypropylene Black PVDF (Kynar®)
End Options	3/4"Female NPT
Seal Option	Buna-N, Ethylene Propylene, Fluoroelastomer (Viton®), AFLAS® *** Please ask us about Seal Materials not listed above. ***
Spring Option: Cracking Pressure and Material	302 Stainless: 1/3 PSI (Disc Poppet), 0.5 PSI (O-Ring Poppet), 1 PSI (O-Ring Poppet), 2 PSI (O-Ring Poppet), 9 PSI (O-Ring Poppet) Hastelloy Spring: 1/3 PSI (Disc Poppet), 0.5 PSI (O-Ring Poppet), 0.7 PSI (O-Ring Poppet), 1.5 PSI (O-Ring Poppet), 3 PSI (O-Ring Poppet), 7 PSI (O-Ring Poppet) No Spring
Maximum Flow Diameter	0.812 in
Cv	12.5 with 3/4"Female NPT Ends
Maximum Operating Pressure	125 PSI
Maximum Operating Temperature	140 °F

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