Gate Valve

Written by Jerry Ratzlaff. Posted in Valve

The gate valve is one of the most frequently used valve in piping systems and is classified as either "rising-stem" or "nonrising-stem" valves.  The rising-stem gate valve has the stem attached to the gate, both gate and stem rise and lower together as the valve handwheel or actuator turns the stem.  In the nonrising-stem gate valves the stem is threaded into the wedge, rising and lowering the wedge.  

It is a multi turn valve which should be used for on and off service. If the valve is partially open as an attempt to throttle or control flow, turbulence from the stream could cause the wedge to vibrate and create a chattering noise.  When fully opened, the gate valve creates minimal obstruction to the flow.

Gate valves control the process through the pipe with a gate.  The gate might be wedge shaped or knife shaped, that slides up or down as the valve's handwheel is turned. As the handwheel is rotated, the gate slides through the valve body to block or release the flow.

Abbreviations

  • GV - gate valve

types of gate valves

Flap Gate Valve

Flap gate is installed at the end of a pipe to prevent back flow of debtis.  When there is flow through a pipe the pressure will open the flap and will close when  pressure is reduced or shut off.

 

Knife Gate Valve

Knife gates are used for handling pulp slurry and other fiberous materials which are extremely thick fluids or dry solids.  The design of the blade allows it to cut through these materials and then clean itself as it is opened.

 

Slide Gate Valve

Slide gates are used when a full bore flow, positive shut-off and low pressure is needed for material handling.  Applications can include dry storage bins, silos and conveyors.

 

Wedge Gate Valve

Wedge gate can be used in most fluids such as air, gas, oil, steam and water for on/off or regulating service. They have a disk that retracts into the body when opened.

 

Gate Valve Datasheets

Face to face dimensions for full and standard port valves is the same.  All ball valves 2" and below are both standard and full port valves.

data flg wedge gate valve 1 data flg knife gate valve 1

standards

API Standards

  • API Spec 6D - Specification for Pipeline Valves, End Closures, Connectors and Swivels
  • API Std 595 - Cast-Iron Gate Valves, Flanged Ends
  • API Std 597 - Steel Venturi Gate Valves, Flanged, Buttwelding Ends
  • API Std 598 - Valve Inspection and Test
  • API Std 600 - Steel Gate Valves, Flanged and Butt-welding Ends, Bolted Bonnets
  • API Std 602 - Steel Gate, Globe, and Check Valves for Sizes NPS 4 (DN 100) and Smaller for the Petroleum and Natural Gas Industries
  • API Std 603 - Corrosion-Resistant, Bolted Bonnet Gate Valve - Flanged and Butt-welding Ends
  • API Std 604 - Ductile Iron Gate Valves, Flanged Ends
  • API Std 605 - Large-Diameter Carbon Steel Flanges (Nominal Pipe Sizes 26 Through 60, Classes 75, 150, 300, 400, 600, and 900)

ASME Standards

  • ASME B16.5 - Pipe Flanges and Flanged Fittings: NPS 1/2 through 24
  • ASME B16.10 - Face to Face and End to End Dimensions of Valves
  • ASME B16.20 - Metallic Gaskets for Pipe Flanges: Ring-Joint, Spiral-Wound, and Jacketed
  • ASME B16.25 - Buttwelding Ends
  • ASME B16.34 - Valves Flanged, Threaded and Welding End

AWWA Standards

  • AWWA C500 - Standard for Metal Seated Gate Valves for Water Supply Service
  • AWWA C509 - Standard for Resilient-Seated Gate Valves for Water Supply Service

BSI Standards

  • BS 1414 - Specification for steel wedge gate valves (flanged and butt-welding ends) for the petroleum, petrochemical and allied industries
  • BS 2080 - Specification for face-to-face, centre-to-face, end-to-end and centre-to-end dimensions of valves
  • BS 5150 - Specification for cast iron gate valves
  • BS 5151 - Specification for cast iron gate (parallel slide) valves for general purposes
  • BS 5154 - Specification for copper alloy globe, globe stop and check, check and gate valves
  • BS 5157 - Specification for steel gate (parallel slide) valves
  • BS 5163 - Specification for predominantly key-operated cast iron gate valves for waterworks purposes
  • BS 5352 - Specification for steel wedge gate, globe and check valves 50 mm and smaller for the petroleum, petrochemical and allied industries

ISO Standards

  • ISO 5996 - Cast iron gate valves
  • ISO 6002 - Bolted bonnet steel gate valves

MSS Standards

  • MSS SP-42 - Corrosion-resistant Gate, Globe, Angle and Check Valves with Flanged and Butt-weld Ends
  • MSS SP-45 - Bypass and Drain Connection Standard
  • MSS SP-61 - Hydrostatic Testing of Steel Valves
  • MSS SP-70 - Cast Iron Gate Valves, Flanged and Threaded Ends
  • MSS SP-80 - Bronze Gate, Globe, Angle and Check Valves
  • MSS SP-81 - Stainless Steel, Bonnetless, Flanged, Wafer, Knife Gate Valves
  • MSS SP-84 - Steel Valves - Socket Welding & Threaded Ends
  • MSS SP-86 - Guidelines for Metric Data in Standards for Valves, Flanges, Fittings and Actuators

gate valve photos