Idex Standard 1/4-28 Inline Check Valves

Standard 1/4-28 Inline Check Valves

  • Add back-flow protection to any 1/4-28 flat-bottom port
  • 15 psi (1 bar) and 3 psi (0.2 bar) cracking pressure versions
  • Excellent chemical resistance
  • Materials of construction: PEEK™; PCTFE; perfluoroelastomer; PTFE (CV-3301 and CV-3302); stainless steel (CV-3301 and CV-3302); or gold-plated stainless steel (CV-3315 and CV-3316)


Connect these Upchurch Scientific® Inline Check Valves to any 1/4-28 flat-bottom port. Then thread your 1/4-28 flat-bottom fitting into the check valve to connect the tubing. Once installed, the spring-actuated sealing system eliminates back flow, helping to prevent upstream contamination or damage. In addition, the unique design of this product eliminates the additional tubing cuts and connections required to install conventional inline check valves.



Check valves are specified by:

  • Cracking Pressure: the pressure required for the valve to open in the direction of the arrow
  • Maximum Pressure: the maximum pressure the valve can experience in the reverse direction without leaking backwards
  • Back Pressure Created: the amount of back pressure generated by the check valve with 50 mL/min room temperature water flowing in the direction of the arrow


Serial Number



Check Valve Inlet 1/4-28 Male x 1/4-28 Female


Check Valve Outlet Assembly 1/4-28 Male to 1/4-28 Female


Check Valve Inlet Assembly 3 psi 1/4-28 .020


Check Valve Outlet 3 psi 1/4-28 .020 thru hole


Check Valve Inline Outlet