DFT

In-Line Check Valves

DFT has been making in-line check valves for over 50 years. It started with a customer’s need for a small metal-seated check valve that could be installed in any position while providing tight shut-off. The Basic-Check® valve was developed to satisfy that need. Over the following decades, other customers’ needs led to the development of the DLC®, Excalibur®, GLC®, PDC®, SCV®, and WLC® styles of in-line silent check valves.

Each of these DFT in-line check valves addresses the particular needs of a modern day customer. The DFT silent check valves are known around the world as the valves to use to prevent or eliminate water hammer problems. Whatever your size, pressure or piping configurations, DFT has the valve that’s right for you.

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DFT® Check Valves

DFT, the “Check Valve Doctor” specializes in preventing check valve problems and failures. DFT’s in-line, spring-assisted check valves prevent water hammer and reverse flow. Custom sizing allows DFT to builds check valves to your requirements for horizontal and vertical installations in liquids, gas, or steam applications.

The DFT SCV® model is a corrosion-resistant, dependable, versatile, and economical spring-assisted in-line check valve for a wide range of applications. Whether the fluid is liquid, gas, or steam, the SCV® provides tight shut-off and protects other equipment in the system from water hammer. Its 316 stainless steel construction ensures a long service life.

Specifications:

  • 1/2” – 3” Line Size
  • 750 & 3600 CWP
  • NPT & SW Ends
  • 316 Stainless Steel Construction
  • Inconel® X-750 Spring
  • Spring-Assisted Silent Closing
  • Zelon Body O-ring
  • Horizontal or Vertical Installation
  • Body Guided Disc
  • Tight Shut-Off – Lapped Disc & Seat
  • Simplified Construction – 5 Parts
  • Easy Maintenance
  • Versatile
Threaded Vacuum Breaker

The DFT Vacuum Breaker model provides effective protection against collapse of pressure vessels, tanks, and rolls. They prevent condensate “back-up” when equipment is shut down or inlet steam is reduced by modulating control valves. In piping systems, DFT Vacuum Breakers are used to break siphons, prevent pipe collapse during transient pressure drops, and to provide the addition of air on the downstream side of check valves to dampen water hammer.

Specifications:

  • 1″ – 4″ Line Size
  • 450 to 6000 CWP
  • Threaded Ends
  • Unthreaded Inlet Bore
  • Stainless Steel Construction
  • Spring-Assisted Silent Closing
  • Horizontal or Vertical Installation
  • Tight Shut-Off – Lapped Disc & Seat
  • Easy Maintenance
  • Versatile
Threaded Restrictor Valve

The DFT Restrictor Check Valve (RCV) model is a versatile, all-purpose, spring-assisted, in-line check valve for applications that require higher cracking pressures to open the check valve than those offered by other DFT models. Cracking pressures are available from 2 to 40 psi. Like the Basic-Check® valve, the Restrictor Check provides reliable, low maintenance service for a wide range of fluids and gases at various pressure/temperature combinations. The valve consists of a guard cage, spring, valve disc, retaining ring and seat. It can be combined with pipe fittings such as couplings, drain elbows, etc. (not provided by DFT) to form a complete check valve unit ideally suited for a broad range of applications. The RCV should not be considered a substitute for a Pressure Relief Valve.

Specifications:

  • Higher Cracking Pressure (2-40 psi)
  • 1/4″ – 2-1/2″ Line Size
  • 450 to 2500 CWP
  • Threaded Ends
  • Unthreaded Inlet Bore
  • Stainless Steel Construction
  • Spring-Assisted Silent Closing
  • Horizontal or Vertical Installation
  • Tight Shut-Off – Lapped Disc & Seat
  • Easy Maintenance
  • Versatile
Threaded Basic Check Valve

The DFT Basic Check® Valve model is a versatile all-purpose, spring-assisted, in-line check valve that provides reliable, low maintenance service for a wide range of liquids and gases at various pressure/temperature combinations. The valve consists of a guard cage, spring, valve disc, retaining ring and seat. It can be combined with pipe fittings such as reducing couplings, drain elbows, etc. to form a complete check valve unit ideally suited for a broad range of pipeline applications or incorporated into machinery for OEM applications.

Specifications:

  • 1/4″ – 2-1/2″ Line Size
  • 450 to 6000 CWP
  • Threaded Ends
  • Stainless Steel Construction
  • Spring-Assisted Silent Closing
  • Horizontal or Vertical Installation
  • Tight Shut-Off – Lapped Disc & Seat
  • Easy Maintenance
  • Versatile

The DFT WLC® Wafer style Silent Check Valve model is a lightweight, spring-assisted, center guided, in-line check valve that provides reliable, low maintenance service for a wide range of fluids and pressure/temperature combinations. The joint between the seat ring and body is sealed by the flange gasket upon installation preventing any leakage through the joint when the valve is in service.

Specifications:

  • Wafer Design
  • Lightweight
  • Spring-Assisted Silent Closing
  • Edge Guided (1” & 1-1/2”)
  • Center Guided (2” – 10”)
  • Dual Guided Stem (2” – 10”)
  • Horizontal or Vertical Installation
  • Protected Spring
  • ANSI 150 to 2500
  • 1” to 10” Line Size
  • WCB & 316 SS Bodies
  • 316 SS Trim
  • Ends:
    • Wafer RF
    • Wafer RTJ
  • MSS-SP 61 Seat Leakage
  • API 594 Face-to-Face Dimension:
    • Class 600 RF
    • Class 900/1500 RF

Notes:

1. Soft seats are available for bubble-tight shutoff.
2. Inconel® X-750 spring is available.
3. Excalibur only. Contact DFT for stainless steel or other bolting materials.
4. Corrugated flexible graphite material.

ALC® Wafer Valve

The DFT ALC® Check Valve is a non-slam spring-assisted, center guided “wafer” check valve designed to prevent “water hammer” and “reverse” flow. The lightweight compact design fits between mating flanges and meets API 594 Face-to-Face dimensions. The ALC Check Valve is an easy-to-maintain check valve for applications involving liquids, gases or steam. Tapped holes are provided in the body for lifting lugs to assist with installation (10″ and larger sizes only).

Specifications:

  • API 594 Face-to-Face Dimensions
  • RF Wafer Ends
  • Spring-Assisted Silent Closing
  • Sizes 2″ – 24″
  • Horizontal or Vertical Installation
  • ASME Class 150 and 300
  • Standard Body Materials
    • A216 Grade 216 WCB Carbon Steel
    • A351 CF8M Stainless Steel
  • Stainless Steel Seat, Disc, & Bushing
  • Nitronic 60 Stem
  • Inconel X-750 Spring
  • Seat Leakage to MSS SP-61
  • Tapped Holes in the Body for Lifting Lugs (10″ and Larger)
  • Axial Flow
  • Nozzle Style

Notes:

1. Teflon bushing on 14″,16″, 18″, 20″, and 24″
2. Gaskets used only on valves 10″ and larger
3. 316 SS/Graphite Material

The DFT DLC® model is a corrosion resistant, dependable, versatile and economical spring-assisted, in-line check valve for a wide range of applications. Whether the fluid is liquid, gas or steam, the DLC® provides tight shut-off and protects other equipment in the system from water hammer. Its 316 stainless steel construction ensures a long service life.

Specifications:

  • ANSI B16.10 Face-to-Face Dimensions
  • Spring-Assisted Silent Closing
  • 1/2” – 3” Line Size
  • ANSI 150 and 300
  • 316 Stainless Steel Construction
  • Raised Face Flanged Ends
  • Inconel X-750 Spring
  • Electron Beam Welded Body
  • Meets B16.34 – 1988
  • Horizontal or Vertical Installation
  • Body Guided Disc
  • Tight Shut-Off – Lapped Disc & Seat
  • Simplified Construction – 3 Parts
  • Versatile

Notes:

1. Soft seats are available for bubble-tight shutoff.
2. Inconel® X-750 spring is available.
3. Excalibur only. Contact DFT for stainless steel or other bolting materials.
4. Corrugated flexible graphite material.

GLC® Flanged Check Valve

The DFT GLC® Silent Check Valve model is a spring-assisted, center guided, in-line, flanged check valve that provides reliable, low maintenance service for a wide range of fluids and pressure/temperature combinations. The valve consists of a body, seat, spring, disc with stem and guide bushing. Some valves have body or gasket seals. The DFT GLC® check valve has the advantage of minimum pressure loss with silent, non-slam operation.

Specifications:

  • “Short” Face-to-Face Dimensions
  • One Piece Body
  • Spring-Assisted Silent Closing
  • Center Guided
  • Dual Guided Stem
  • Horizontal or Vertical Installation
  • Protected Spring
  • Easy Maintenance
  • Versatile
  • ANSI 150 to 2500
  • 1” to 24” Line Size
  • WCB & 316 SS Bodies
  • 316 SS Trim
  • RF Flanged Ends
  • MSS-SP61 Seat Leakage

Notes:

1. Soft seats are available for bubble-tight shutoff.
2. Inconel® X-750 spring is available.
3. Excalibur only. Contact DFT for stainless steel or other bolting materials.
4. Corrugated flexible graphite material.

Excalibur® Flanged Check Valve

The DFT Excalibur® Silent Check Valve model is a spring-assisted, center guided, in-line, check valve that provides reliable, low maintenance service for a wide range of fluids and pressure/temperature combinations. The valve consists of a body, gasket, seat, spring, disc with stem and guide bushing. Excalibur® check valves are available in a wide range of sizes and pressure ratings and in a variety of metals to meet most check valve requirements.

Specifications:

  • ANSI B16.10 Face-to-Face Dimensions
  • Spring-Assisted Silent Closing
  • 2” to 24” Line Size
  • ANSI 150 to 1500
  • WCB & 316 SS Bodies
  • 316 SS Trim
  • Ends:
    • RF Flanged
    • RTJ
  • Center Guided
  • Dual Guided Stem
  • Horizontal or Vertical Installation
  • Tight Shut-Off
  • Two-Piece Body
  • Protected Spring
  • Body Gaskets
  • Easy Maintenance
  • Versatile

Notes:

1. Soft seats are available for bubble-tight shutoff.
2. Inconel® X-750 spring is available.
3. Excalibur only. Contact DFT for stainless steel or other bolting materials.
4. Corrugated flexible graphite material.

DFT® Sanitary Check Valves

The DSV® is an in-line spring-assisted check valve designed to prevent flow reversal in industries with strict cleanliness codes. To accommodate various piping arrangements, the DSV® is available as a “Vertical” or “Horizontal” valve.

The DSV®, with a 316L stainless steel body and seat, is fastened with a quick release clamp and elastomeric body seal to permit fast and easy access to the internals. The internal surface finish is 25 Ra while the disc and seat are lapped to provide excellent shutoff.

The DSV® is an in-line spring-assisted check valve designed to prevent flow reversal in industries with strict cleanliness codes. To accommodate various piping arrangements, the DSV® is available as a “Vertical” or “Horizontal” valve. The DSV®, with a 316L stainless steel body and seat, is fastened with a quick release clamp and elastomeric body seal to permit fast and easy access to the internals. The internal surface finish is 25 Ra while the disc and seat are lapped to provide excellent shutoff.

1/2″, 3/4″, 1″, 1-1/2″, 2″ & 3″ 150 CWP, ANSI 108 316L SS body and seat, 316 SS disc, spring and guide assembly, clamped ends, low cracking pressure spring.

The DSV® is an in-line spring-assisted check valve designed to prevent flow reversal in industries with strict cleanliness codes. To accommodate various piping arrangements, the DSV® is available as a “Vertical” or “Horizontal” valve. The DSV®, with a 316L stainless steel body and seat, is fastened with a quick release clamp and elastomeric body seal to permit fast and easy access to the internals. The internal surface finish is 25 Ra while the disc and seat are lapped to provide excellent shutoff.

1/2″, 3/4″, 1″, 1-1/2″, 2″ & 3″ 150 CWP, ANSI 108 316L SS body and seat, 316 SS disc, spring and guide assembly, clamped ends, low cracking pressure spring.