CONTROLS
A Division of BRAY INTERNATIONAL, Inc.
Resilient Seated Butterfly Valves
Technical Manual
TM1050 - 10/30/2012
Resilient Seated
Butterfly Valves
Technical Manual - Table of Contents
Topic Page(s)
Introduction to Torques ........................................3
Reduced Disc Diameter Bray Valves 30/31/3A ..6
Seating & Unseating Torques .............................. 7
20/21, 30/31 Imperial (Lb-Ins) ...............................8
20/21, 30/31 Metric (N-m) ....................................9
32/33, 35/36 .........................................................10
Imperial (Lb-Ins) & Metric (N-m)
22/23 Imperial (Lb-Ins) & Metric (N-m) ................11
Dynamic Torque Factors
Imperial (Lb-In/psi) ................................................12
Metric (N-m/bar) ................................................... 13
Valve Sizing Coefficients .................................. 14
Imperial (Cv) ......................................................... 15
Metric (Kv) ............................................................ 17
Flange to Valve Bolting Guide ............................. 19
Flange Bolt Tensioning Data ................................ 20
Standard Metal Specifications
20/21 & 22/23 .......................................................23
30/31, 31H, 3A/3AH, 31U ......................................24
32/33, 35/36, 35F, 36H .......................................... 25
All statements, technical information, and recommendations in this bulletin are for
general use only. Consult Bray representatives or factory for the specic requirements
and material selection for your intended application. The right to change or modify
product design or product without prior notice is reserved.
Resilient Seated Butterfly Valves – Torques
Torques
INTRODUCTION
There are a number of torques which buttery valves may
experience such as:
Tsu - Seating and Unseating Torque
Td - Dynamic Torque Resulting from uid ow
T
– Bearing Friction Torque
bf
Tss – Stem Seal Friction Torque
Te – Eccentricity Torque resulting from
disc offset from centerline of stem (either single,
double or triple offset)
Th – Hydrostatic Torque
Factors which inuence the buttery valve torque values
shown above are:
Type of Seat and Seat Material
Interference of Seat I.D. and Disc O.D.
Shaft Diameter
Valve Diameter
Bearing Coefcient of Friction
Angle of Opening
Shut-off Pressure
Fluid Velocity
Disc Shape and Conguration
Piping System and Location/Orientation of Valve in Pipe Line
System Head Characteristics
Physical Size of Disc/Shaft Obstructing Flow
Disc Edge Finish
With respect to Buttery Valves, the two major conditions for
determining total valve operating torque (TT) exists as follows:
CASE I (Angle = 0° , Disc in Closed Position)
TT = Th + Tbf + Tss+ T
Analyzed
Total Torque for Case I using a symmetrical disc buttery valve is
the sum of hydrostatic torque, bearing friction torque, stem seal,
friction torque, and seating/unseating torque.
A. Hydrostatic Torque (Th)
We will ignore discussion of the hydrostatic torque values as they
are generally insignicant compared to the seating/unseating,
bearing friction and stem seal torque values (the safety factor
applied to seating/unseating, stem seal friction and bearing
friction torque values more than compensates for the hydrostatic
torque which is usually less than 2% of these total torques).
B. Bearing Friction Torque (Tbf)
Bearing friction torque occurs because pressure forces against
the disc are transmitted to the stem. As the stem is forced against
the bearing supports, bearing friction torque is created between
the stem material and the support material as the stem is turned.
Bearing friction torques are normally included in the seating/
unseating torque values.
Bearing friction torques can be determined by using
the following equation:
Tbf = .785 Cf D
Where:
Tbf = Bearing Friction Torque
Cf = Coefcient of Friction (approximately .25 for non-
corroded stem to cast iron body) (dimensionless).
Dv = Valve Diameter (Inches)
d = Diameter of Shaft (Inches)
∆P = Pressure Differential (psi)
su
2
(d/2) ∆P
v
Introduction : 3
C. Stem Seal Friction Torque (Tss)
For all practical purposes stem seal friction torque values are
insignicant when compared to seating/unseating and bearing
friction torques. Stem seal friction torques are normally included
in the seating/unseating torque values.
All information herein is proprietary and condential and may not be copied or reproduced without the expressed written consent of BRAY INTERNATIONAL, Inc.
The technical data herein is for general information only. Product suitability should be based solely upon customer’s detailed knowledge and experience with their application.
Resilient Seated Butterfly Valves – Torques
D. Seating/Unseating Torques (Tsu)
The seating/unseating torque value (Tsu) is a function of the
pressure differential, the seat material’s coefcient of friction,
the nished surface of the disc edge, the amount of interference
between the seat I.D. and disc O.D. when anged in piping, the
seat thickness, and the type of service (media) for which the valve
is being used. In determining the Tsu values for Bray resilient
seated buttery valves, Bray has developed Seating/Unseating
Torque Charts incorporating all bearing friction and stem seal
friction torques for three classes of services for both the valves
with standard discs (rated to full pressure) and for valves with
reduced diameter discs (rated for 50 psi [3.5 bar]). The three
service classes are:
Class I – Non-Corrosive, Lubricating Service
Class II – General Service
Class III – Severe Service
Please review the guidelines for each class in the technical
manual when determining which Seating/Unseating Torque Class
should be used. Most buttery valves are used in Class II, General
Service applications.
E. Total Torque (TT)
The total torque values for Bray symmetrical disc valves for Case
I applications are shown in the Seating/Unseating Torque Charts
within this manual.
CASE II
(Disc in Partial To Full Opening Position)
TT = Tbf + Tss+ T
d
The total Torque for Case II using a symmetrical disc buttery valve
is the summation of bearing friction torque, stem seal friction torque
and dynamic torque.
A. Bearing Friction Torque (T
)
bf
See Case I discussion. This torque value is normally included in
the Dynamic Torque Value.
B. Stem Seal Friction Torque (Tss)
See Case I discussion. This torque value is normally included in
the Dynamic torque value.
C. Dynamic Torque (Td)
In a symmetrical disc design, dynamic torque occurs between the
closed position, 0° and the full open position, 90°. With the disc in
the partially open position, velocity of the uid passing the leading
disc edge is less than the velocity passing the trailing edge. This
variance in velocity past the leading disc edge and trailing disc
edge results in an unbalanced distribution of pressure forces on
the upstream side of the face of the disc. The total pressure forces
acting perpendicular to the disc face on the leading edge half of
the disc are greater than the total pressure acting perpendicular on
the trailing half of the disc. This uneven distribution of pressure on
the disc face (exists on both sides of the disc) results in a torsional
force which tries to turn the disc to the closed position (Figure 1).
This torsional closing force can become greater than the seating/
unseating torque value depending on the valve angle of opening
and differential pressure.
To determine dynamic torque, the following equation is applied:
T
= C
d
3
d
∆P
dt
Where:
Td = Dynamic Torque (lbs- in).
Cdt = Coefcient of Dynamic Torque (based on disc shape
and angle of opening) (dimensionless)
d = Diameter of Disc (Inches)
∆P = Pressure Differential Across Valve (psi)
Introduction : 4
Figure 1 - Pressure Distribution
C
l
o
Pressure Forces
FLOW
All information herein is proprietary and condential and may not be copied or reproduced without the expressed written consent of BRAY INTERNATIONAL, Inc.
The technical data herein is for general information only. Product suitability should be based solely upon customer’s detailed knowledge and experience with their application.
s
i
n
g
T
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MORE
TURBULENCE
HERE
Resilient Seated Butterfly Valves – Torques
As shown in Figure 2, dynamic torque for Bray’s symmetrical disc
valves is at 0° angle of opening and increases until the angle of
opening reaches 75°-80°, where it then decreases to a zero value
at full open (90°) (no internal friction factors considered, just
dynamic torque only).
One nal comment about dynamic torque is that one may minimize
the dynamic torque by the orientation of the valve (stem horizontal
or vertical) in the pipeline as well as by the location (distance) in
the pipeline from elbows, other valves, etc. (See Bray Resilient
Seated BFV Operations and Maintenance Manual).
D. Total Torque (T
)
T
The total torque required for operating a Bray symmetrical disc
buttery valve at an angle opening between 0°and 90° is shown in
the Dynamic Torque section of this manual. Note that the dynamic
torque includes all internal friction torque values.
Figure 2 - Angle of Opening
The Cdt value for Bray symmetrical disc valves are approximately:
CONCLUSION
In most applications for buttery valves, especially 20˝ (508mm)
or smaller, the maximum torque required to operate the valve will
be seating/unseating torque. However, dynamic torque should be
considered particularly in:
• Control applications using larger valves (24˝ [610mm] and
above) where the disc is maintained in the open position
• Applications using larger valves (24˝ [610mm] and above)
where the velocity is high (16 ft./sec [5.3m/sec]).
Angle of
Opening
C
dt
0° 10° 20° 30° 40° 50° 60° 70° 75° 80° 90°
0 0.0126 0.0140 0.0251 0.0505 0.0809 0.1394 0.2384 0.3419 0.401 0
Introduction : 5
All information herein is proprietary and condential and may not be copied or reproduced without the expressed written consent of BRAY INTERNATIONAL, Inc.
The technical data herein is for general information only. Product suitability should be based solely upon customer’s detailed knowledge and experience with their application.
Resilient Seated Butterfly Valves – Torques
Reduced Disc Diameter
Bray Series 30/31/3A Valves
Bray offers a reduced disc diameter for 4”-20” for Series 30, 31
and 3A valves. The purpose of reducing the disc diameter is to
decrease the seating/unseating torques and extend the seat life on
low pressure applications.
By reducing the disc diameter, the interference between the disc
O.D. and seat I.D. is decreased and the valve pressure rating,
which is a function of this interference, is reduced to 50 PSI. Less
interference between the disc and seat results in reduced seating/
unseating torques. Lower seating/unseating torque may allow for
the use of a smaller actuator on the valve. In other applications
where abrasive dry bulk materials such as cement, sugar, plastic,
pellets, our, etc., are generally pneumatically conveyed at 50
PSI or less, the reduced disc diameter not only reduces the seat-
ing/unseating torque but, very importantly, usually signicantly
increases the service life of the seat.
Bray does the following to differentiate reduced diameter discs
from full diameter discs:
Metal Discs: An “ R ” is stamped above the part number
Nylon 11 Coated Discs: Discs are differentiated by the color of
the Nylon 11:
Grey – Full Disc Diameter
White – Reduced Disc Diameter
Introduction : 6
All information herein is proprietary and condential and may not be copied or reproduced without the expressed written consent of BRAY INTERNATIONAL, Inc.
The technical data herein is for general information only. Product suitability should be based solely upon customer’s detailed knowledge and experience with their application.
Resilient Seated Butterfly Valves – Seating & Unseating Torques
Seating & Unseating Torques
Bray has developed Seating/Unseating Torque Charts for three
Classes of Service for its valves with standard discs (rated for
full pressure) and for valves with reduced diameter discs (rated
for 50 PSI / 3.5 bar.).
Characteristics of
Application
Media Type
Corrosion
by Media
Chemical
Reactions of Media
with Seat
Media
Temperature
Non-Corrosive, Lubricating Service
Class A
Lubricating hydrocarbons;
Aqueous processes and Water
(See Note 1)
Insignificant if any
Insignificant if any
45º to 160ºF
(7º to 71ºC)
The guidelines for selecting a Class to be used for determining
a valve’s seating/unseating torque are given below. Each valve
application should comply with all ve Class characteristics in
order to be qualied for that Class.
Class B
General Service
Water; aqueous processes; all
other aqueous liquids including
salt water; Lubricating gases
No major corrosion or deposits
from media
Only minor or insignificant in
nature
Within seat temperature limits,
not near limits
Dry, non-lubricating such as air,
Reactions causing swelling and
Class C
Severe Service
dry gas, cement, pneumatic
conveying mediums
Can incur significant
corrosion such as Ductile Iron
disc in water
hardness occur
Near or at seat temperature
limits
Frequency of
Valve Cycling
Once weekly or more frequently
NOTE:
1. For aqueous processes and water, Class A torques may be
used only if a Nylon 11 coated disc is selected and all other
Class A characteristics apply. Otherwise, Class B torques
should be used.
2. All the material trims may be classied into Class A, B, or
C except Series 20/21 valves with a PTFE Lined Elastomer
seat, PTFE molded disc/stem, or rubber molded disc/stem.
These trims must always use Class C Seating/Unseating
Torque Values unless they are used only in a throttling
application. Valves with bonded seats must always be
classied as Class C.
3. If a valve is used strictly in a throttling application, that is,
it is never put in the closed position but throttled between
20° and 80°, then Class A torques may be used provided
you have checked to see that dynamic torques do not
exceed the Class A torque values.
Minimum once every 3-6 weeks,
or more frequently
Infrequently, sometimes not
cycled for long periods
4. With the exception of dry, non-lubricating medias, one
is usually safe electing to use Class B torques for sizing
actuators for all other valve service applications. Seating/
Unseating Torque values shown include friction bearing
torques for stated differential pressure.
5. Dynamic Torque values are not considered.
See the Dynamic Torque chart in this manual for
determination of Dynamic Torque.
6. Do not apply a safety factor to torque values when
determining actuator output torque requirement.
7. For 3-way assemblies where one valve is opening and
another is closing, multiply torque by a 1.5 factor.
Torque : 7
All information herein is proprietary and condential and may not be copied or reproduced without the expressed written consent of BRAY INTERNATIONAL, Inc.
The technical data herein is for general information only. Product suitability should be based solely upon customer’s detailed knowledge and experience with their application.
Class A
Non-Corrosive,
Lubricating
Service
Valve
Size
Inches
1
1.5
2
2.5
3
4
5
6
8
10
12
14
16
18
20
Resilient Seated Butterfly Valves – Seating & Unseating Torques
Series 20/21 and 30/31/3A Torques (Lb-Ins)
Valve Differential Pressure (PSIG)
Full Disc Reduced Disc
0 psi 50 psi 100 psi 150 psi 175 psi 0 psi 50 psi
54 59 65 70 73 54 59
81 86 91 97 100 81 86
109 114 119 123 128 109 114
169 178 187 196 200 169 178
220 236 250 264 273 220 236
341 364 387 410 423 225 248
510 560 610 660 687 324 374
632 712 792 872 912 344 488
1,182 1,341 1,500 1,660 1,741 735 894
1,764 2,018 2,272 2,526 2,653 1,204 1,358
2,701 3,110 3,519 3,928 4,132 1,665 2,074
3,818 4,500 5,182 5,864 –– 2,318 3,000
4,638 5,819 7,000 8,182 –– 2,699 3,880
5,265 7,065 8,865 10,665 –– 2,970 4,788
7,000 9,364 11,728 14,091 –– 3,356 6,243
Class B
General Service
Class C
Severe Service
1.5
2.5
10
12
14
16
18
20
1.5
2.5
10
12
14
16
18
20
1
2
3
4
5
6
8
1
2
3
4
5
6
8
59 65 71 77 80 59 65
89 95 100 106 110 89 95
120 125 130 135 140 120 125
185 195 205 215 220 185 195
245 260 275 290 297 245 260
375 400 425 450 462 252 267
560 615 670 725 755 355 410
695 783 871 953 1,003 427 537
1,300 1,475 1,650 1,825 1,915 808 983
1,960 2,240 2,520 2,800 2,940 1,213 1,493
2,970 3,420 3,870 4,320 4,545 1,830 2,280
4,200 4,950 5,700 6,450 –– 2,550 3,300
5,100 6,400 7,700 9,000 –– 2,967 4,267
5,850 7,850 9,850 11,850 –– 3,267 5,267
7,700 10,300 12,900 15,500 –– 4,267 6,867
74 82 89 97 100 74 82
111 119 125 133 137 111 119
151 157 163 169 175 151 157
231 244 257 269 275 231 244
306 325 344 363 375 306 325
468 500 532 563 582 316 348
700 769 838 907 944 444 513
870 980 1,090 1,200 1,255 525 672
1,625 1,844 2,063 2,282 2,394 1,011 1,230
2,450 2,800 3,150 3,500 3,675 1,517 1,867
3,712 4,275 4,838 5,400 5,682 2,287 2,850
5,251 6,188 7,125 8,063 –– 3,189 4,126
6,375 8,000 9,625 11,250 –– 3,709 5,334
7,315 9,815 12,315 14,815 –– 4,084 6,584
9,625 12,875 16,125 19,375 –– 5,334 8,584
Torque : 8
All information herein is proprietary and condential and may not be copied or reproduced without the expressed written consent of BRAY INTERNATIONAL, Inc.
The technical data herein is for general information only. Product suitability should be based solely upon customer’s detailed knowledge and experience with their application.
Class A
Non-Corrosive,
Lubricating
Service
Valve
Size
mm
25
40
50
65
80
100
125
150
200
250
300
350
400
450
500
Resilient Seated Butterfly Valves – Seating & Unseating Torques
Series 20/21 and 30/31/3A Torques (N-m)
Valve Differential Pressure (Bar)
Full Disc Reduced Disc
0 bar 3.4 bar 7 bar 10.3 bar 12 bar 0 bar 3.4 bar
6 7 7 8 8 6 7
9 10 10 11 11 9 10
12 13 13 14 14 12 13
19 20 21 22 23 19 20
25 27 28 30 31 25 27
39 41 44 46 48 25 28
58 63 69 75 78 37 42
71 80 89 99 103 39 55
134 152 169 188 197 83 101
199 228 257 285 300 136 153
305 351 398 444 467 188 234
431 508 585 663 –– 262 339
524 657 791 924 –– 305 438
595 798 1,002 1,205 –– 336 541
791 1,058 1,325 1,592 –– 379 705
Class B
General Service
Class C
Severe Service
25
40
50
65
80
100
125
150
200
250
300
350
400
450
500
25
40
50
65
80
100
125
150
200
250
300
350
400
450
500
7 7 8 9 9 7 7
10 11 11 12 12 10 11
14 14 15 15 16 14 14
21 22 23 24 25 21 22
28 29 31 33 34 28 29
42 45 48 51 52 28 30
63 69 76 82 85 40 46
79 88 98 108 113 48 61
147 167 186 206 216 91 111
221 253 285 316 332 137 169
336 386 437 488 514 207 258
475 559 644 729 –– 288 373
576 723 870 1,017 –– 335 482
661 887 1,113 1,339 –– 369 595
870 1,164 1,458 1,751 –– 482 776
8 9 10 11 11 8 9
13 13 14 15 15 13 13
17 18 18 19 20 17 18
26 28 29 30 31 26 28
35 37 39 41 42 35 37
53 56 60 64 66 36 39
79 87 95 102 107 50 58
98 111 123 136 142 59 76
184 208 233 258 270 114 139
277 316 356 395 415 171 211
419 483 547 610 642 258 322
593 699 805 911 –– 360 466
720 904 1,087 1,271 –– 419 603
826 1,109 1,391 1,674 –– 461 744
1,087 1,455 1,822 2,189 –– 603 970
Torque : 9
All information herein is proprietary and condential and may not be copied or reproduced without the expressed written consent of BRAY INTERNATIONAL, Inc.
The technical data herein is for general information only. Product suitability should be based solely upon customer’s detailed knowledge and experience with their application.
Resilient Seated Butterfly Valves – Seating & Unseating Torques
Series 32/33, 35/36 Torques (Lb-Ins)
Class B
General Service
(Imperial)
Class C
Valve
Size
inches
24
26
28
30
32
34
36
40
42
44
48
54
60
66
72
78
84
90
96
32, 35 - Max P = 75 psi 33, 36 - Max P = 150 psi
0 psi 25 psi 50 psi 75 psi 0 psi 50 psi 100 psi 150 psi
6,700 8,100 9,500 10,900 10,500 15,000 19,500 24,000
7,900 9,800 11,700 13,600 12,400 18,400 24,400 30,400
9,200 11,600 14,000 16,400 14,200 21,700 29,200 36,700
10,400 13,300 16,200 19,100 16,100 25,100 34,100 43,100
11,700 15,600 19,400 23,300 18,400 29,700 41,100 52,400
13,500 18,500 23,500 28,500 20,950 34,750 48,600 62,400
14,300 20,100 25,900 31,700 23,000 39,000 55,000 71,000
18,200 26,200 34,100 42,000 24,300 46,300 68,300 90,300
20,200 29,200 38,200 47,200 25,000 50,000 75,000 100,000
20,800 32,500 44,200 55,800 26,700 56,700 86,700 118,300
22,000 39,000 56,000 73,000 30,000 70,000 110,000 150,000
41,500 73,500 105,500 138,000 56,300 131,000 173,000 282,000
55,500 98,200 141,000 184,800 75,100 174,500 208,000 376,000
115,700 159,400 203,200 247,000 161,500 277,500 393,400 509,400
Consult Factory
Consult Factory
Consult Factory
Consult Factory
Consult Factory
Series 32/33, 35/36 Torques (N-m)
Class B
General Service
(Metric)
Class C
Valve
Size
mm
600
650
700
750
800
850
900
1,000
1,050
1,100
1,200
1,400
1,500
1,650
1,800
2,000
2,200
2,250
2,400
32, 35, - Max P = 5 bar 33, 36 - Max P = 10.3 bar
0 bar 1.7 bar 3.4 bar 5.2 bar 0 bar 3.4 bar 7 bar 10.3 bar
757 915 1,074 1,232 1,187 1,695 2,204 2,712
893 1,107 1,322 1,537 1,401 2,079 2,757 3,435
1,040 1,311 1,582 1,853 1,605 2,452 3,300 4,147
1,175 1,503 1,831 2,158 1,819 2,836 3,853 4,870
1,322 1,763 2,192 2,633 2,079 3,356 4,644 5,921
1,526 2,091 2,656 3,221 2,367 3,927 5,492 7,051
1,616 2,271 2,927 3,582 2,599 4,407 6,215 8,023
2,057 2,961 3,853 4,746 2,746 5,232 7,718 10,204
2,283 3,300 4,317 5,334 2,825 5,650 8,475 11,300
2,350 3,673 4,995 6,305 3,017 6,407 9,797 13,368
2,486 4,407 6,328 8,249 3,390 7,910 12,430 16,950
4,689 8,304 11,920 15,592 6,361 14,801 19,546 31,862
6,271 11,095 15,931 20,880 8,485 19,716 23,501 42,482
13,072 18,010 22,959 27,907 18,247 31,353 44,448 57,555
Consult Factory
Consult Factory
Consult Factory
Consult Factory
Consult Factory
Torque : 10
All information herein is proprietary and condential and may not be copied or reproduced without the expressed written consent of BRAY INTERNATIONAL, Inc.
The technical data herein is for general information only. Product suitability should be based solely upon customer’s detailed knowledge and experience with their application.
Resilient Seated Butterfly Valves – Seating & Unseating Torques
Seating/Unseating Torques
Bray Series 22/23 Valves
In. mm
2 50
2.5 65
3 80
4 100
5 125
Valve
Size
1) Torques listed are for PTFE and UHMWPE trims.
2) All information based on full rated pressure differential.
6 150
8 200
10 250
12 300
14 350
16 400
18 450
20 500
24 600
∆P = 0-150 psi ∆P = 0-10.3 bar
Lb-In N-m
288 33
350 40
560 63
720 81
960 108
1,300 147
2,402 271
3,840 434
5,812 657
8,000 904
11,000 1,243
15,500 1,751
19,300 2,181
30,500 3,446
Torque : 11
All information herein is proprietary and condential and may not be copied or reproduced without the expressed written consent of BRAY INTERNATIONAL, Inc.
The technical data herein is for general information only. Product suitability should be based solely upon customer’s detailed knowledge and experience with their application.
Dynamic Torque Factors (Imperial)
To Use the Torque Chart, note the following:
Resilient Seated Butterfly Valves – Torques
1. Dynamic Torque values include all bearing friction and
stem-seal friction torques.
2. Dynamic Torque values are per 1 PSI ∆P. To determine
dynamic torque (lb-in) at a desired angle of opening, multiply
the pressure drop ∆P at this angle by the appropriate dynamic
torque factor in the charts below.
Series 20/21 and 30/31/3A (Dynamic Torque Factor - lb-in./psi)
Angle of Opening
2.5 0.216 0.240 0.430 0.865 1.386 2.388 4.085 5.858 5.827 0.000
Valve
Size
inches
10° 20° 30° 40° 50° 60° 70° 75° 80° 90°
2 0.113 0.126 0.225 0.453 0.726 1.251 2.139 3.068 3.052 0.000
3 0.367 0.408 0.732 1.473 2.359 4.065 6.952 9.970 9.918 0.000
4 0.855 0.949 1.702 3.425 5.486 9.454 16.168 23.187 23.065 0.000
5 1.650 1.833 3.287 6.613 10.593 18.253 31.217 44.769 44.533 0.000
6 2.494 2.771 4.969 9.997 16.014 27.594 47.192 67.680 67.323 0.000
8 6.603 6.736 12.077 24.298 38.925 67.073 114.707 164.506 163.64 0.000
10 11.990 13.322 23.885 48.056 76.985 132.653 226.862 325.353 323.640 0.000
12 20.892 23.214 41.619 83.735 134.142 231.141 395.295 566.910 563.925 0.000
14 30.039 33.377 59.841 120.396 192.873 332.342 568.366 815.119 810.828 0.000
16 45.652 50.724 90.942 182.970’ 293.115 505.070 863.764 1,238.762 1,232.240 0.000
18 65.909 73.232 131.295 264.159 423.178 729.184 1,247.040 1,788.435 1,779.020 0.000
20 91.415 101.573 182.105 366.387 586.945 1,011.373 1,729.637 2,480.549 2,467.498 0.000
3. Bray recommends sizing control valves between 20° and
70°, with 60° the preferred angle.
4. Dynamic Torque will tend to close all Bray valves whose
disc are symmetrical to the stem.
Example: 4” Valve; 60° Open with a 10 PSI pressure drop: [Td = (9.454)(10) = 94.54 lb-in]
Series 32/33, 35/36 (Dynamic Torque Factor - lb-in./psi)
Angle of Opening
Valve
Size
inches
Example: 24” Valve; 60° Open with a 10 PSI pressure drop: [Td = (1,751.990)(10) = 17,519.90 lb-in]
Torque : 12
10° 20° 30° 40° 50° 60° 70° 75° 80° 90°
24 158.358 175.953 315.459 634.688 1,016.758 1,751.990 2,996.230 4,297.026 4,274.403 0.000
30 315.318 350.353 628.133 1,263.773 2,024.539 3,488.513 5,966.008 8,556.117 8,511.072 0.000
36 551.884 613.205 1,099.388 2,211.917 3,543.447 6,105.766 10,441.998 14,975.332 14,896.492 0.000
Larger Size Valves - Consult Factory
All information herein is proprietary and condential and may not be copied or reproduced without the expressed written consent of BRAY INTERNATIONAL, Inc.
The technical data herein is for general information only. Product suitability should be based solely upon customer’s detailed knowledge and experience with their application.
Dynamic Torque Factors (Metric)
To Use the Torque Chart, note the following:
Resilient Seated Butterfly Valves – Torques
1. Dynamic Torque values include all bearing friction and
stem-seal friction torques.
2. Dynamic Torque values are per 1 Bar ∆P. To determine
dynamic torque (N-m) at a desired angle of opening, multiply
the pressure drop ∆P at this angle by the appropriate dynamic
torque factor in the charts below.
Series 20/21 and 30/31(Dynamic Torque Factor - N-m/bar)
Angle of Opening
100 0.007 0.007 0.013 0.027 0.043 0.074 0.126 0.181 0.180 0.000
125 0.013 0.014 0.026 0.052 0.083 0.142 0.243 0.349 0.347 0.000
Valve
Size
mm
150 0.019 0.022 0.039 0.078 0.125 0.215 0.368 0.528 0.525 0.000
200 0.052 0.053 0.094 0.190 0.304 0.523 0.895 1.283 1.276 0.000
250 0.094 0.104 0.186 0.375 0.600 1.035 1.770 2.538 2.524 0.000
300 0.163 0.181 0.325 0.653 1.046 1.803 3.083 4.422 4.399 0.000
350 0.234 0.260 0.467 0.939 1.504 2.592 4.433 6.358 6.324 0.000
400 0.356 0.396 0.709 1.427 2.286 3.940 6.737 9.662 9.611 0.000
450 0.514 0.571 1.024 2.060 3.301 5.688 9.727 13.950 13.876 0.000
500 0.713 0.792 1.420 2.858 4.578 7.889 13.491 19.340 19.246 0.000
10° 20° 30° 40° 50° 60° 70° 75° 80° 90°
50 0.001 0.001 0.002 0.004 0.006 0.010 0.017 0.024 0.024 0.000
65 0.002 0.002 0.003 0.007 0.011 0.019 0.032 0.046 0.045 0.000
80 0.003 0.003 0.006 0.011 0.018 0.032 0.054 0.078 0.077 0.000
3. Bray recommends sizing control valves between 20° and
70°, with 60° the preferred angle.
4. Dynamic Torque will tend to close all Bray valves whose
disc are symmetrical to the stem.
Example: 100 mm Valve; 60° Open with a 10 Bar pressure drop: [Td = (.074)(10) = .74 N-m]
Series 32/33, 35/36 (Dynamic Torque Factor - N-m/bar)
Angle of Opening
600 1.235 1.372 2.461 4.951 7.931 13.666 23.371 33.517 33.340 0.000
Valve
Size
mm
750 2.459 2.733 4.899 9.857 15.791 27.210 46.535 66.738 66.386 0.000
900 4.305 4.783 8.575 17.253 27.639 47.625 81.448 116.808 116.193 0.000
Example: 600 mm Valve; 60° Open with a 10 Bar pressure drop: [Td = (13.666)(10) = 136.66 N-m]
Torque : 13
10° 20° 30° 40° 50° 60° 70° 75° 80° 90°
Larger Size Valves - Consult Factory
All information herein is proprietary and condential and may not be copied or reproduced without the expressed written consent of BRAY INTERNATIONAL, Inc.
The technical data herein is for general information only. Product suitability should be based solely upon customer’s detailed knowledge and experience with their application.
Resilient Seated Butterfly Valves – Valve Sizing Coefficients
Valve Sizing Coefficients:
1. Valve Sizing Coefficients (Cv) .............................................. Pages 14-15
1. Cv stands for Valve Sizing Coefcient, sometimes called the Flow Rate Coefcient.
2. Cv varies with the valve size, angle of opening and the manufacturer’s valve style.
3. Cv is dened as the volume of water in USGPM that will ow through a given restriction or valve
opening with a pressure drop of one (1) psi at room temperature.
2. Valve Sizing Coefficients (Kv) .............................................. Pages 16-17
1. Kv stands for Valve Sizing Coefcient, sometimes called the Flow Rate Coefcient.
2. Kv varies with the valve size, angle of opening and the manufacturer’s valve style.
3. Kv is dened as the volume of water in Cubic Meters/Hour (m3/hr) that will ow through a given
restriction or valve opening with a pressure drop of one (1) bar at room temperature.
Coefficients : 14
All information herein is proprietary and condential and may not be copied or reproduced without the expressed written consent of BRAY INTERNATIONAL, Inc.
The technical data herein is for general information only. Product suitability should be based solely upon customer’s detailed knowledge and experience with their application.
Resilient Seated Butterfly Valves – Valve Sizing Coefficients
Series 20/21 - Valve Sizing Coefficient (Cv)
Valve
Size
inches
1 0.1 1 3 6 11 21 36 56 61
1.5 0.2 2 6 11 26 50 87 129 147
2 0.9 7 16 27 45 73 123 172 244
2.5 1 11 25 43 71 115 201 310 439
3 2 16 35 62 102 165 290 488 691
4 4 28 63 110 182 294 515 906 1,282
5 6 44 98 172 284 459 805 1,416 2,070
6 7 59 130 227 376 607 1,065 1,873 2,786
8 13 106 244 427 714 1,147 1,935 3,402 5,191
10 21 168 387 675 1,130 1,815 3,062 5,385 8,238
12 31 245 562 981 1,642 2,636 4,448 7,820 12,102
14 40 307 706 1,234 2,064 3,313 5,590 9,829 15,210
16 52 403 925 1,617 2,706 4,343 7,328 12,885 19,940
18 68 528 1,213 2,121 3,549 5,695 9,610 16,898 26,150
20 85 660 1,517 2,651 4,436 7,120 12,014 21,124 32,690
10º 20º 30º 40º 50º 60º 70º 80º 90º
Disc Position (Degrees)
Series 22/23 - Valve Sizing Coefficient (Cv)
Valve
Size
inches
2 1 7 16 27 44 62 85 115 146
2.5 1 11 24 43 69 110 176 235 300
3 2 15 35 61 98 158 286 413 586
4 3 27 62 109 177 285 503 812 1,051
5 5 43 98 171 276 440 798 1,297 1,814
6 6 57 129 226 364 580 1,048 1,737 2,576
8 12 104 242 424 698 1,111 1,908 3,142 4,354
10 20 165 385 672 1,105 1,761 3,004 4,976 6,834
12 29 241 559 975 1,604 2,591 4,420 7,392 10,090
14 35 300 720 1,280 2,100 3,300 5,700 9,350 12,880
16 45 350 850 1,650 2,750 4,400 7,500 12,320 16,900
18 55 510 1,200 2,100 3,600 5,700 9,830 15,600 21,600
20 80 650 1,550 2,700 4,480 7,100 12,200 19,900 27,500
24 180 1,000 2,450 4,600 7,000 11,300 18,900 28,500 34,800
10º 20º 30º 40º 50º 60º 70º 80º 90º
Disc Position (Degrees)
Coefficients : 15
All information herein is proprietary and condential and may not be copied or reproduced without the expressed written consent of BRAY INTERNATIONAL, Inc.
The technical data herein is for general information only. Product suitability should be based solely upon customer’s detailed knowledge and experience with their application.
Resilient Seated Butterfly Valves – Valve Sizing Coefficients
Series 30/31/31H/3A/3AH/31U - Valve Sizing Coefficient (Cv)
Valve
Size
Inches
2 0.8 7 16 27 43 61 84 114 144
2.5 1 11 24 43 67 107 163 223 282
3 2 15 35 61 96 154 267 364 461
4 3 27 62 109 171 274 496 701 841
5 5 43 98 170 268 428 775 1,146 1,376
6 6 56 129 225 354 567 1,025 1,542 1,850
8 12 102 241 421 680 1,081 1,862 2,842 3,316
10 19 162 382 667 1,076 1,710 2,948 4,525 5,430
12 27 235 555 1,005 1,594 2,563 4,393 6,731 8,077
14 34 299 756 1,320 2,149 3,384 5,939 8,874 10,538
16 45 397 1,001 1,749 2,847 4,483 7,867 11,761 13,966
18 58 507 1,281 2,237 3,643 5,736 10,065 14,496 17,214
20 72 632 1,595 2,786 4,536 7,144 12,535 18,812 22,339
10º 20º 30º 40º 50º 60º 70º 80º 90º
Disc Position (Degrees)
Series 32/33/35/36/35F/36H - Valve Sizing Coefficient (Cv)
Valve
Size
Inches
22 103 916 2,070 3,510 5,640
24 259 1,028 2,387 4,244 6,962
26 289 1,141 2,752 4,890 7,824
28 295 1,324 3,133 5,399 8,636
30 420 1,652 3,986 7,080 11,328
32 550 2,026 4,636 7,983 12,743
34 533 2,304 5,210 8,834 14,194
36 740 2,775 5,936 9,790 15,572
40 757 2,971 6,925 11,862 19,307
42 783 3,502 7,879 12,997 21,010
44 904 4,066 8,698 14,346 22,818
48 1,023 4,651 10,365 17,010 27,242
52
54 1,299 5,904 13,158 21,594 34,583 55,671 89,411 138,334 168,700
60 1,480 6,400 14,500 24,500 39,400 63,200 102,000 154,000 190,000
66 1,650 7,110 16,100 27,300 43,800 70,200 113,000 171,000 211,000
72 1,900 8,220 18,600 31,500 50,700 81,200 131,000 198,000 244,000
78 2,290 9,910 22,400 38,000 61,000 97,800 158,000 238,000 294,000
84 2,290 11,390 25,800 43,700 70,200 112,400 181,000 274,000 338,000
90
96
10º 20º 30º 40º 50º 60º 70º 80º 90º
Disc Position (Degrees)
Consult Factory
Consult Factory
Consult Factory
9,036
11,040
12,496
13,838
18,090
20,410
22,741
25,053
30,636
35,016
36,712
43,853
14,562 22,028 27,168
18,235 27,186 33,154
19,921 29,700 36,220
22,578 34,683 41,619
28,844 43,003 52,443
32,591 48,558 60,658
36,648 55,438 68,374
40,086 59,667 77,089
50,406 73,990 90,175
54,584 83,421 102,989
58,740 87,430 112,960
70,431 108,968 132,888
Coefficients : 16
All information herein is proprietary and condential and may not be copied or reproduced without the expressed written consent of BRAY INTERNATIONAL, Inc.
The technical data herein is for general information only. Product suitability should be based solely upon customer’s detailed knowledge and experience with their application.
Resilient Seated Butterfly Valves – Valve Sizing Coefficients
Series 20/21 - Valve Sizing Coefficient (Kv)
Valve
Size
mm
25 0.087 0.865 2.595 5.190 9.515 18.165 31.140 48.440 52.765
40 0.173 1.730 5.190 9.515 22.490 43.250 75.255 111.585 127.155
50 0.779 6.055 13.840 23.355 38.925 63.145 106.395 148.780 211.060
65 0.865 9.515 21.625 37.195 61.415 99.475 173.865 268.150 379.735
80 1.730 13.840 30.275 53.630 88.230 142.725 250.850 422.120 597.715
100 3.460 24.220 54.495 95.150 157.430 254.310 445.475 783.690 1,108.930
125 5.190 38.060 84.770 148.780 245.660 397.035 696.325 1,224.840 1,790.550
150 6.055 51.035 112.450 196.355 325.240 525.055 921.225 1,620.145 2,409.890
200 11.245 91.690 211.060 369.355 617.610 992.155 1,673.775 2,942.730 4,490.215
250 18.165 145.320 334.755 583.875 977.450 1,569.975 2,648.630 4,658.025 7,125.870
300 26.815 211.925 486.130 848.565 1,420.330 2,280.140 3,847.520 6,764.300 10,468.230
350 34.600 265.555 610.690 1,067.410 1,785.360 2,865.745 4,835.350 8,502.085 13,156.650
400 44.980 348.595 800.125 1,398.705 2,340.690 3,756.695 6,338.720 11,145.525 17,248.100
450 58.820 456.720 1,049.245 1,834.665 3,069.885 4,926.175 8,312.650 14,616.770 22,619.750
500 73.525 570.900 1,312.205 2,293.115 3,837.140 6,158.800 10,392.110 18,272.260 28,276.850
10º 20º 30º 40º 50º 60º 70º 80º 90º
Disc Position (Degrees)
Series 22/23 - Valve Sizing Coefficient (Kv)
Valve
Size
mm
50 0.865 6.055 13.840 23.355 38.060 53.630 73.525 99.475 126.290
65 0.865 9.515 20.760 37.195 59.685 95.150 152.240 203.275 259.500
80 1.730 12.975 30.275 52.765 84.770 136.670 247.390 357.245 506.890
100 2.595 23.355 53.630 94.285 153.105 246.525 435.095 702.380 909.115
125 4.325 37.195 84.770 147.915 238.740 380.600 690.270 1,121.905 1,569.110
150 5.190 49.305 111.585 195.490 314.860 501.700 906.520 1,502.505 2,228.240
200 10.380 89.960 209.330 366.760 603.770 961.015 1,650.420 2,717.830 3,766.210
250 17.300 142.725 333.025 581.280 955.825 1,523.265 2,598.460 4,304.240 5,911.410
300 25.085 208.465 483.535 843.375 1,387.460 2,241.215 3,823.300 6,394.080 8,727.850
350 30.275 259.500 622.800 1,107.200 1,816.500 2,854.500 4,930.500 8,087.750 11,141.200
400 38.925 302.750 735.250 1,427.250 2,378.750 3,806.000 6,487.500 10,656.800 14,618.500
450 47.575 441.150 1,038.000 1,816.500 3,114.000 4,930.500 8,502.950 13,494.000 18,684.000
500 69.200 562.250 1,340.750 2,335.500 3,875.200 6,141.500 10,553.000 17,213.500 23,787.500
600 155.700 865.000 2,119.250 3,979.000 6,055.000 9,774.500 16,348.500 24,652.500 30,102.000
10º 20º 30º 40º 50º 60º 70º 80º 90º
Disc Position (Degrees)
Coefficients : 17
All information herein is proprietary and condential and may not be copied or reproduced without the expressed written consent of BRAY INTERNATIONAL, Inc.
The technical data herein is for general information only. Product suitability should be based solely upon customer’s detailed knowledge and experience with their application.
Resilient Seated Butterfly Valves – Valve Sizing Coefficients
Series 30/31/31H/3A/3AH/31U - Valve Sizing Coefficient (Kv)
Valve
Size
mm
50 0.692 6.055 13.840 23.355 37.195 52.765 72.660 98.610 124.560
65 0.865 9.515 20.760 37.195 57.955 92.555 140.995 192.895 243.930
80 1.730 12.975 30.275 52.765 83.040 133.210 230.955 314.860 398.765
100 2.595 23.355 53.630 94.285 147.915 237.010 429.040 606.365 727.465
125 4.325 37.195 84.770 147.050 231.820 370.220 670.375 991.290 1,190.240
150 5.190 48.440 111.585 194.625 306.210 490.455 886.625 1,333.830 1,600.250
200 10.380 88.230 208.465 364.165 588.200 935.065 1,610.630 2,458.330 2,868.340
250 16.435 140.130 330.430 576.955 930.740 1,479.150 2,550.020 3,914.125 4,696.950
300 23.355 203.275 480.075 869.325 1,378.810 2,216.995 3,799.945 5,822.315 6,986.605
350 29.410 258.635 653.940 1,141.800 1,858.885 2,927.160 5,137.235 7,676.010 9,115.370
400 38.925 343.405 865.865 1,512.885 2,462.655 3,877.795 6,804.955 10,173.265 12,080.590
450 50.170 438.555 1,108.065 1,935.005 3,151.195 4,961.640 8,706.225 12,539.040 14,890.110
500 62.280 546.680 1,379.675 2,409.890 3,923.640 6,179.560 10,842.775 16,272.380 19,323.235
10º 20º 30º 40º 50º 60º 70º 80º 90º
Disc Position (Degrees)
Series 32/33/35/36/35F/36H - Valve Sizing Coefficient (Kv)
Valve
Size
mm
550
600
650
700
750
800
850
900
1,000
1,050
1,100
1,200
1,300
1,400
1,500
1,650
1,800
2,000
2,200
2,250
2,400
10º 20º 30º 40º 50º 60º 70º 80º 90º
89.095 792.340 1,790.550 3,036.150 4,878.600 37,887.000 12,596.130 19,054.220 23,500.320
224.035 889.220 2,064.755 3,671.060 6,022.130 43,855.500 15,773.275 23,515.890 28,678.210
249.985 986.965 2,380.480 4,229.850 6,767.760 52,765.000 17,231.665 25,690.500 31,330.300
255.175 1,145.260 2,710.045 4,670.135 7,470.140 60,723.000 19,529.970 30,000.795 36,000.435
363.300 1,428.980 3,447.890 6,124.200 9,798.720 37,887.000 24,950.060 37,197.595 45,363.195
475.750 1,752.490 4,010.140 6,905.295 11,022.695 43,855.500 28,191.215 42,002.670 52,469.170
461.045 1,992.960 4,506.650 7,641.410 12,277.810 52,765.000 31,700.520 47,953.870 59,143.510
640.100 2,400.375 5,134.640 8,468.350 13,469.780 60,723.000 34,674.390 51,611.955 66,681.985
654.805 2,569.915 5,990.125 10,260.630 16,700.555 37,887.000 43,601.190 64,001.350 78,001.375
677.295 3,029.230 6,815.335 11,242.405 18,173.650 43,855.500 47,215.160 72,159.165 89,085.485
781.960 3,517.090 7,523.770 12,409.290 19,737.570 52,765.000 50,810.100 75,626.950 97,710.400
884.895 4,023.115 8,965.725 14,713.650 23,564.330 60,723.000 60,922.815 94,257.320 114,948.120
1,123.635 5,106.960 11,381.670 18,678.810 29,914.295 48,155.415 77,340.515 119,658.910 145,925.500
1,280.200 5,536.000 12,542.500 21,192.500 34,081.000 54,668.000 88,230.000 133,210.000 164,350.000
1,427.250 6,150.150 13,926.500 23,614.500 37,887.000 60,723.000 97,745.000 147,915.000 182,515.000
1,643.500 7,110.300 16,089.000 27,247.500 43,855.500 70,238.000 113,315.000 171,270.000 211,060.000
1,980.850 8,572.150 19,376.000 32,870.000 52,765.000 84,597.000 136,670.000 205,870.000 254,310.000
1,980.850 9,852.350 22,317.000 37,800.500 60,723.000 97,226.000 156,565.000 237,010.000 292,370.000
Disc Position (Degrees)
Consult Factory
Consult Factory
Consult Factory
Coefficients : 18
All information herein is proprietary and condential and may not be copied or reproduced without the expressed written consent of BRAY INTERNATIONAL, Inc.
The technical data herein is for general information only. Product suitability should be based solely upon customer’s detailed knowledge and experience with their application.
Resilient Seated Butterfly Valves – Flange to Valve Bolting Guide
Examples of Typical Flange to Valve Bolting*
** Lug Style Bolting
Raised
Raised
Face
Face
Flange
Flange
Valve Body
Valve Body
Raised
Face
Flange
Washer
Flange Width
Flange Width
Including Raise Face
Including Raise Face
If Necessary
If Applicable
** Wafer Style Bolting
Flat Face
Flange
Washer
Washer
Flange
Width x2
Including Raise Face
If Applicable
++ +
+ +
Washer
Width
+
x2
Washer
Washer
Width
Width
Valve Face to Face
Width
of Nut
+
x2
**Minimum Bolt
Engagement
Must Be Equal to
Diameter of Bolt
Minimum Bolt
Engagement
Equal to
Bolt Diameter
4 Threads
+
(2 Per Side)
Length
=
=
=
Washer
Bolt
Flat Face
Flange
Washer
Washer
Overall
Length
Please refer to ASME B-16.5 or B-16.47 for Flange and Bolt Dimension Information
* Double flange style bolting not shown.
** Lug threads may be tapped from both sides and therefore tap may not be continuous.
Mounting : 19
Note: Please refer to Appropriate Bray Technical
Drawings for Dimensions and Bolting information
** Note: Please refer to Appropriate
for the highlighted holes.
Bray Dimensional Drawings for
ASME Class 150 = 26” Valves and larger
specific valve drilling information
ASME Class 300 = 14” Valves and larger
on Wafer and Lug Valves 20” and larger.
ASME Class 650 = 10” Valves and larger
All information herein is proprietary and condential and may not be copied or reproduced without the expressed written consent of BRAY INTERNATIONAL, Inc.
The technical data herein is for general information only. Product suitability should be based solely upon customer’s detailed knowledge and experience with their application.
Resilient Seated Butterfly Valves – Flange Bolt Tensioning Data
Flange Bolt Tensioning
Bray Butterfly Valves with Metal Mating Flanges
A question frequently asked at Bray is “What torque do
I apply to the flange bolts to insure the valve is properly
installed?”. Initially this seems to be a simple request
until all of the factors are analyzed. The installation of
a valve requires several components: the valve, mating
flanges, nuts, bolts and studs. Each is supplied by different
manufacturers and each has different characteristics. The
proper torque for one combination may be too much or
too little for a second combination. The following is a list
of information which needs to be known in order to start
calculating the torque requirements.
Valve
• Type
• Size
• Materials of construction (Body)
• Surface finishes / Surface conditions
Flange
• Type
• Size
• Finish / both sides
• Condition of flange / surface contamination
Note: The elastomer valve seat manufactured by Bray
also acts as the flange gasket. No additional gaskets are
required or recommended. Other valve styles which do
not have integral gaskets will need to have this component
supplied. The characteristics of this component will also
need to be considered.
Complete knowledge of all relevant conditions is almost
impossible to obtain. As a result, the computation of the
exact torque requirement is not practical. No reputable
manufacturer can provide accurate information when so
many outside factors are present.
The International Fasteners Institute covers some of the
details required to “compute” a torque value. Even with this
information the use of a torque wrench is only considered
to be 25% accurate. Based on the difficulty and inaccuracy
of using this method, Bray recommends the use of the
“Turn of the nut” method.
“Turn of the Nut” Tightening
(For ANSI Standard Iron and Steel Flanges)
**For Non-Metallic or non-standard flanges, follow the manufacturers installation
procedures.
Bolt (or Stud)
• Type
• Materials of Construction
• Surface Conditions
Nut
• Type
• Materials of Construction
• Surface Conditions
Lubrication
• Type
• Coverage
General Factors
• Temperature and relative humidity at the time of
installation
• Speed at which bolts are turned
1. The valve and flange faces must be aligned parallel to
each other.
Note: For rubber seated butterfly valves manufactured
by Bray, it is required that the valve be fully opened
prior to the tightening of the flange bolts.
2. After aligning the holes in a joint, sufficient bolts shall
be placed and brought to a ‘snug-tight’ condition to
ensure that the parts of the joint are brought into full
contact with each other. ‘Snug-Tight’ is the tightness
attained by the full effort of a man using a spud wrench.
3. Following the initial snugging operation, bolts shall
be placed in any remaining holes and brought to snugtightness. Re-snugging may be necessary in large
joints.
4. Tighten opposite bolts in sequence to insure even
pressure around the entire flange.
Mounting : 20
All information herein is proprietary and condential and may not be copied or reproduced without the expressed written consent of BRAY INTERNATIONAL, Inc.
The technical data herein is for general information only. Product suitability should be based solely upon customer’s detailed knowledge and experience with their application.
Resilient Seated Butterfly Valves – Flange Bolt Tensioning Data
5. When all bolts are snug-tight, each bolt in the joint then
shall be tightened additionally by the applicable amount
of nut rotation given in Note 1. During tightening there
shall be no rotation of the valve or flange.
Note 1
For bolt lengths not exceeding 8 diameters
or 8 inches (203.2 mm) = 1/4 turn
For bolt lengths exceeding 8 diameters
or 8 inches (203.2 mm) = 1/2 turn
Series 20/21 and 30/31 - Flange Bolt Torque Chart
Valve Size Normal Torque Range Normal Torque Range
In mm Ft-lbs N-m
2 50 30 40
2.5 65 30 40
3 80 35 50
4 100 35 - 40 50 - 55
5 125 35 - 45 50 - 60
6 150 35 - 50 50 - 65
8 200 45 - 55 60 - 75
10 250 55 - 75 75 - 100
12 300 65 - 110 90 - 150
14 350 75 - 120 100 - 165
16 400 75 - 120 100 - 165
18 450 85 - 130 115 - 175
20 500 85 - 130 115 - 175
Disclaimer:
Bray Controls is issuing these recommendations only
as a guide to installation. This recommendation is
based on the full compliance of all materials supplied
to their appropriate specifications. Since many of the
components are not manufactured by Bray we can
take no responsibility for any damage caused during
installation.
Please note that the N-m and Ft-lbs values are based
on bolt size in respective metric and ANSI flanges, i.e.
these values are not a direct conversion between N-m
and Ft-lbs.
The values represent average torques needed to ensure
full compression of the resilient valves’ seats into the
valves’ bodies when installed in pipeline flanges. The
face of both flanges must come into full contact with
the valves’ metal bodies.
No additional torque is required for proper functioning
of the Bray resilient seated valves.
Mounting : 21
All information herein is proprietary and condential and may not be copied or reproduced without the expressed written consent of BRAY INTERNATIONAL, Inc.
The technical data herein is for general information only. Product suitability should be based solely upon customer’s detailed knowledge and experience with their application.
The torque values are based on using new, coarsethreaded, lubricated fasteners. Up to 25% may be
added to the Normal Torque Range values when using
non-lubricated fasteners.
Torque Values specified by flange manufacturers must
not be exceeded.
Resilient Seated Butterfly Valves – Flange Bolt Tensioning Data
Series 22/23 Installation - Flange Bolt Torque Chart, 150 lb Flanges
Valve Size Normal Torque Range Max Torque Range
In mm Ft-lbs N-m Ft-lbs N-m
2 50 30 40 35 50
2.5 65 30 40 35 50
3 80 35 50 40 55
4 100 35 - 40 50 - 55 40 55
5 125 35 - 45 50 - 60 50 65
6 150 35 - 50 50 - 65 65 90
8 200 45 - 55 60 - 75 80 110
10 250 55 - 75 75 - 100 100 135
12 300 65 - 110 90 - 150 120 165
14 350 75 - 120 100 - 165 140 190
16 400 75 - 120 100 - 165 140 190
18 450 85 - 130 115 - 175 170 230
20 500 85 - 130 115 - 175 180 245
24 600 100 - 150 135 - 205 220 300
The torque values are based on using new, coarsethreaded, lubricated fasteners. Up to 15% may be
added to the Normal Torque Range values when using
non-lubricated fasteners. However, the maximum
torque should not be exceeded.
Flange gaskets are normally not used for installation
of S22/23 valves. Flange leakage may be caused by
combination of out-of-parallel and/or misaligned
flanges, and surface damage on the flange face and/or
the face of the valve seat. In such cases, suitable flange
gaskets may be used to control flange leakage.
Torque values specified by manufacturers of certain
flanges, for example plastic flanges, could be lower than
the values specified above. In such cases, the flange
manufacturers’ torque values must not be exceeded.
Use flange gaskets if necessary to secure flange seal.
Mounting : 22
All information herein is proprietary and condential and may not be copied or reproduced without the expressed written consent of BRAY INTERNATIONAL, Inc.
The technical data herein is for general information only. Product suitability should be based solely upon customer’s detailed knowledge and experience with their application.
Resilient Seated Butterfly Valves – Standard Metal Specifications
Part Material ASTM No. UNS No.
Body
Disc/Stem
1-12”(25-300mm) One Piece
Disc/Stem
14-20”
(350-500mm)
Fabricated
Disc
Stem
Series 20/21 - Standard Metal Specifications
Cast Iron A126 Class B
Ductile Iron A395 Gr. 60-40-18 F32800
316 Stainless Steel A351 CF8M J92900
Aluminum B26 Class B
316 Stainless Steel A351 CF8M J92900
®
Hastelloy
17-4 ph Stainless Steel A747 CB7Cu1 Heat Treated J92180
316 Stainless Steel A240 S31600
Hastelloy
17-4 ph Stainless Steel A564 630 Heat Treated S17400
316 Stainless Steel A276 S31600
Hastelloy
17-4 ph Stainless Steel A564 630 Heat Treated S17400
C22 * B494 CX2MW N26022
®
C276 * B575 N10276
®
C276 * B575 N10276
* Hastelloy
Series 22/23 - Standard Metal Specifications
Part Material ASTM No. UNS No.
Ductile Iron A395 Gr. 60-40-18 F32800
Body
Disc
Stem
®
is a registered trademark of Haynes International, Inc.
316 Stainless Steel A351 CF8M J92900
Carbon Steel A216 WCB J030002
316 Stainless Steel A351 CF8M J92900
PTFE/316 SS (2”-12”) A351 CF8M J92900
PTFE/17-4 ph SS (14”-24”) A547 CB7Cu1 J92180
UHMWPE/316 SS (2”-6”) A351 CF8M J92900
UHMWPE/DI (8”-12”) A536 Gr 65-45-12 F33100
Hastelloy
Titanium
17-4 ph Stainless Steel A564 630 Heat Treated S17400
®
C22 * B494 CX2MW N26022
Metal Specs : 23
All information herein is proprietary and condential and may not be copied or reproduced without the expressed written consent of BRAY INTERNATIONAL, Inc.
The technical data herein is for general information only. Product suitability should be based solely upon customer’s detailed knowledge and experience with their application.
Resilient Seated Butterfly Valves – Standard Metal Specifications
Series 30/31, 31H, 3A/3AH, 31U - Standard Metal Specifications
Part Material ASTM No.
Cast Iron A126 Class B
Ductile Iron A536 Gr. 65-45-12 F33100
Body
Disc
Stem
* Hastelloy® is a registered trademark of Haynes International, Inc.
Monel® is a registered trademark of International Nickel Company, Inc.
254 SMO™ is a registered trademark of Avesta AB.
AL-6XN® is a registered trademark of ATI Properties, Inc.
Ductile Iron A395 F32800
Carbon Steel A216 WCB J030002
Nickel Aluminum Bronze B148 C95800
Aluminum B26 Class B
Aluminum Bronze B148 C95400
Nickel Aluminum Bronze B148 C95800
Nylon Coated Ductile Iron A536 Gr. 65-45-12 F33100
316 Stainless Steel A351 CF8M J92900
304 Stainless Steel A351 CF8 J92600
Duplex Stainless Steel A995 Gr 4A J92205
Super Duplex Stainless Steel A995 Gr 5A J93404
Super Austenitic Stainless Steel
(254 SMO™)*
Hastelloy® C-276 * B575 N10276
304 Stainless Steel A276 S30400
316 Stainless Steel A276 S31600
416 Stainless Steel A582 S41600
17-4 ph Stainless Steel A564 630 Heat Treated S17400
®
Monel
* B865 N05500
A351 Grade CK3MCuN S31254
UNS
No.
30/31 31H 3A/3AH 31U
• • •
• • •
•
• • •
•
•
• • •
•
• • •
• • • •
• •
• •
• •
• •
• •
• •
• •
• • • •
•
• • •
Metal Specs : 24
All information herein is proprietary and condential and may not be copied or reproduced without the expressed written consent of BRAY INTERNATIONAL, Inc.
The technical data herein is for general information only. Product suitability should be based solely upon customer’s detailed knowledge and experience with their application.
Resilient Seated Butterfly Valves – Standard Metal Specifications
Series 32/33, 35/36, 35F, 36H - Standard Metal Specifications
Part Material ASTM No.
Cast Iron A126 Class B
Body
Disc
Stem
* Hastelloy® is a registered trademark of Haynes International, Inc.
Monel® is a registered trademark of International Nickel Company, Inc.
254 SMO™ is a registered trademark of Avesta AB.
AL-6XN® is a registered trademark of ATI Properties, Inc.
Ductile Iron A536 Gr. 65-45-12 F33100
Carbon Steel A216 Gr. WCB J030002
316 Stainless Steel A351 CF8M J92900
Nickel Aluminum Bronze B148 C95800
Nylon Coated Ductile Iron A536 Gr. 65-45-12 F33100
316 Stainless Steel A351 CF8M J92900
304 Stainless Steel A351 CF8 J92600
Hastelloy® C-276 * B575 N10276
Hastelloy® C-22 * B494 CX2MW N26022
Duplex Stainless Steel A995 Gr 5A J93404
Super Austenitic Stainless Steel
(254 SMO ™) *
®
Monel
* A494 Grade M-35-1 N24135
304 Stainless Steel A276 S30400
316 Stainless Steel A276 S31600
416 Stainless Steel A582 S41600
17-4 ph Stainless Steel A564 630 Heat Treated S17400
Austenitic Stainless Steel A479 S31651
Super Austenitic Stainless Steel (AL-6XN®) * A276 N08367
®
Monel
* B865 N05500
A351 Grade CK3MCuN S31254
UNS
No.
32-36 36H 35F
• •
• • •
•
•
• •
• •
•
•
CF
CF
•
• • •
• • •
•
• •
• •
•
• •
•
• •
•
Metal Specs : 25
All information herein is proprietary and condential and may not be copied or reproduced without the expressed written consent of BRAY INTERNATIONAL, Inc.
The technical data herein is for general information only. Product suitability should be based solely upon customer’s detailed knowledge and experience with their application.
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