Fabri-Valve Figures C37 and F37 are some of the most popular knife gate valve configurations. Figure C37 knife gate valves through 24", feature a heavy duty, rugged one-piece cast body, chest and flanges (except 5", which is fabricated – F37). Sizes larger than 24" are fabricated from heavy plate. The Figure C/F37 is available in all stainless steel (designated "S") or with alloy steel wetted parts and carbon steel external parts (designated "R"). In sizes 1.5” through 24", the "S" and the "R" share the same solid cast body. Sizes larger than 24" feature fabricated bodies configured to the service conditions. The Figure C/F37 is available with the widest range of seats in the industry including: integral metal, replaceable hardfaced metal, rubber "D" ring, replaceable rubber, polyurethane, UHMW-P, and PTFE. Standard body materials include 304, 316, and 317L stainless steel. Special alloys such as 254 SMO® are also available. Special flange drillings are also available.
All Figure C/F37 knife gate valves with handwheels include a provision for a locking device. Consult factory for details.
Unit of Measure


N/A Size Range
Pressure Rating
1.5" - 24": 150 psi (10.3 bar) CWP (cold working pressure)
25" - 48": Designs available in 50 psi (3.5 bar), 100 psi (6.9 bar) or 150 psi (10.3 bar) CWP
Larger than 48": Manufactured to customer specification
Temperature Rating
1.5" -48" 450°F (232°C).
Service temperatures above 400°F (204°C) require high temperature fasteners. Specify service temperature on paperwork. Consult factory for sizes larger than 48" (DN 1200) and for service temperatures up to 1500°F (816°C).
Flange Drilling
ANSI 125/150


N/A Every Fabri-Valve Figure C/F37 valve is fully tested prior to shipment.
Testing includes a body shell test, a seat test and a cycling test to insure proper functioning of moving parts. Additional testing is also available. Please let us know your requirements.
Standard Shell test:

  • Hydro test at 1.5 times the rated CWP (cold working pressure) – Zero allowable leakage
    Standard Seat test:
  • Metal Seat: Hydro test at 40 psi (2.8 bar) and at the rated CWP
  • Resilient Seat: Hydro test at 15 psi (1 bar) and rated CWP

  • Pressure/Temperature Ratings

    N/A The tables listed in 'more images' are the Maximum Pressure/Temperature Ratings for the metallic components only. When checking pressure/temperature ratings, check the temperature rating and chemical compatibility of the packing material and, if applicable, the resilient seat material. In a majority of knife gate valve designs, the temperature limit or the chemical compatibility of the seat and/or packing material determines the practical pressure/temperature limitations.

    * “R” Series valves have external, non-wetted, carbon steel components.
    Standard “R” Series valves are limited to 700°F (371°C); however alternate “R” Series constructions are available to 1000°F (538°C)

    Shutoff Performance

    N/A Metal Seat

  • Single integral metal seat
    1.5" – 24" 40cc / minute / inch of valve size
    25" – 48" 60cc / minute / inch of valve size
    Above 48" Consult Factory
  • Single hardfaced integral metal seat
    1.5" – 24" 80cc / minute / inch of valve size
    25" – 48" 120cc / minute / inch of valve size
    Above 48" Consult Factory
  • Dual metal seats
    Consult factory. All sizes.
  • Single hardfaced replaceable metal seat
    1.5" – 24" 80cc / minute / inch of valve size
    Above 24" Consult Factory
    Resilient Seat
  • Single “D” ring, or single replaceable resilient seat (excluding PTFE)
    Zero leakage. All sizes.
  • Dual seats
    Consult Factory. All sizes.
  • Single replaceable PTFE seat
    Consult Factory. All sizes.

  • Low Pressure Operation

    N/A Metal seated knife gate valves are seat tested at 40 psid (2.8 bar) in the preferred flow direction. When pressure falls below the 40 psid (2.8 bar) test pressure, less force is pushing the gate into the seat, which may result in additional seat leakage. When improved low-pressure shutoff performance is required, optional chest buttons and/or centerline buttons should be specified.

    Available Options


  • "D" Ring Seat
  • Lever Operator
  • Dual Seats
  • Poly Replaceable Seats
  • UHMW Replaceable Seats
  • PTFE Replaceable Seats
  • Rubber Replaceable Seats
  • Hard Faced Replaceable Seats
  • Elastomer Replaceable Seats
  • Hard Faced Gate Edge
  • Hard Gate Material
  • Nickel-TFE Coated Gate
  • Epoxy Coating
  • Thru Drilled Flanges
  • Flush Ports
  • Chest Buttons: Not available 2"-6"
  • Centerline Buttons
  • Backing Ring
  • Extra Wedges
  • V-Port
  • Cast Ni-Hard Deflection Cones
    Available 3"-16"
  • Fabricated Deflection Cones
  • Locking Devices
  • E-Z Spin Handwheel
  • Live Loaded Packing
  • Self-Supporting Yokes
  • Alternate Flange Drilling
  • Bevel Gear
  • Chainwheels
  • Cylinder Actuators
  • Electric Actuators
  • Ratchet
  • Extended Stems
  • Gate Support Strips
  • Rod Boots