Model 31 B

Description

The Model 31-B is a compact relief regulator designed expressly for use as a back pressure regulator or bypass valve for controlling inlet pressure between 2 and 16 Inches - W.C. Body is available in cast carbon steel or stainless steel materials only. Interior wetted trims for corrosive applications is standard.

Inlet Design Pressure

• Up to 50 psig (3.44 Barg)

Outlet Pressure

• Up to 50 psig (3.44 Barg)

Line Sizes

• 1/2" (DN15)
• 3/4" (DN20)
• 1" (DN25)
• 1-1/2" (DN40)
• 2" (DN50)

End Connections

• Standard : NPT female
• Option-30: Weld-on 150# RF flanges.
• Option-32: Extended plain end nipples. Use for socket welded piping.
• Option-34: 14" Face to Face Flange Dimension.

Material Combinations: Body / Diaphragm Case / Spring Chamber

• CS/SST/CS
• SST/SST/CS

CS = Cast Carbon Steel 
SST = Cast Stainless Steel 

Features

• Body Material: Carbon steel or stainless steel.
• Trim Material: Choice of four combinations of materials, including 316L SST wetted.
• Setpoint Pressure Range: Multiple springs covering 2.0" - 16.0" W.C. (50 - 400mm H2 O).
• Accurate Regulation: Optimum internals design to ensure rapid response to sudden load changes.
• Multiple Configurations: Valve is factory assembled in four standard positions. Actuator section can be rotated 360° around the valve’s throat. 
• Valve Seat Design: One-piece, molded, resilient seat selflocks, self-aligns, and is easily field maintained. Design minimizes pressure build above setpoint at lockup (no flow) conditions. Buna-N, fluorocarbon elastomer, silicone or TFE seat material. Loading ring allows field adjustment of “boost effect”.