Print Logo
Technical Articles

Hand Operated Shutoff Valves

Series MFR – Hand or Foot Operated/Fail-Safe Spring Return Normally Closed – PVC suitable for Vacuum through 150 PSI




  • No pressure differential required.
    Custom modified valve
  • Max. inlet and/or outlet pressure 150 psi.
  • Compact – requires minimum space.
  • Long dependable cycle life.
  • Low pressure drop with high flow rates.
  • Non-sticking design with bubble-tight sealing.
  • Isolated spring is not in the liquid.
  • Easy to install in any position with 1/4-20 mounting holes supplied.

Plast-O-Matic Series MFR 1/2″ and 3/4″ manually operated normally closed valves are the answer for handling pureliquids, chemicals, acids, and caustics where hand, elbow or foot operation is a prime concern, especially where one hand must be free to do something else — such as holding a part to be rinsed, etc.


Series MFR manual valves require palm, knee, foot, or elbow force to open and close automatically once the force is released due to an internal spring. The stainless steel spring is not in the liquid. Double U-cup seals are used on the internal shaft for low friction and long cycle life. This in conjunction with a poppet seat at the valve orifice results in a non-sticking design. For mounting the valve securely, four 1/4-20 tapered holes are provided in the base of the body. A plastic foam seal under the activating button prevents dirt and dust from entering the top spring area. The valve body, shaft (or “stem”) and button are constructed of Geon® PVC.





1/2″ 3/4″


A 2 3/4 70.0 4 101.6
B 3 76.2 3 1/2 88.9
C 1 3/16 30.2 1 9/16 39.7



CV NPT or BSP Inlet and Outlet
Maximum working pressure* at given temp.

Model Numbers

    @ 77°F (25°C)

@ 140°F (60°C)

3.0 1/2 150 PSI
10 BAR
40 PSI
2,7 BAR
MFR050V (Viton® Seals)
MFR050EP (EPDM Seals)
8.0 3/4 150 PSI
10 BAR
40 PSI
2,7 BAR
MFR075V (Viton® Seals)
MFR075EP (EPDM Seals)