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:
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. F 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 |
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.