Product Overview
Resilient seated valve designed for high Cv and low pressure drop
Certified Reliable Valves for Food, Beverage, and Chemical Systems
The 20/21 series resilient seated butterfly valves exceed the high standards required for food and beverage valve applications. Bray’s 20 Series features a wafer body design with flange locating holes; the 21 Series is a lug style suitable for dead-end service.
Food and chemical applications
One-piece disc/stem
High Cv, low pressure drop
Technical Specifications
| Item | Parameter |
|---|---|
| Size Range | NPS 1 to 20 / DN 25 to 500 |
| Body Material | Cast Iron, Ductile Iron, Stainless Steel, Aluminum |
| Temperature Range | -20°F to 400°F (-29°C to 204°C) |
| Stem Material | Stainless Steel, EPDM Molded Stainless Steel, BUNA-N Molded Stainless Steel |
| Maximum Allowable Operating Pressure | 150 psi (10 bar) |
| Seat Material | EPDM, BUNA-N, PTFE Lined EPDM, FKM, Polyurethane |
| Seat Class | Bidirectional Bubble-tight |
| Disc Material | Stainless Steel, EPDM Molded Stainless Steel, BUNA-N Molded Stainless Steel |
| Body Type | Wafer, Lug |
| 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 |
| Testing Standard | MSS SP-61, API 598, EN 12266-1 |
| Certification | ABS, ATEX, Bureau Veritas, DNV, NSF 61/372, PED, PE(S)R, SIL |
| Face-to-Face | MSS SP-67, API 609 Category A, EN 558 |
| Application | Sanitary Service, Mildly Corrosive, Toxic Media |
Features and Benefits
A Stem Bushing
Non-corrosive heavy-duty acetal bushing absorbs actuator side thrust.
B Stem Packing
Dual “U” cup seal design is self-adjusting, providing reliable bidirectional sealing and preventing external substances from entering the stem bore.
C Disc/Stem
One-piece design. The disc edge is spherically machined and hand-polished for bubble-tight sealing, minimum torque, and longer seat life. The disc/stem design inherently prevents particle entrapment and bacterial spoilage, providing the protection required for sanitary applications. For superior corrosion and wear resistance, the one-piece disc/stem is fully encapsulated in EPDM or BUNA-N. The thin-profile disc design provides higher Cv values (up to 50% more than most common stem designs) and enhanced pressure recovery for low pressure drop, resulting in better valve energy efficiency.
D Primary and Secondary Seals
These stem packings prevent pipe media from contacting the stem or body. The primary seal is achieved through interference fit with the molded seat flats on the disc hub. The secondary seal is achieved through a larger stem diameter than the stem hole diameter.
E Seat
Bray’s tongue and groove bonded seat design reduces torque and completely isolates the fluid media from the body. The seat also features a molded O-ring, eliminating the need for flange gaskets.
F Body
Two-piece wafer or lug design simplifies assembly and maintenance. Nylon 11 coating with excellent corrosion resistance is standard for 1”-8” valves and available for larger sizes on request. Polyester coating is standard for 10”-20” bodies.