Rupture Disk
The original rupture disk (bursting disc) manufacturer shaping the growth of pressure relief devices for over 80 years.

Assemblies
Custom Rupture Disk (Bursting Disc)

Many customer applications cannot be met using standard rupture disk (bursting disc) and safety head designs. That’s why BS&B has invested in a department committed to the development of customized rupture disk assemblies.

Examples of special requests:

  • Special disk holder design
  • Exotic materials
  • Cryogenic or elevated temperature
  • Lower or higher item standard burst pressures
  • Hermetic sealing
  • Qualification procedures, testing and documentation

BS&B will design the most cost effective solution for your application. We use state-of-the-art production methods including precision machining, CAD/CAM, electron beam or laser welding. BS&B has designed and manufactured customized rupture disk (bursting disc) assemblies to meet customer requirements in a wide range of industries including aviation, cryogenic or high temperature systems, fire suppression, plastic extrusion, aerospace and defense.

STA-KUL Sealed Type Safety Heads

BS&B STA-KUL Sealed Type Safety Heads are bottle-tight pressure relief devices designed primarily for air conditioning systems. When disk ruptures, complete unit is replaced.

The STA-KUL unit has two important features:

1. Controlled pressure accuracy
2. No leakage

Each unit is leak-tested before it leaves the factory.

The bottle-tight capability of the STA-KUL unit makes it highly desirable for other applications. It is readily adaptable for use on gas cylinders, pressure gauges, hydraulic accumulators, and portable compressed air systems.

BS&B STA-KUL units are available in two standard types:

Type 22

Brass body with Type B of BV solid metal rupture disk.

Rupture disk will withstand 14.7 psi back pressure without vacuum support at any pressure rating specified within minimum/maximum range. If disk will be exposed to back pressure higher than 14.7 psi at specified operating temperature, consult factory. A vacuum support may be required.

1. For optimum service life normal operating pressure should be at or below:

Disk Material Operating Pressure
Nickel 70% specified disk  rating
Silver 50% specified disk rating

2. Temperature at or below 750F for nickel disk, 250 F for silver disk.
3. Static pressure load on disk (non-pulsating).

Type 42

Brass body with Type D or DV composite rupture disk (bursting disc) with a metal top section and silver or fluoropolymer seal.

Vacuum support required if disk has specified pressure rating below 550 psi @ 72° F. or will be exposed to elevated temperature and 14.7 psi back pressure.

Application guidelines

1. Pressure, temperature or service conditions that exceed limits for Type 22 unit
2. Normal operating pressure should not exceed 80% of disk rating.

Note: If the atmospheric condition limit selection of top section metal, specify acceptable material(s).

Standard STA-KUL Sealed Type Safety Heads

Disk Material Operating Pressure
Nickel 70% specified disk
Silver 50% specified disk

Standard STA-KUL Seal Type safety Heads

* Lower minimum pressure ratings available on request.

MANUFACTURING RANGES FOR SOLID METAL OR COMPOSITE DISKS

Rupture Disks

Type No. Material Material Rupture Pressure PSIG Kg/cm2 at 22o C Max. Temp. 
o F 
o C
      Min. Max.  
22 
B or BV
Brass Nickel 200 
14.1
1000 
70.3
750 
399
    Silver 130 
9.1
1000 
70.3
250 
121
42 
D or DV
Brass 316SS or Inconel with fluoropolymer seal 115 
8.1
700 
49.2
500 
260
    Nickel with fluoropolymer seal 77 
5.4
700 
49.2
500 
260
    316SS or Inconel with silver seal 180 
12.7
1000 
70.3
800 
427
Desired Pressure rating Test specimens must rupture within limits below of the pressure you specify Desired Pressure Rating Test specimens must rupture within limits below of the pressure you specify
PSIG Plus  Minus Kg/CM2 Plus  Minus
2.5 -3.5 1    psig 1    psig .176-.246 .070  Kg/CM2 .070Kg/CM2
4 - 6 2    psig 1    psig .281-.422 .141  Kg/CM2 .070Kg/CM2
7 - 10 2.5 psig 1.5 psig .49-.70 .176  Kg/CM2 .105 Kg/CM2
11- 16 3    psig 2    psig .77-1.13 .211  Kg/CM2 .141 Kg/CM2
17 - 25 4    psig 2    psig 1.20-1.76 .281  Kg/CM2 .141 Kg/CM2
26 - 40 5    psig 3    psig 1.83-2.81 .352  Kg/CM2 .211 Kg/CM2
41 - 65 6    psig 4    psig 2.88-4.57 .422  Kg/CM2 .281 Kg/CM2
66 -100 9    psig 5    psig 4.64-7.03 .633  Kg/CM2 .352 Kg/CM2
101-150 12  psig 6    psig 7.10-10.55 .844  Kg/CM2 .422 Kg/CM2
151-200 16  psig 9    psig 10.62-14.06 1.125 Kg/CM2 .633 Kg/CM2
201-350 23  psig 12  psig 14.14-24.61 1.617Kg/CM2 .844 Kg/CM2
351-500 30  psig 15  psig 24.68-35.16 2.11 Kg/CM2 1.055Kg/CM2
501-&up 6    pct. 3    pct. 35.23- &up 6 pct.  3 pct.

Dimensions for STA-KUL Sealed Type Safety Heads

Assembly Number Connections Discharge Area Overall height Hex across flat
Inlet Outlet
AC 1 1/4"  MPT FREE  .049 1 3/32 1 1/8
AC 2 1/2"  MPT FREE .196 1 1/4 1 1/8
A 3 3/8"  MPT 3/8"  SAE .062 1 7/8 1 1/8
A 4 3/8"  MPT 1/2"  SAE .110 1 15/16 1 1/8
A 5 3/8"  MPT 1/2"  MPT .110 1 7/8 1 1/8
A 6 1/2"  MPT 1/2"  MPT .196 2 1/16 1 1/8
A 7 1/4"  MPT Muffled .049 1 9/16 1 1/8
A 8 1/2"  MPT Muffled .196 1 3/4 1 1/8
A 9 3/4"  MPT Muffled .307 2 11/64 1 1/8

Screw Type Safety Heads

BS&B Screw Type Safety Heads are widely used on autoclaves, laboratory pressure equipment, aerospace ground support equipment, bottled gases, cryogenic systems and compressed air or liquid systems. The standard BS&B Screw Type Safety Head utilizes a single body with 15,000# maximum rating that is designed to accept four different holddown rings. Three rings have a flat seat design, the fourth an angular seat.

One flat seat ring has a 11/16 " burst diameter and will accept low pressure Types B, D and DV disks up to 1000 psi maximum pressure. The angular seat ring has a 1/2 " burst diameter and is used for Type B disks only up to 3000 psi maximum pressure. The second flat seat ring also has 1/2 " diameter and uses Type B disks from 3000 to 10000 psi maximum. The fourth ring has a 7/16 " flat seat and is used for disks from 7500 to 15,000 psi.

Standard rupture disks (bursting discs) for BS&B Screw Type Safety Heads are listed on the following pages. In addition to the four sizes described above, 3/16" flat seat rupture disks (bursting discs) and 1/4 " angular seat rupture disks (bursting discs) are also available in standard disk metals and bursting pressures. These are designed to fit autoclave equipment. The 7/16" and 1/2 " flat seat rupture disks (bursting discs) will also fit autoclave equipment.

Standard material for inlet connection, holddown ring and outlet connection: 303 stainless steel. Other materials available upon request.

Screw Type Safety Heads with rupture disk (bursting disc) bursting pressures from 15,000 to 100,000 psi are available in a special design. Consult factory.

Pressure/Temperature Ratings for Screw Type Safety Head Fittings

Service Temp. 

C
Maximum Rating 
PSIG 
kg/cm2
-20 to +100 
-29 to +38
15,000 
1,055
200 
93
14,625 
1,028
300 
149
14,175 
997
400 
204
13,875 
976
500 
260
13,050 
918
600 
316
11,550 
812
700 
371
10,275 
722
800 
427
9,300 
654
900 
482
8,400 
590
1000 
538
7,925 
557

Dimensions for Screw Type Safety Heads

MIN-3000 
PSI
MIN-1000 
PSI
3000-10000 
PSI
7500-1500 
PSI
CONNECTIONS Inlet 
Bore Size 
(Dia.)* 
in. 
mm
overall 
height 
in. mm.
hex across flats
1/2(A) 
12.7
11/16(F) 
17.4
1/2(F) 
12.7
7/16(F) 
11.1
Inlet  
in  
mm.
outlet     Inlet  
in. mm.
Outlet  
in. mm.
SA-7 SF-47 SF-57 SF-67 1/4MPT 
6.4
Free 1/4 
6.4
2 1/16 
52.4
1 1/4 
31.8
1 1/8 
28.6
SA-8 SF-48 SF-58 SF-68 1/2MPT 
12.7
Free 13/32 
10.3
2 3/16 
55.6
1 1/4 
31.8
1 1/8 
28.6
SA-9 SF-49 SF-59 SF-69 1/4MPT 
6.4
1/2MPT 
12.7
1/4 
6.4
2 7/8 
73.0
1 1/4 
31.8
1 1/8 
28.6
SA-10 SF-50 SF-60 SF-70 1/2MPT 
12.7
1/2MPT 
12.7
13/32 
10.3

76.2
1 1/4 
31.8
1 1/8 
28.6
SA-11 SF-51 SF-61 SF-71 1/4MPT 
6.4
Muffled 1/4 
6.4
2 3/8 
60.3
1 1/4 
31.8
1 1/8 
28.6
SA-12 SF-52 SF-62 SF-72 1/2MPT 
12.7
Muffled 13/32 
10.3
2 1/2 
63.5
1 1/4 
31.8
1 1/8 
28.6

* 1/2" inlet bore available on All Assemblies with 1/2" MPT inlet when disk rating is below 7500 psi @ 72F.

Rupture Disks for Screw Type Safety Heads

The following BS&B rupture disks (bursting discs) for screw type Safety Heads are standard. Those in the most popular materials and bursting pressures are "shelf items" and available for immediate delivery. Consult your local representative for current listing of these disks. Disks with higher or lower bursting pressures than those listed and in other materials are available on special order.

Minimum/maximum pressure ratings and maximum temperature ratings have two sets of figures. Pressure ratings shown in black are psig @ 72F., those in red are kg/cm2 @ 22° C. Temperature PSIG shown in black are °F., those in red are °C.

Before specifying any disk, see table of manufacturing ranges and notes at bottom of page.

1/2" ANGULAR SEAT SOLID METAL DISKS - 3000 PSI MAX: TYPES B AND BV

Disk Material Unlined Disks FEP Lined Disks
Min. pres. Max. pres. Max. temp. Min. pres.
1/sides
Min. pres. 
2/sides
Max. pres. 
1/2sides
Max. temp. 
FEP
Aluminum 80 
5.63
1500 
105.5
250 
121
235 
16.5
380 
26.7
1500 
105.5
250 
121
Silver 175 
12.3
3000 
211.0
250 
121
395 
27.8
490 
34.5
200 
140.7
250 
121
Nickel 280 
19.7
3000 
211.0
750 
399
500 
35.2
600 
42.2
3000 
211.0
400 
204
Monel 340 
24.0
3000 
211.0
800 
427
500 
35.2
600 
42.2
3000 
211.0
400 
204
Inconel 440 
31.0
3000 
211.0
900 
482
700 
49.2
790 
55.6
3000 
211.0
400 
204
316 S.S. 625 
44.0
3000 
211.0
900 
482
820 
57.7
910 
64.0
3000 
211.0
400 
204

11/16" FLAT SEAT SOLID METAL DISKS
1000 PSI MAX: Types B and BV

Disk Material Unilined Disks  FEP Lined Disks
Min. pres Max. pres. Max. Temp. Min. Pres. 
1 Side 
FEP
Max. pres. 
1 Side
Max. temp. 
FEP
Aluminum 55 
3.87
650 
45.7
250 
121
225 
15.8
650 
45.7
250 
121
Silver 130 
9.1
1000 
70.3
250 
121
300 
21.1
1000 
70.3
250 
121
Nickel 200 
14.1
1000 
70.3
750 
399
370 
26.0
1000 
70.3
400 
204
Monel 250 
17.6
1000 
70.3
800 
427
420 
29.5
1000 
70.3
400 
204
Inconel 325 
22.8
1000 
70.3
900 
482
500 
35.2
1000 
70.3
400 
204
316 S.S 455 
32.0
1000 
70.3
900 
482
650 
45.7
1000 
70.3
400 
204

  11/16" FLAT SEAT COMPOSITE DISKS
1000 PSI MAX: Types D and DV

Top Section Material
Seal Material Minimum Pressure Max. pres. All 
Matls
Max. Temp
Inconel 
316S.S.
Nickel Alum.
TFE .003" 
thick
___ ___ 40 
2.81
___ 250 
121
TFE(Fluoropolymer
/Halon)
115 
8.1
77 
5.41
___ 700 
49.2
500 
260
FEP(Fluoropolymer) 115 
8.1
___ ___ 700 
49.2
400 
204
Aluminum 150 
10.5
___ ___ 800 
56.3
800 
427
Silver 180 
12.7
___ ___ 1000 
70.3
800 
427
Nickel 300 
21.1
___ ___ 1000 
70.3
1000 
538
Monel 400 
28.1
___ ___ 1000 
70.3
1000 
538
Inconel 600 
42.2
___ ___ 1000 
70.3
1000 
538
316 S.S. 700 
49.2
___ ___ 1000 
70.3
1000 
538

Manufacturing Ranges for Solid Metal of Composite Disks

Desired pressure Rating Test specimens must rupture within limits below of the pressure you 
specify
Desired Pressure  
Rating
Test Specimens must rupture within limits below of the pressure you specify
PSIG Plus Minus Kg/CM2 Plus Minus
26 - 40 5      psig 3    psig 1.83  -  2.81 .352   Kg/CM2 .211   Kg/CM2
41  - 65 6      psig 4    psig 2.88  -  4.57 .422   Kg/CM2 .281   Kg/CM2
66 - 100 9      psig 5    psig  4.64  -  7.03 .633   Kg/CM2 .352   Kg/CM2
101 - 150 12    psig 6    psig 7.10  -  10.55 .844   Kg/CM2 .422   Kg/CM2
151 - 200 16    psig 9    psig 10.62-   14.06 1.125 Kg/CM2 .633   Kg/CM2
201 - 350 23    psig 12  psig 14.14-   24.61 1.617 Kg/CM2 .844   Kg/CM2
351 - 500 30    psig 15  psig 24.68-   35.16 2.11   Kg/CM2 1.055 Kg/CM2
501   & up 6      pct. 3    pct. 35.23   &Up 6 pct. 3 pct.

NOTES:

1. If 1/2 ", angular seat Type B disk will be exposed to vacuum or back pressure, check Type B catalog for minimum burst pressures that will withstand full vacuum. If vacuum support is required, specify Type BV. If Type D disk will be exposed to vacuum, specify Type DV.
2. If flat seat Type B disk will be exposed to vacuum or back pressure, vacuum support is not required if disk rating exceeds the following:

aluminum 200 psi Monel 500 psi
silver 200 psi lnconel 750 psi
nickel 375 psi 316 stainless steel 750 psi

If vacuum support is required, specify Type BV.
3. Vacuum supports for 1/2" angular seat and 11/16" flat seat Type BV disks are not attached. Standard material for vacuum support is 316 stainless steel. Materials available on special order include Inconel, Nickel, Monel, Hastelloy B and C, titanium and tantalum.
4. Linings on Type B disks have very little creep resistance. Operating margin for lined disks must be greater than for unlined disks.
5. Linings are sheet form bonded to disk metal. All liners have passed spark test to assure pinhole-free condition.

Rupture Disks for Screw Type Safety Heads

The following BS&B rupture disks (bursting discs) for autoclave equipment are standard. Those in the most popular materials and bursting pressures are "shelf items" and available for immediate delivery. Consult your local representative for current listing of these disks. Disks with higher and lower bursting pressures than those listed and in other materials are available on special order.
Minimum/maximum pressure ratings and maximum temperature ratings have two sets of figures. Pressure ratings shown in black are psig @ 72° F., those in red are kg/cm2 @ 22° C. Temperatures shown in black are °F., those in red are °C.
Before specifying any disk, see table of manufacturing ranges and notes.

MANUFACTURING RANGES FOR SOLID METAL DISKS

Desired Pressure Rating Test specimens must rupture within limits below of the pressure you specify
PSIG Plus Minus
66   -100  9   psig 5   psig
101 -150 12 psig 6   psig
151 -200 16 psig 9   psig
201 -350 23 psig 12 psig
351 -500 30 psig 15 psig
501 & Up 6 pct. 3 pct.
Desired Pressure Rating Test specimens must rupture within limits below of the pressure you specify
Kg/CM2 Plus Minus
4.64   -7.03 .633   Kg/CM2 .352   Kg/CM2
7.10   -10.55 .844   Kg/CM2 .422   Kg/CM2
10.62 -14.06 1.125 Kg/CM2 .633   Kg/CM2
14.14 -24.61 1.617 Kg/CM2 .844   Kg/CM2
24.68 -35.16 2.11   Kg/CM2 1.055 Kg/CM2
35.23 & Up 6 pct. 3 pct.

3 /16" FLAT SEAT SOLID METAL DISKS-20,000 PSI MAX: Type B

Disk Material Unlined Disks FEP Lined Disks
Min. Pres. Max. Pres. Max. Temp. Min. Pres.   1 side Min. Pres. 
2 sides
Max. Pres. FEP 1/2 sides Max. Temp. FEP
Aluminum 220 
15.5
1750 
123.0
250 
121
940 
66.1
1190 
83.7
1750 
123.0
250 
121
Silver 500 
35.2
4500 
316.2
250 
121
1200 
84.4
1450 
102.0
3000 
211.0
250 
121
Nickel 770 
54.1
20000 
1407
750 
399
1480 
104.0
1730 
121.7
10000 
703
400 
204
Monel 960 
67.5
20000 
1407
800 
427
1760 
123.8
2000 
140.7
12000 
844
400 
204
Inconel 1250 
88.0
20000 
1407
900 
482
2250 
158.2
2500 
175.8
13200 
929
400 
204
316 S.S. 1750 
123.0
20000 
1407
900 
482
3000 
211.0
3250 
228.4
13200 
929
400 
204

1/4 " ANGULAR SEAT SOLID METAL DISKS-50,000 PSI MAX : Type B

Disk Material Unlined Disks FEP Lined Disks
Min. Pres. Max. Pres. Max.    Temp. Min. Pres. 1 Side Min. Pres. 2 Sides Max. Pres. FEP 1/2 Sides Max. Temp. FEP
Aluminum 160 
11.2
2000 
140.7
250 
121
470 
33.0
675 
47.5
2000 
140.7
250 
121
Silver 360 
25.3
6000 
422
250 
121
790 
55.5
1000 
70.3
2500 
175.7
250 
121
Nickel 550 
38.6
35000 
2460
750 
399
1000 
70.3
1200 
84.4
10000 
703
400 
204
Monel 690 
48.5
40000 
2813
800 
427
1190 
83.7
1390 
97.8
10000 
703
400 
204
Inconel 900 
63.3
45000 
3164
900 
482
1500 
105.5
1700 
119.5
15000 
1055
400 
204
316 S.S. 1250 
88.0
50000 
3516
900 
482
1950 
137.1
2150 
151.2
15000 
1055
400 
204

1/2" FLAT HEAD SOLID METAL DISKS -10,000 PSI MAX : TYPE B

Disk Material Unlined Disks FEP Lined Disks
Min. Pres. Max. Pres. Max. Temp. Min. Pres. 
1 Side
Min. Pres. 
2 Sides
Max. Temp. 
FEP 
1 Side
Max. Temp. FEP
Aluminum 90 
6.33
1000 
70.3
250 
121
275 
19.3
380 
26.7
1000 
70.3
250 
121
Silver 190 
13.4
1700 
119.5
250 
121
400 
28.1
510 
35.8
1700 
119.5
250 
121
Nickel 300 
21.1
7500 
527
750 
399
500 
35.2
610 
42.8
3750 
263.8
400 
204
Monel 375 
26.4
7500 
527
800 
427
575 
40.4
685 
48.1
4500 
316.2
400 
204
Inconel 500 
35.2
10000 
703
900 
482
725 
51.0
835 
58.7
5000 
352
400 
204
316 S.S. 700 
49.2
10000 
703
900 
482
950 
66.8
1060 
74.6
5000 
352
400 
204

 7/16" FLAT SEAT SOLID METAL DISKS 20,000 PSI MAX : Type B

Disk Material Unlined Disks
Min. Pres. Max. Pres. Max. Temp.
Nickel 7,500 
527
15,000 
1,055
750 
399
Monel 7,500 
527
18,000 
1,266
800 
427
Inconel 10,000 
703
20,000 
1,407
900 
482
316 S.S. 10,000 
703
20,000 
1,407
900 
482

Notes:

1. Vacuum supports are not available for 3/16", 1/4", 7/18" or 1/2" flat seat Type B disks. All disks in these groups with ratings greater than 1 1/2 times the unlined minimums will stand full vacuum without a vacuum support.
2. Linings on Type B Disks have very little creep resistance. Operating margin for lined disks must be greater than for unlined disks.
3. Liners are sheet form bond to disk metal. All liners have passed spark test to assure pinhole-free condition.