687 SERIES CHECK VALVE

Maximum Operating Pressure — 125 psi
Maximum Operating Temperature — 140°F
Seat Area Open Diameter — .812

Design Considerations

The 687 Series 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 first before pressure builds enough to move the poppet away from the seat. The 687 Series Check Valve maximum operating pressure of 125 psi covers a wide range of air and fluid applications. The 687 Check is a compact design with a light cracking pressure, high flow rate, and a positive seal at very low back pressure or slight vacuum. For higher cracking pressure applications, an embedded o-ring poppet is substituted for the standard elastomer disc poppet.

Options

Material Options	Black Polypropylene Body & Poppet White Polypropylene Body & Poppet
Seal Options	Buna-N, Ethylene Propylene, Fluoroelastomer (Viton®), AFLAS (O-Ring Poppet)
End Options	3/4 Female NPT X 3/4 Female NPT
Flow Control Options	302 Stainless Spring - 1/3 psi (Disc Poppet - Standard), 1 psi (O-Ring Poppet), 7 psi (O-Ring Poppet) Hastelloy Spring - 1/3 psi (Disc Poppet), 1 psi (O-Ring Poppet), 3 psi (O-Ring Poppet) No Spring

Example of how to order

Body Material
White Filled Poly

Inlet End
3/4 FNPT

Outlet End
3/4 FNPT

Seal
Viton®

Spring
1/3 psi, Hastelloy

SMC Part Number: WFP CHK 687-12F12F-F,1/3#, HAST

The flow arrow on the body will point from Inlet to Outlet. SMC Part Numbers are a description of the valve as read left to right, Inlet to Outlet.
Example: WFP CHK 687-12F12F-F,1/3#, HAST = 3/4 FNPT Inlet x 3/4 FNPT Outlet

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