Features & Benefits:

Bonnet Isolation
  • The diaphragm isolates the working parts of the valve from process fluids.

    Streamlined Fluid Passage
  • The smooth contoured body has minimal pockets, cavities or dead spaces, which prevent accumulation or stagnation of process fluids or contaminants.

    No Packing Gland or Packing
  • No more packing gland adjustment required or stem packing leakage problems for improved control of fugitive emissions.

    Positive Leak Tight Closure
  • Bubble tight closure is provided in accordance with MSS SP–88.

    In-Line Maintenance
  • Easily maintained when required for reduced downtime and lower cost of ownership.

  • Unique feature in all plastic lined weir valves that prevents liner flexing over the weir, which reduces the potential for liner cracking.

    Molded Closed 2-Piece PTFE Diaphragm
  • Diaphragms are molded to the exact contour of the weir for superior shutoff capabilities.
  • 2-piece configuration eliminates delamination of PTFE which is common to 1-piece configurations.
  • Superior flex life
  • Reduced permeation
  • Excellent chemical resistance

    Adjustable Travel Stop
  • Prevents overclosure of the valve and prolongs diaphragm life. The adjustability feature assures that leak-tight shutoff can be maintained throughout the valve’s life.

    Bronze Bushing
  • Reduces turning torque and enhances cycle life in “dirty” atmospheres.

    Sealed Bonnet
  • Offers secondary process containment to control fugitive emissions.
  • Supplied with leak detection port as standard.

    Floating Tube Nut
  • Prevents point loading of the stud on PTFE diaphragms, which enhances diaphragm life, particularly in high temperature and high cycle applications.

    100% Seat & Shell Testing
  • All valves are pressure tested bubble tight prior to shipment. No visible leakage is allowed.

    Extensive selection of body and diaphragm materials and actuation packages.
  • Allows optimum selection of materials for service conditions, often without expensive upgrades.
  • Unit of Measure

    Technical Data


    N/A ITT Dia-Flo

    Weir Valve Selections

    N/A Unlined Metal

    • Excellent Cv’s
    • Complete Selection of End Connections
    • ASTM Materials Include:
      • Cast Iron ASTM A-126 Class B
      • Ductile Iron ASTM A-395 Grade 60-40-18
      • Cast Steel ASTM A-216 Grade WCB
      • 316 Stainless Steel ASTM A-351 Grade CF8M
      • 316L Stalinless Steel ASTM A-351 Grade CF3M
      • Bronze ASTM B62 Alloy 836
      • Alloy 20 ASTM A-351 Grade CN7M
      • Hastelloy C ASTM A-494 Grade CW-6M
      • Monel ASTM A-494 Grade M-35-1
      • And More
    Maximum temperature for all unlined configurations is 350°F (177°C) but may decrease depending on media, pressure and valve size.

    Rubber Lined Bodies
    • 1/8" Minimum Lining Thickness
    • Ductile Iron or Cast Iron Available
    • Full Flat Faced Flange Lining
    • Excellent for Abrasive Applications
    Lining Materials:
    • Neoprene...A synthetic base elastomer with some physical properties similar to natural rubber. Superior to natural rubber in resistance to heat, ozone, sunlight and oil. Typical applications include: phosphoric acids; magnesium oxide and sodium hydroxide. Maximum temperature 200° F (93° C)
    • Soft Rubber...Good resistance to most inorganic chemicals with the exception of strong oxidizing agents. Exhibits outstanding abrasion resistance. Typical applications include: gypsum, flyash, titanium dioxide slurries and sewage. Maximum temperature 180° F (82° C)
    • Hard Rubber…Better chemical and heat resistance than soft rubber. Wide application in organic and inorganic acids and chlorine gas. Typical applications include: potable water; oxidizing agents; plating solutions; salts; sludge and ferric chloride. Maximum temperature 200° F (93° C)
    • Hypalon…Good resistance to high concentrations of sulfuric and nitric acids. Good heat, weather, ozone and abrasion resistance. Other typical applications include: nickel plating solutions and ferric chloride. Maximum temperature 200° F (93° C)
    • Chlorobutyl…Good heat resistance. Unaffected by cold weather or rapid temperature changes. Typical applications include: hydrofluoric acid, various zinc solutions and fertilizer solutions. Maximum temperature 200° F (93° C)
    Plastic Lined
    • 3/16" Minimum Lining Thickness*
    • Superior Flow Capabilities
    • Line-Lok feature
    • Wide Selection of Lining Materials
    *Lining thickness of PFA is .14” minimum.

    Line-lok is a unique feature of Dia-Flo diaphragm valves. As can be seen by the drawing below, the weir area is locked firmly to the body eliminating flexing of lining during valve cycling, which can lead to premature liner failure.

    Lining Materials:
    • Excellent chemical resistance to all common solvents, superior high purity resistance, excellent temperature resistance. Maximum temperature 350° F (177° C)
      ETFE (Tefzel)
    • Suitable for strong acids and solvents. Compatible with a very broad range of chemicals under a wide range of conditions. Maximum temperature 300° F (149° C) Note Tefzel is a registered trademark of E.I. DuPont de Nemours and Co. Inc.
    • Especially suitable for organic solvents degreasing agents, excellent resistance to alkalines...economically priced, poor resistance to chlorinated solvents. Maximum temperature 200°F (93° C)
    • Very good corrosion and chemical resistance, performs well in many applications at elevated temperatures. Maximum temperature 285° F (140° C)
    • Very good corrosion and weather resistance…note that temperatures may be restricted. Maximum temperature 140° F (60° C)
    Solid Plastic
    • Lightweight and economical
    • Excellent interior/exterior corrosion resistance
    • Body materials include:
      PVC (Polyvinyl chloride)
      CPVC (Chlorinated polyvinyl chloride)
      PVDF (Polyvinylidene fluoride)
    The body of the Dia-Flo plastic diaphragm valve is available in a variety of high-performance engineered polymers including polyvinyl chloride (PVC), chlorinated polyvinyl chloride (CPVC), polypropylene (PP), and natural polyvinylldene fluoride (PVDF). The bonnet is manufactured from glass-reinforced polymers: either PP (polypropylene) or, for high temperature service, PAS (polyarylsulfone). An optional PAS pneumatic actuator is also available.

    ANSI B16.10 Face-to-Face

    Improve performance for Active Pharmaceutical Ingredients (API) and chemical process customers by replacing ball and plug valves. The Dia-Flo diaphragm valve with ANSI B16.10 face-face dimensions offers all of the advantages of diaphragm valves and is a direct replacement for ball and plug valves without the need for piping modifications.

    As with all other diaphragm valves this valve offers these clean service benefits:
    • Can be cleaned in place without disassembly or removal from the pipeline;
    • Has no cavities or pockets to trap process or cleaning fluids;
    • Is available in FDA Compliant Materials;
    • Is available with stainless steel exterior to eliminate contamination potential from chipping paint;
    • Can be steam sterilized
    Also suitable for corrosive and abrasive applications the ANSI face-to-face diaphragm valve offers:
    • A smooth flow path for media resulting in less damage to the valve body and diaphragm;
    • No ball or plug to become damaged by abrasive media;
    • A large sealing surface provided by the diaphragm;
    • No cavities or pockets for process fluid to become trapped;
    • Available sizes 1”, 11/2” and 2”
    • Bodies available in - Stainless steel lined with PFA;
      • Ductile iron lined with PFA
      • Stainless steel unlined
    • Bonnet assemblies available - Stainless steel or ductile iron, hand wheel operated or automatic operation
    Diaphragm Materials

    The diaphragm material and design are integral to the successful performance of the diaphragm valve. For that reason, 10 weir elastomer diaphragms and 2 weir PTFE diaphragms are available to handle a multitude of process fluids and parameters.

    Elastomer Diaphragms
    Grade Material (FDA Compliant) Size Temperature Typical Services
    Grade B Black Butyl (FDA Compliant) ½-12" -20 to 250°F (-29 to 121°C) Chemicals, gases, stronger acids
    Grade W1 White Butyl (FDA Compliant) ½-6" 0 to 225°F (-18 to 107°C) Foods, beverages, pharmaceuticals
    Grade 17 EPDM (FDA Compliant) ½-8" -30 to 300°F (-34 to 149°C) Beverages, pharmaceuticals
    Grade M EPDM ½-12" -30 to 300°F (-34 to 149°C) Chemicals, acids, hi-temp, abrasives
    Grade C Hypalon® CSM ½-12" 0 to 225°F (-18 to 107°C) OxidiIng fluids, oil resistant
    Grade S Natural Rubber ½-8" -30 to 180°F (-34 to 82°C) Water, abrasives
    Grade T Neoprene® ½-12" -20 to 200°F (-29 to 93°C) Weak chemicals, air, oil resistant
    Grade DP Buna N® NBR (FDA Compliant)
    Direct Loaded Valve only
    ½-3" 10 to 180°F (-12 to 82°C) For direct load valve only
    Grade P Buna N® NBR (FDA Compliant) ½-12" +10 to 180°F (-12 to 82°C) Foods, oils
    Grade V Viton® FKM ½-6" -20 to 325°F (-29 to 163°C) Specific solvents & chemicals, oils

    Our elastomer diaphragms are available in a variety of materials to address various process characteristics. Some elastomer diaphragms are softer and better suited to abrasive and slurry applications. Others are harder, providing greater chemical resistivity and higher temperature limitations. All elastomer diaphragms in sizes 1" - 8" are molded in the closed position to provide the most effective seal. Each diaphragm contains markings identifying the size, material, mold date and diaphragm supplier.
    • The molded closed design increases the sealing properties of the diaphragm. The relaxed position of the diaphragm is contoured to the same shape as the weir which increases the ability of the diaphragm to provide a bubble-tight shut-off.
    Due to diaphragm area limitations, sizes smaller than 1” are molded open.

    Diaphragm Traceability
    All diaphragm materials and physical properties are batch traceable via permanent codes molded into the diaphragm tabs. The molding date, material type, and diaphragm size provide traceability to original batch records.

    PTFE Diaphragms
    Grade Material (FDA Compliant) Size Temperature
    Grade TM Modified PTFE (FDA Compliant) ½-6" -30 to 350°F (-34-177°C)
    Grade R2 PTFE (FDA Compliant) 8"-10" -30 to 350°F (-34-177°C)

    The two-piece PTFE (Polytetrafluoroethylene) diaphragm assembly utilized in the Dia-Flo diaphragm valve has proven through years of outstanding service to be the best design available. The two-piece construction, consisting of PTFE diaphragm and ethylene propylene elastomer backing cushion, fully eliminates the problem of delamination permeational cracking common to competitive “PTFE-faced” designs.

    To ensure the best possible diaphragm, ITT maintains a continuing development program to utilize new materials and improve existing compounds. The result of this effort is the recent introduction of the PTFE grade TM diaphragm (1/2-6”).

    Proven benefits of the PTFE grade TM diaphragm versus conventional PTFE diaphragms are:
    • Reduced permeation due to a more homogeneous microstructure with minimal voids
    • Reduced cold flow similar to 25% carbon reinforced PTFE
    • Increased cycle life due to a more amorphous compound
    The floating tube nut feature contributes largely to the successful operation of plastic diaphragms in Dia-Flo diaphragm valves. The downward force of the stem is transferred to the compressor, by-passing the tube nut. The result is that forces are evenly distributed over the seating area of the diaphragm, thus reducing cold flow and stud pull out concerns. This design is also used on 6" and larger elastomer diaphragms.

    Manual Bonnet Assemblies

    Dia-Flo diaphragm valve bonnet assemblies are equipped as standard with:
    • Bronze Stem Bushing
    • Molded-in Fingers*
    • Grease Fitting** (6-12”)
    • Thrust Bearing Visual Position Indication
    • Adjustable Travel Stop (1/2-4”)
    • Permanently Sealed Lubrication (1/2-4”)
    • Clear Stem Cover (1/2-4”)
    *In conjunction with the compressor, the fingers positively support the diaphragm from the closed to open position. The diaphragm is lifted high when the valve is opened and is pressed tightly against the weir when the valve is closed. It is supported in all positions by alternate fingers of the compressor and bonnet. Fingerplates in place of molded in fingers are utilized in 3” through 6” stainless steel bonnet assemblies.
    ** Not used with sealed bonnet