Pressure Maintaining Valve 200 psi: 1/2 in FNPT

Low pressure maintaining valve, 1/2 in FNPT. Back pressure adjustment range of 0-200 psi (0-14 bar). Pressure can be adjusted by turning the included 378+K control knob/screw assembly.


The 635-200 low pressure maintaining valve produces 0-200 psi (0-14 bar) back pressure. Includes a 378+K control knob/screw assembly for adjusting outlet pressure.


Type Pressure Maintaining Valve
Special Features Low Pressure Outlet
Adjustment Range 0-200 psi (0-14 bar)
Inlet Port Size 1 ea 1/2 in FNPT
Outlet Port Size 1 ea 1/2 in FNPT
Leakage Zero external; ~0.1 SCFM internal
Weight 18 oz (500 g)
Size 5.25 x 2 x 1.5 in
Minimum Temperature -15ºF (-26ºC)
Body Material Anodized Aluminum
Internal Materials Brass 
Seal Materials Viton
Flow Coefficient (Cv) 0.6

Typical Applications

  • Separator and filter systems
  • Compressors
  • Control systems
  • Cascading systems