SERIES 31H/36H Heating, Ventilating & Air Conditioning (HVAC) - High Pressure

Product catalog summary

Introduction
Bray Controls offers high-quality manual butterfly valves designed for HVAC applications. The Series 31H and 36H valves are engineered for high-pressure environments, with the Series 31H rated for 250 psi and the Series 36H for 150 psi.

Features

Valves are compatible with ANSI Class 125/150 flanges and are bidirectional, tested to 110% of their pressure rating.
The Series 31H features a unique double “D” connection that eliminates exposed stem retention components, reducing leak paths and corrosion.
Disc casting is spherically machined for a bubble-tight shut-off with minimal torque.
Patented retaining rings ensure a blow-out proof stem.
The seat design is bonded with aerospace adhesive, providing a complete seal and isolating the valve interior from the line media.
Non-corrosive bushings and self-adjusting packing glands enhance durability and performance.

Specifications

Pressure Ratings: 2"-20" valves are rated at 250 psi, while 24" valves are rated at 150 psi.
Temperature Range: Seats can withstand temperatures from -40°F to 250°F.
Velocity Limits: Fluids at 30 ft/sec and gases at 175 ft/sec.

Materials

Body: Cast Iron, ASTM A126 Class B
Disc: Aluminum Bronze, ASTM B148-954
Stem: Type 416 Stainless Steel, ASTM A 582
Seat: EPDM

Installation and Maintenance
Refer to Bray Technical Bulletins 1071 and 1114 for detailed installation and maintenance instructions for Series 31 and 36 valves, respectively.

Cv Values and Valve Sizing
Cv is defined as the volume of water in U.S.G.P.M. that flows through a valve with a 1 psi pressure drop at room temperature. Recommended control angles are between 25°–70° open, with a preferred angle of 60°–65° for control valve sizing.

Dimensions and Standards
The Series 31H and 36H valves meet ISO 5211 standards for mounting flanges, allowing direct mounting of Bray manual operators. Bray Controls is ISO 9001 certified.