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	¼"  MPT	FREE	.049	1 3/32	1 1/8
AC 2	1/2"  MPT	FREE	.196	1 ¼	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	¼"  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 ¼ " 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	¼MPT  6.4	Free	¼  6.4	2 1/16  52.4	1 ¼  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 ¼  31.8	1 1/8  28.6
SA-9	SF-49	SF-59	SF-69	¼MPT  6.4	1/2MPT  12.7	¼  6.4	2 7/8  73.0	1 ¼  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 ¼  31.8	1 1/8  28.6
SA-11	SF-51	SF-61	SF-71	¼MPT  6.4	Muffled	¼  6.4	2 3/8  60.3	1 ¼  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 ¼  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

¼ " 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", ¼", 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.