Series WE31 3-Way NPT Stainless Steel Ball Valve

Brand: Dwyer Instruments, LLC

The Series WE31 incorporates a full port 3-way SS ball valve for great flow rates with minimal pressure drop.

The valve features a blowout-proof stem for added safety, reinforced PTFE seats and seals for longer life, and a 316 SS (ASTM CF8M) ball for better performance. Actuators are direct mounted creating a compact assembly for tight spaces.

Limit switches are able to be mounted directly to the valves allowing for remote position indication.

The Series WE31 can be configured with either an electric or pneumatic actuator. Electric actuators are available in weatherproof or explosion-proof, a variety of supply voltages and two-position or modulating control.

Two-position actuators use the supply voltage to drive the valve open or closed, while the modulating actuator accepts a 4 to 20 mA input for valve positioning. Actuators feature thermal overload protection and permanently lubricated gear train.

The pneumatic double acting actuator uses an air supply to drive the valve open and closed. The actuator has two supply ports, with one driving the valve open and the other driving the valve closed.

Spring return pneumatic actuators use the air supply to open the valve, and internally loaded springs return the valve to the closed position.

Also available is the SN solenoid valve to electrically switch the air supply pressure between the air supply ports for opening and closing the valve.

Actuators are constructed of anodized and epoxy coated aluminum for years of corrosion free service.
  • Capable of being configured to fit any application
  • Limit switches can be mounted to manual valves for remote monitoring
  • Vented ball to reduce operating torque
  • Weatherproof or explosion-proof electric actuators
  • Double acting or spring return anodized aluminum pneumatic actuators
  • Full port design reduces the pressure drop across the valve



  • Air Regulator, Instrument Air Filter Regulator

Actuator Type

  • Double-Acting - DA Series
  • Modulating Electric
  • Pneumatic
  • Spring Return - SR Series

Air Consumption

  • 1.5 to 12 scfm (11 to 90 gpm)

Ball Material

  • 316 Stainless Steel

Duty Cycle

  • 85%

Enclosure, Body Material

  • 316 Stainless Steel
  • Anodized Aluminum - DA & SR Series
  • Epoxy Coated Aluminum - DA & SR Series
  • Powder-Coated Aluminum - Electric TD, MD, TI & MI Series

Environmental Protection

  • Explosion-proof: Class I, Groups C & D, NEMA 7, Class II, Groups E, F, G, Division I & II
  • Hazardous Area
  • IP67
  • NEMA 4X
  • NEMA 7

Handle Assembly Material

  • 304 Stainless Steel
  • PVC - Handle Sleeve


  • Position Indicator Lamps


  • 4-20 mA

Materials of Construction

  • 301 Stainless Steel - Washer
  • 304 Stainless Steel - Gland Ring, Locking Device & Stem Nut


  • Compatible Gases
  • Compatible Liquids



NPT Connection

  • 1/2” NPT Female - Electrical Connection
  • 1/4” NPT Female - Air Connections
  • 1/8” NPT Female - Air Connections

O-Ring Material

  • Fluoroelastomer


  • Manual Override

Packing Material

  • PTFE - Wetted Materials


  • Full

Power Requirement

  • 110 Vac
  • 220 Vac
  • 24 Vac
  • 24 Vdc

Pressure Range

  • Inches Hg: -28 to 0
  • psi: 0 to 1,000 (kPa: 0 to 6,900, bar: 0 to 69)

Response Time

  • 4 to 30 seconds

Seat / Seal Material

  • PTFE
  • RTFE (Reinforced Teflon)


  • Line: 1/2” to 3”

Standard Features

  • 3-Way Body

Stem Material

  • 316 Stainless Steel - Wetted Materials

Supply Pressure

  • psi: 40 to 115 (kPa: 270 to 790, bar: 2.7 to 7.9)

Supply Pressure - Maximum

  • psi: 120 (kPa: 827, bar: 8.3)

Switch Quantity

  • Standard Two Limit Switches

Temperature Range

  • -40° to 200° C (-40° to 392° F)

Valve Type

  • Automated
  • Manual

Wetted Materials

  • PTFE - Washer

  • Gas or Liquid Flow Control
  • Ideal for Quick Bubble Tight Shut-Off
  • Mixing or Diverting Liquids and Gases

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