Series-WE31Configuration

Supported Applications

The Dwyer Series WE31 is a full port, 3-way stainless steel ball valve designed for controlling compatible liquids and gases. The series incorporates direct-mounted actuators to create a compact assembly suitable for tight spaces. Limit switches can be mounted directly to the valves to provide remote position indication.

Operating Conditions & Performance

The Series WE31 operates within specific pressure, temperature, and flow parameters defined by its construction:

• Pressure Limits: 28" Hg to 1000 psi (-0.7 to 69 bar)
• Process Temperature Range: -20 to 392°F (-29 to 200°C)
• Ambient Operating Temperatures (Electric Actuators): TD/MD Series: -22 to 140°F (-30 to 60°C); TI/MI Series: -40 to 140°F (-40 to 60°C)
• Ambient Operating Temperatures (Pneumatic Actuators): DA and SR Series: -40 to 176°F (-40 to 80°C)
• Flow Capacity: Cv values range from 11 for the 1/2" size up to 90 for the 2" size.

The valve features a blowout-proof stem, reinforced PTFE seats and seals, and a 316 SS (ASTM CF8M) ball. Electric actuators include thermal overload protection and permanently lubricated gear trains with an 85% duty rating for TD/MD models.

Configuration Options

The Series WE31 is configurable across line sizes, actuator types, control modes, and environmental ratings:

Valve Configuration

• Line Sizes: 1/2" to 2" with Female NPT end connections.
• Wetted Materials: Body and ball: 316 SS (CF8M); Stem: 316 SS; Seat: RTFE/PTFE; Seal, Washer, and Packing: PTFE. O-rings are Fluoroelastomer.
• Valve Positions: Configurable flow paths T1 through L1.

Pneumatic Actuators (DA & SR Series)

• Types: Double acting (DA) and Spring return (SR, rack and pinion).
• Housing Material: Anodized aluminum body with epoxy coated aluminum end caps.
• Air Supply Pressure: DA series: 40 to 115 psi (2.7 to 7.9 bar); SR series normal supply: 80 psi (5.5 bar). Maximum supply pressure is 120 psi (8.6 bar).
• Air Connections: DA01 uses 1/8" female NPT; DA02 to DA04 and SR03 to SR07 use 1/4" female NPT.
• Accessories: NAMUR standard accessory mounting is supported. The SN solenoid valve option electrically switches air supply pressure between ports for opening and closing the spring return actuator.

Electric Actuators (TD/MD & TI/MI Series)

• Housing Material: Powder coated aluminum.
• Enclosure Ratings: TD and MD series are NEMA 4X (IP67); TI and MI series are NEMA 7.
• Control Modes: Two-position actuators drive the valve open or closed using supply voltage. Modulating actuators accept a 4 to 20 mA input for precise positioning.
• Power Supply Options: 110 VAC, 220 VAC, 24 VAC, and 24 VDC (MD models are not available in 24 VDC).
• Cycle Time (per 90°): TD01/MD01: 4 s / 10 s; TD02/MD02: 20 s; TD03/MD03: 30 s.
• Standard Features: Manual override and position indicator. TD models include two limit switches as standard; TI/MI series also feature a position indicator and two limit switches.

Key Product Differences

The Series WE31 distinguishes between actuator families based on power source, environmental protection, and control logic:

• Pneumatic vs. Electric: Pneumatic actuators (DA/SR) utilize air supply pressure for operation, while electric actuators use AC or DC voltage.
• NEMA 4X (IP67) vs. NEMA 7: The TD and MD series provide weatherproof protection rated NEMA 4X (IP67). The TI and MI series are designed for explosion-proof environments with a NEMA 7 rating.
• Two-Position vs. Modulating: Two-position models operate in open/closed states based on voltage application or air pressure direction. Modulating models accept a 4 to 20 mA signal to position the valve at intermediate points between fully open and closed.
• Spring Return Functionality: Spring return pneumatic actuators use internal springs to automatically return the valve to the closed position upon loss of air supply, whereas double-acting models require air pressure for both opening and closing movements.