Resilient Seated Butterfly Valve

Series 30/31

Manufactured, assembled, and tested in compliance with a written ISO 9001 Quality Assurance Program

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SERIES 30, 31 BUTTERFLY VALVES SERIES 30, 31 BUTTERFLY VALVES

NSF/ANSI 61 Certified Valves for Safe and Reliable Fluid Control

Series 30/31 Butterfly Valves: Proven Bi-Directional Shutoff for Critical Applications

The Bray Series 30/31 resilient seated butterfly valves deliver bidirectional bubble-tight shutoff and long-term reliability for a wide range of fluid handling systems. Designed with a one-piece wafer (30) or lug (31) body, these valves feature a high-strength through stem design and an internal disc-to-stem connection that eliminates leak paths and ensures dependable sealing performance.

- Safety & Certifications: NSF/ANSI 61 and 372 certified for potable           water, CE/PED, SIL, ABS, Bureau Veritas, and DNV approvals.
- Performance: bubble-tight shutoff up to 175 psi (NPS 2–12) and 150       psi (NPS 14–20).
- Applications: potable water, HVAC, desalination, industrial fluid                 systems, and general process isolation.
- Design Benefits: molded O-ring seat, non-corrosive bushings, self-           adjusting stem seal, and no field adjustment required.

With compatibility for ISO 5211 actuators, the Series 30/31 valves are easily automated for on-off or modulating service, making them a trusted solution for safe and efficient fluid handling worldwide.

Specifications

Size Range
NPS 2 to 20 / DN 50 to 500
NPS 14 to 20 / DN 350 to 500
Body Materials
Cast Iron, Ductile Iron, Carbon Steel, Aluminum
Temperature Range
-20°F to 400°F (-29°C to 204°C)
Maximum Allowable Operating Pressure
175 psi (12 Bar)
150 psi (10 Bar)
Stem Materials
Stainless Steel, Monel K500
Shutoff Rating
Bidirectional Bubble-tight
Design Standard
MSS SP-67, API 609, Category A
Flange Drilling
ASME B16.1 Class 125, ASME B16.5 Class 150, EN 1092 PN 10, 16
Testing Standard
MSS SP-61, API 598, EN 12266-1
Certifications
ABS, ATEX, Bureau Veritas, CRN, DNV, FDA 21 CFR 177.1550, NSF 61/372, PED, PE(S)R
Face to Face
MSS SP-67, API 609, Category A, EN 558
Body Style
Wafer, Lug
Seat Materials
BUNA-N, EPDM, FKM, Polyurethane
Disc Materials
Nylon 11 Coated Ductile Iron, Aluminum Bronze, Stainless Steel, Hastelloy®, Halar® Coated Ductile Iron
applications
Potable Water, Wastewater, Seawater, HVAC

Downloads

Technical Sales Manual
Resilient Seated Butterfly Valves

Product Brochure
Resilient Seated Butterfly Valves

IOM Manual
Resilient Seated Butterfly Valves

Safety Manual
Resilient Seated Butterfly Valves

Bolting Guide
Typical Flange Bolting Guide (with washers)

Recommended Specs
Resilient Seated Butterfly Valves Series 30 and Series 31

Weights & Dimensions
Resilient Seated Butterfly Valves Series 30/31

Bolting Guide
Typical Flange Bolting Guide (without washers)

More Details

Features & Benefits

Resilient Seated Butterfly Valve Series 30-31 Features

  • A. Stem Retaining Assembly

    The stem is retained in the body by means of a unique Stainless Steel Spirolox® retaining ring, a thrust washer and two C-rings, manufactured from brass as standard, stainless steel upon request. The retaining ring may be easily removed with a standard hand tool. The stem retaining assembly prevents unintentional removal of the stem during field service.

  • B. Stem Bushing

    Non-corrosive, heavy duty acetal bushing absorbs actuator side thrust.

  • C. Stem Seal

    Double "U" cup seal design is self-adjusting and gives positive sealing in both directions.

  • D. Neck

    Extended neck length allows for 2" of piping insulation and is easily accessible for mounting actuators.

  • E. Disc

    Casting is spherically machined and hand polished to provide a bubble-tight shutoff, minimum torque, and longer seat life.

  • F. Body

    One-piece wafer or lug style. Polyester coating for excellent corrosion resistance. Nylon 11 coating is available as an option.

  • G. Primary & Secondary Seals

    These seals prevent line media from coming in contact with the stem or body. Primary Seal is achieved by an interference fit of the molded seat flat with the disc hub. Secondary Seal is created because the stem diameter is greater than the diameter of the seat stem hole.

  • H. Stem

    Precision double "D" disc to stem connection drives the disc without the need for screws or pins. The close tolerance, double "D" connection that drives the valve disc is an exclusive feature of the Bray valve. Disassembly of the Bray stem is just a matter of pulling the stem out of the disc.

  • I. Seat

    Bray's tongue and groove seat design lowers torque and provides complete isolation of flowing media from the body. The seat also features a molded O-ring which eliminates the use of flange gaskets.

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