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Brand: Bray International
Bray Series 20/21 Resilient Seated Butterfly Valve
Description
Wafer and lug resilient seated butterfly valves for high Cv, low pressure drop duty
The Bray Series 20/21 is a resilient seated butterfly valve family covering NPS 1 to 20 (DN 25 to 500). Series 20 is the wafer body with flange locating holes; Series 21 is the lug body that allows dead-end service and removal of downstream piping. Bray built the range around a one-piece disc and stem, a thin disc profile that gives a higher Cv and lower pressure drop than most through-stem designs, and a tongue-and-groove seat with a molded O-ring that removes the need for flange gaskets. Bray positions it for food and beverage, chemical, sanitary and mildly corrosive service, and lists NSF 61/372 certification for the family.
Technical specifications
| Parameter | Specification |
|---|---|
| Valve types | Series 20 wafer; Series 21 lug |
| Size range | NPS 1 to 20 (DN 25 to 500) |
| Body materials | Cast iron (A126 Class B), ductile iron (A395 60-40-18), 316 stainless steel (A351 CF8M), aluminum (B26) |
| Disc / stem materials | 316 stainless steel, EPDM or BUNA-N molded over stainless steel; Hastelloy C22 or 17-4 PH on request; one-piece 1 to 12 in., fabricated 14 to 20 in. |
| Seat materials | EPDM, BUNA-N, PTFE lined EPDM, FKM, polyurethane |
| Temperature range | -20 to 400 degF (-29 to 204 degC) |
| Maximum allowable operating pressure | 150 psi (10 bar) |
| Shutoff | Bidirectional, bubble-tight |
| Flange drilling | ASME B16.1 Class 125, ASME B16.5 Class 150, EN 1092 PN 10 |
| Design standards | MSS SP-67, API 609 Category A; face-to-face MSS SP-67, API 609 Category A, EN 558 |
| Testing standards | MSS SP-61, API 598, EN 12266-1 |
| Certifications listed by Bray | ABS, ATEX, Bureau Veritas, DNV, NSF 61/372, PED, PE(S)R, SIL |
| Stem sealing | Double U-cup self-adjusting stem seal with acetal stem bushing |
| Body coating | Nylon 11 standard on 1 to 8 in. bodies; polyester standard on 10 to 20 in. |
Dimensions and weights (metric, sizes 50 to 300 mm)
| DN | A mm | B mm | C mm | D mm | Wafer kg | Lug kg |
|---|---|---|---|---|---|---|
| 50 | 94 | 43 | 51 | 72 | 2.5 | 3.2 |
| 80 | 124 | 46 | 76 | 102 | 3.2 | 4.3 |
| 100 | 154 | 52 | 102 | 131 | 5.0 | 7.2 |
| 150 | 206 | 56 | 146 | 178 | 7.7 | 11.3 |
| 200 | 267 | 60 | 197 | 240 | 14.5 | 20.4 |
| 250 | 324 | 68 | 248 | 291 | 21.3 | 30.0 |
| 300 | 378 | 78 | 298 | 342 | 30.8 | 46.3 |
Dimensions A to D follow the Bray weights and dimensions sheet; sizes 25, 40, 65, 125 and the imperial table are in the attached document. The Technical Sales Manual TM-1050 lists seating and unseating torques, Cv and Kv per disc angle, and flange bolt torques for this series, which are needed to size an actuator and to check capacity.
Selection and what to confirm before ordering
State the line size and flange standard, media and temperature, differential pressure and whether dead-end service is needed (lug), seat and disc material for the fluid, and the operator: lever, gear or actuator with the ISO 5211 mounting top plate. For the 30/31 family see the Bray Series 30/31 butterfly valve; other valves are listed under Control Valves. The 150 psi rating applies to the pressure class; confirm the flange class of the mating pipe before ordering.
Documents and quotation
The attached Bray document gives the Series 20-21 dimensions and weights, sizes 1 to 12 in. (25 to 300 mm). Send size, quantity, body and seat materials and the operator for a quotation.
Datasheets & Documents
- Datasheet Bray Series 20-21 butterfly valves dimensions and weights, sizes 1 to 12 in. Download
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About brand
Bray valves are a familiar sight on water, HVAC and general process lines, mostly as rubber-lined butterfly valves with an actuator bolted on top. Bray International, founded in 1986 in Houston, USA, makes butterfly valves, ball valves and the pneumatic and electric actuators that drive them. Seven Star LLC sources and supplies Bray valves and actuators for plants and building services in Oman, including the Series 30/31 and Series 70 listed here.
Bray valves and actuators listed here
Series 30 and Series 31 are the resilient-seated butterfly valves: Series 30 is the wafer body and Series 31 the lug body. They are used for on/off and throttling duty on water, air and other fluids compatible with the seat. The Series 70 is Bray's electric actuator for quarter-turn valves, ordered by torque size and supply voltage, with on/off or modulating control.
Ordering Bray butterfly valves: what we need
For a valve, send the series, size, wafer or lug body, body, disc and seat materials, flange standard and operator type (lever, gear or actuator). For a Series 70 actuator, send the torque size from the nameplate, voltage, and whether it is on/off or modulating. A nameplate photo covers most of this. GCC water projects often specify the seat and disc materials, so quote them exactly.
Browse Bray International products by category: Control Valves.
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Frequently Asked Questions
What sizes does the Bray Series 20/21 cover?
NPS 1 to 20, equal to DN 25 to 500.
What is the difference between Series 20 and Series 21?
Series 20 is the wafer body; Series 21 is the lug body, which provides dead-end service capability.
What is the pressure and temperature rating?
Maximum allowable operating pressure 150 psi (10 bar) and -20 to 400 degF (-29 to 204 degC), depending on seat material.
Which seat materials are available?
EPDM, BUNA-N, PTFE lined EPDM, FKM and polyurethane.
Does the valve shut off in both directions?
Yes, Bray lists bidirectional bubble-tight shutoff.
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