Butterfly Valves Series 20/21. DN 25…500. PN 10/16

Butterfly Valves Series 20
Butterfly Valves Series 20

The Bray sanitary and chemical applications valve. This Bray S20 valve features a onepiece disc/stem. The thin profile, spherically machined hand polished discprovides a very high Cv and greaterpressure recovery plus superior abrasionand erosion resistance in slurry or drymedia applications.

Valve body is covered with epoxy resin resistant corrosion, chemical components. Epoxy coating has a high impact strength.

Specifications

Version: Series 20 - wafer
Series 21 - lug
Pressure nominal PN, Bar: 10/16
Diameter nominal-metric DN, mm: 25…300
Max pressure: 10 Bar for DN25…DN300
Velocity limits: liquids: 9 m/s
gases: 54 m/s
Body: Nylon 11 Coated Cast Iron GG25
Nylon 11 Coated Ductile Iron GGG40.3
ASTM A351 CF8M (EN 1.4408) Stainless Steel
AlSi7Mg Aluminium alloy
Disk: ASTM A351 CF8M (EN 1.4408)Stainless Steel
EPDM Coated stainless Steel
NBR Coated stainless Steel
PTFE Coated stainless Steel
URETHAN Coated stainless Steel
Halar Coated stainless Steel
Stem: ASTM A351 CF8 C)
Buna-N (NBR) (-18...+100 C)
FKM (Viton) (-18...+204 C)
URETHANE (-40...+80 C)
PTFE+EPDM (-29...+121 C)
Actuator: handle / gear operator / pneumatic actuator /electric actuator
Accessories: SS ACTUATOR / positioner / Solenoid valves

Datasheet

 For High Performance in butterfly valve flow control, choose Bray.

SPECIFICATIONS
Bray’s standard product offers valve bodies 25mm-200mm with a Nylon 11 coating, providing excellent corrosion and wear resistance to the valve’s surface – the weakest part of most metal components.

The BODY is two-piece wafer or lug style. Standard bodies are Nylon 11 coated for excellent corrosion resistance. Extended NECK length allows for a minimum of 2" of piping insulation. FLANGE LOCATING HOLES provide quick and proper alignment during instal-lation, thus allowing the installer to center the valve in the pipeline between the flanges.

DISC / STEM (A) One-piece design.The disc edge is spherically machinedand hand polished to produce a bubbletightshut off, minimum torque, andlonger seat life.

STEM BUSHING (B) Non-corrosive,heavy duty acetal bushing absorbsactuator side thrusts.

STEM SEAL (C) Double “U” cup sealdesign is self-adjusting and gives positivesealing in both directions. Preventsexternal substances from entering thestem bore.

NECK (D) Extended neck lengthallows for 50mm of piping insulationand is easily accessible for mountingactuators.

BRAY UNIQUE SEAT DESIGN (E)One of the valve’s key elements isBray’s unique tongue and groove seatdesign. This resilient seat features lowertorque than many valves on the markettoday and provides complete isolationof flowing media from the body. The tongue-and-groove seat to bodyretention method is superior totraditional designs, making fieldreplacement simple and fast. The seat isspecifically designed to seal with sliponor weld-neck flanges. The seatfeatures a moulded O-ring whicheliminates the use of flange gaskets.

PRIMARY AND SECONDARYSEALS (F) The Primary Seal isachieved by an interference fit of themoulded seat flat with the disc hub. TheSecondary Seal is created as a result ofthe stem diameter being greater than thediameter of the seat stem hole. Theseseals prevent line media from coming incontact with the valve stem or body.

BODY (G) Two-piece wafer or lugstyle allows for ease of assembly andmaintenance. Nylon 11 coating forexcellent corrosion resistance isstandard for 25mm-200mm valves andavailable on larger sizes upon request.Polyester coating is standard for250mm-500mm bodies. All valvebodies meet 10 bar pressure ratings forhydrostatic shell test requirements.

BODY BOLTS (H) Standard material is 316 Stainless Steel. AND STEM CONNECTION (I)
Universally designed to ISO 5211 for direct mounting of Bray® power actuators and manual operators. In addition the valves are designed to comply with ISO 5752 face to face and ISO 5211 actuator mounting flanges. Therefore, one valve design can be used in many different world markets. Bray interchangeability and compatibility offers you the best in uniformity of products and low-cost performance in the industry today.

NYLON 11 COATING CORROSION PROTECTION
Bray’s standard product offers valve bodies 25mm-200mm with a Nylon 11 coating, providing excellent corrosion and wear resistance to the valve’s surface – the weakest part of most metal components.
Nylon 11 is a thermoplastic produced from a vegetable base rather than a petroleum base. Nylon 11 advantages include:
1) Excellent Corrosion Resistance – Resists a broad range of chemical environments such as salt solutions, salt water, marine atmospheres, oils, greases and petroleum products. Salt spray tested in excess of 2,000 hours and seawater immersion tested for over 10 years without corrosion to metal
substrates.
2) Abrasion Resistance – very low coefficient of friction, resulting in longer service life and increased performance.
3) Sanitary Applications – inert to fungus growth and moulds, highly stain resistant, USDA Approve d, as well as certified to ANSI /NSF 61 for water service.
4) Outdoor Weathering – resistant to ultra-violet radiation.
5) Impact Resistant – tests have been performed without any peeling of coating.
6) Electrical properties – excellent dielectric properties.
7) Temperature Range – Max: continuous service 93°C  
intermittent service up to 121°C
Min: -29°C (-20°F)

ACTUATORS

 

Due to the modular concept of design, all Bray handles, manual gear operators, and pneumatic or electric actuators mount directly to Bray valves. No brackets or adapters are required..

DIMENSIONS

   Serie 20                                               Serie 21

 

Diameter

 

 

А

 

B

 

C

 

D

 

E

 

F

 Mounting Flange Drig.

 

G

 

H

 

J

 

K

 

L

 

Lug Bolting Data

mm

ins

1+

2+

3+

1+

2+

3+

25

1

60

30

30

44

90

65

50

4

7

10

8

25

11

35

-

-

-

40

11?2

80

32

45

64

105

65

50

4

7

10

8

25

34

35

-

-

-

50

2

94

43

51

72

140

90

70

4

9.5

14

10

32

33

51

125

4

M16

65

21?2

106

46

64

85

152

90

70

4

9.5

14

10

32

49

59

145

4

M16

80

3

124

46

76

102

159

90

70

4

9.5

14

10

32

65

67

160

8

M16

100

4

154

52

102

131

178

90

70

4

9.5

16

11

32

91

87

180

8

M16

125

5

181

56

127

156

190

90

70

4

9.5

19

13

32

118

107

210

8

M16

150

6

206

56

146

178

203

90

70

4

9.5

19

13

32

138

120

240

8

M20

200

8

267

60

197

241

241

150

125

4

14

22

16

32

189

153

295

12

M20

250

10

324

68

248

291

273

150

125

4

14

30

22

50

242

188

350

12

M20

300

12

378

78

298

342

311

150

125

4

14

30

22

50

291

213

400

12

M20

Universally designed to ISO 5211 for direct mounting of Bray® power actuators and manual operators:
Actuator mounting flange ISO recess dimensions:
25mm & 40mm valves F05
50mm - 150mm valves F07
200mm - 400mm valves F12
450mm - 500mm valves F16

EXPECTED SEATING/UNSEATING TORQUES (Nm)

 

Diameter

 

 

А

 

 

B

 

 

C

 

?Р (Bar)

?Р (Bar)

?Р (Bar)

mm

ins

0

3.5

7

10

12

0

3.5

7

10

12

0

3.5

7

10

12

25

1

6.1

6.7

7.3

7.9

8.2

6.7

7.3

8

8.7

9

8.4

9.3

10.9

11

11.3

40

11?2

9.6

10.3

10.8

11.5

11.9

10.6

11.3

12

12.7

13

13.3

14.2

15

15.9

16.3

50

2

12

13

13

14

14

14

14

15

15

16

17

17

18

19

20

65

21?2

19

20

21

22

23

21

22

23

24

25

26

28

29

30

31

80

3

25

27

28

30

31

28

29

31

33

34

35

37

39

41

42

100

4

39

41

44

46

48

42

45

48

51

53

53

58

60

64

66

125

5

58

63

69

75

78

63

69

76

82

85

79

87

95

102

107

150

6

74

83

94

103

107

79

91

103

113

118

98

114

129

141

148

200

8

134

152

170

188

197

147

167

186

206

216

184

208

233

258

271

250

10

213

230

259

288

298

221

253

285

316

332

277

316

356

396

415

300

12

305

351

398

444

467

336

386

437

488

514

419

483

547

610

642

Cv is defined as the volume of water in U.S.G.P.M. that will flow through a given restriction or
valve opening with a pressure drop of one (1) p.s.i. at room temperature. Recommended control
angles are between 25°–70° open. Preferred angle for control valve sizing is 60°–65° open.

 

Cv VALUES–VALVE SIZING COEFFICIENT

ASSEMBLY

For aid in installing the disc/stem into the seat, install a light coat of silicone oil, food grade, onto the top and bottom stem and around the I.D. of the seat. (For silicone free applications use soap and water.) Push the long stem end of the disc/stem into the seat, then push seat over the disc/stem short stem.Place the disc/stem and seat into the upper body half. Align the lower body bolt lugs with the upper body lugs and position lower body in the seat. Replace the body bolts and tighten. Install the stem seal, then the stem bushing.
Replace handle, manual gear box or actuator on actuator mounting flange.
Note: The body halves have a matching casting node on one side only to ensure correct assembly of body halves.

Disc in the Partially Open Position
Disc in the Full Open Position
Disc in the Near Closed Position
 

Technical Information*