4″ Pneumatic & Hydraulic Operated ASA/ANSI Wet-R-Dri Butterfly Valve

The Betts Wet-R-Dri Valve is a lightweight and compact quarter turn in-line stop valve. This easily maintained and versatile valve is widely used for liquid, gaseous or dry products and is available in a variety of sizes.  This valve comes with an actuator that opens and closes the valve and provides a visual indicator that clearly shows the orientation of the valve disc.  The actuator is available in various styles:

  • Air-open/air-close ASA (model “37”)
  • Air-open/spring-close ASA (model “39”)
  • Spring-open/air-close ASA (model “39” with suffix “017”)
  • Hydraulic-open/spring-closed ASA (model “38”)
  • Spring-open/hydraulic close ASA (model “38” with suffix “017”)

The body is offered in aluminum, cast iron or stainless-lined with coatings available for increased chemical resistance and extended service life.  The actuator is e-coated aluminum with a robust fiberglass cylinder.  The disc seal and shaft O-rings are available in a variety of materials to optimize chemical resistance and service temperature range.  Valve mounts between 125# or 150# ASA/ANSI flanges.

  • Air cylinder max pressure = 150 psig (10 bar)
  • Hydraulic cylinder max pressure = 3,000 psig (207 bar)
  • Actuator max temperature = 240°F (116ºC)


Product Details

Assembly Number Air/Air (Model 17)WeightAssembly Number Air/Spring (Model 19)WeightAssembly Number Hydraulic/Spring (Model 18) WeightBody MaterialDimensionsMaximum Working Pressure
WD437AL*10.6 lbs.
(4.8 kg)
WD439AL*11.2 lbs.
(4.1 kg)
WD438AL*12.2 lbs.
(5.5 kg)
Aluminum A: 13 7/16" (341.3 mm)
B: 7 5/16" (186.3 mm)
C: 2" (50.8 mm)
D: 17" (431.8 mm)
O.D.: 6 5/8" (168.3 mm)
I.D.: 4 3/8" (111.1 mm)
75 psi
(5.17 bar)
WD437GI*12.2 lbs.
(5.5 kg)
WD439GI*12.8 lbs.
(5.8 kg)
WD438GI*13.8 lbs.
(6.3 kg)
Cast IronA: 13 7/16" (341.3 mm)
B: 7 5/16" (186.3 mm)
C: 2" (50.8 mm)
D: 17" (431.8 mm)
O.D.: 6 5/8" (168.3 mm)
I.D.: 4 3/8" (111.1 mm)
75 psi
(5.17 bar)
* Replace asterisk in part number to designate disc coating.

Example Assembly


(4″ Wet-R-Dri Aluminum + White FDA Nitrile)
Seal MaterialsTemperature Range
B = Black Nitrile (Buna-N)-40°F to +240°F (-40°C to +116°C)
WB = White FDA Nitrile (Buna-N)-40°F to +240°F (-40°C to +116°C)
OP = White FDA Nitrile with SS Insert-40°F to +240°F (-40°C to +116°C)
VB = FKM (Viton™ B) Type B+9°F to +400°F (-13°C to +204°C)
VF = FKM GFLT-S-11°F to +400°F (-24°C to +204°C)
V= FKM (Viton™ A) Type A-0°F to +400°F (-17°C to +204°C)
U = Black Urethane-40°F to +200°F (-40°C to +93°C)
E = Black EPDM-50°F to +250°F (-45°C to +121°C)
WE = White EPDM-50°F to +250°F (-45°C to +121°C)
Not all materials are available for every size. Actual temperature values may vary due to service conditions.

Repair Kits and Accessories

Repair Kits Wet-R-Dri Valve

Additional Options

Betts prides itself in being able to provide products that meet a customer’s specific needs. As a result, we do offer modifications to our product standards. While not every request is always feasible, we do our best to meet your specific needs. In many cases, this modification is noted by adding a suffix to the end of the standard part number. The following is a non-inclusive list of common options that are available for this product line. If the options listed below do not meet your requirements please contact one of Betts’ Customer Service Representatives for further assistance. Please note that some product modifications may result in extended lead times.

Installation & Maintenance

Installation: The Wet-R-Dri Valve may be mounted in any position.  Care should be taken when mounting the valve to be sure the I.D. of adjoining flanges or pipe is large enough to allow the disc of the valve to open freely.  Valve mounts between 125# or 150# ASA/ANSI flanges.

Engineering Bulletins

EB-02-17: Wet-R-Dri Valve Product Family Changes and New Product Introduction

SB9-08: Wet-R-Dri Valve Viton® Disc Material Update

EB-01-02: Converting Wet-R-Dri Actuator from Normally Closed to Normally Open

EB3-98: Betts Air Actuator – Manual Operation Instructions