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

BIO-SAF SystemTM


BS&B's comprehensive range of sanitary rupture disks (bursting discs), holders, and fittings has been specially designed with a uniformly smooth internal finish in non-contaminating materials for overpressure protection in sanitary/aseptic applications. The Bio-Saf range meets the demanding sanitary criteria necessary in today's pharmaceutical, biotechnology and food processing industries. 

All BS&B sanitary disk holders and fittings are designed with a standard sanitary clamp configuration to permit easy and fast disk installation. The holders may be connected to other sanitary tubing or fittings using standard clamps and sanitary gaskets. Holders and fittings are also available with butt, tank weld end connections or a flush mounted option. 

Surface Finish

Our standard surface finish on rupture disk (bursting disc) holders and fittings is 20~25Ra on all wetted parts. Polishing or electropolishing is used to meet customer special requirements.

Reverse Buckling and Composite Disk Nomenclature

Reverse buckling and composite disks are offered in type -S or type -ST (e.g. RLS-S, RLS-ST) to permit the use of a smaller sanitary connection.

Manufacturing Range of Reverse Buckling Disks

All reverse bucking disks may be offered with a 0%, 5% or 10% manufacturing range. The range is applied to the minus side of the requested burst pressure. 

Example: If a disk is ordered with 75 psig (5.17 barg burst pressure and a 10% manufacturing range, it will be tagged at a burst pressure between 67.5 psig (4.65 barg) and 75 psig (5.17 barg). 

Burst Tolerance of Reverse Buckling Disks

Burst tolerance is the maximum variation from the tagged burst pressure. 

Disk tagged above 40 psig/2.76 barg.................... 5% 

Disk tagged at 40 psig/2.76 barg and below.......... 2 psig/0.138 barg

Sanitary Rupture Disks Specifications
Type
Nominal Size
inch (mm)
Burst Pressure psig    (barg)  
Maximum Operating Pressure (7)
Cycle Life Resistance to Fatique
Service 
Holder Type (8)
GFR-S (5) 
1.0 (25) - 3 (80)  
11.5 (0.79) - 300 (20.68)
90% 
GOOD  
GAS/LIQUID (1)  
GR-C  
JRS-S (2)
JRS-ST
1.0 (25) -4 (100)
16 (1.10) - 180 (12.40)  
90%
GOOD  
GAS (3)  
SR-C  
GLRS (5)
RLS-S (2)
RLS-ST
1.5(40)  

1.0 (25) - 4 (100)

175 (12.0) - 350 (24.13)  65 (4.48) - 275 (18.96)  
90%
GOOD  
GAS/LIQUID (4)  
GR-C
SR-C
SR-C  
D-ST  
 DV-ST   
DD-ST (6)
1.0 (25) - 4 (100)
8 (0.55) -   275 (18.96)  
80%
GOOD  
GAS/LIQUID  
FF-C  
AV-ST (6)
2 (50) -   4 (100)
4.25 (0.29) - 40 (2.76)  
60%
FAIR  
GAS/LIQUID  
FF-C  
VKB (6)  
P/VKB
2 (50) - 8(200)
5.50" WC - 44" WC  

13.75mbarg - 110mbarg 

7 (0.48) - 170 (11.70)  

80%
FAIR  
GAS/LIQUID  
KB-C  

PKB-C

AVB-ST (6) -
1 (0.07)  -  10 (0.69)  
- FAIR -
VB-C  

Other sizes available for JRS, RLS and D type disks

Notes:

  1. For full liquid service contact BS&B
  2. Standard material for JRS and RLS Type disks is 316 SS contact BS&B for other materials and burst pressures.
  3. May be used in liquid  service with adequate volume of gas/vapor above liquid and below disk.
  4. For full liquid or gas/vapor service.
  5. GFR-S and GLR-S disk for use with the GR-C, FM-C or FT-C.
  6. Two-way acting disk for vacuum relief and overpressure relief.
  7. Recommended maximum operating pressure as a percentage of burst pressure.
  8. SR-C, FF-C, KB-C, PKB-C, VB-C and PVB-C disk holders are also available with butt or tank weld end connections.
Type GCR-ST Reverse Buckling Disk

The GCR-ST is an innovative design using SAFT technology (Structural Apex Forming) offering a wide range of burst pressures for sanitary/aseptic applications in the pharmaceutical, biotechnology and food industries.

Features and Benefits

  • One disk design for gas and liquid service
  • Fail-safe design - Damage-Safety ratio less than or equal to 1
  • Low to high Burst Pressures
  • Ideal for CIP/SIP Service*
  • Installed with Integral Sanitary/Aseptic Gaskets
  • 8 to 16 micro-inch typical disk surface finish
  • Minimum dead space between process fluid and the disk
  • Suitable for operating pressures up to 90% of Marked Burst Pressure** or 95% of the specified minimum burst pressure (CEN standard pending)
  • Designed for non-fragmentation
  • Standard Manufacturing Design Range, zero%, optional - 5%, -10%
  • Withstands full vacuum at all Burst Pressures
  • SASTM (Sanitary Alert Sensor) with leak sensing option available
  • Integral burst disk sensor option
  • Worldwide patents pending

*Clean/Steam in Place
**At marked burst pressures of 40 psig (2.76 barg) and below, the recommended maximum operating pressure is 90% of the marked burst pressure, less 2 psig (0.138 barg) tolerance.

GCR-ST Disk Specification Min/Max Burst Pressure at 72o F (22o) Psig (Bar)

Sanitary Fitting Nominal Disk Size Burst Pressure Overall Height
(A)
OD
(B)
in mm Minimum Maximum in
mm
in
mm
1.5 40 10 0.69 300 20.7 1.62 41 1.98 50.4
2 50 10 0.69 300 20.7 1.62 41 2.52 63.9

Other Burst Pressures may be available, consult BS&B Safety Systems, Inc. or BS&B Safety Systems Ltd.

Design

The GCR-ST family of reverse buckling disks is designed with a circular score line located at the edge of the domed area. At the marked burst pressure the disk's dome reverses and opens by shearing around the circular score line. The GCR-ST provides very low burst pressures with excellent opening characteristics. An integral energy absorbing hinge located on the downstream side of the disk enables the disk to perform in gas or liquid service with superior flow performance. The hinge design interacts with the holder outlet bore to retain the disk on opening, avoiding fragmentation.

SAFT Technology: Damage Safety Ratio Less Than or Equal to 1

Structural Apex Forming, the precision indentation present in all GCR-S Rupture Disks, combined with the unique energy absorbing hinge design, ensures that a damaged disk will rupture at or below the marked burst pressure.

Marked Burst Pressure

The ASME Code requires that the marked burst pressure is within the manufacturing design range and is determined such that the sample burst test pressures are within the specified tolerance (+/- 2 psig at or below 40 psig or +/- 5% above 40 psig). BS&B Safety Systems, Inc. and BS&B Safety Systems Ltd. will exceed ASME code requirements by continuing to use the average of the burst test values as the marked burst pressure (for -5% and -10% Manufacturing Design Range) and requiring this average to fall within the manufacturing design range. This is in accordance with previous editions of the code and will maintain consistency in burst pressure marking for the user.

Sensors

The Sanitary Alert Sensor is for use between standard sanitary /aseptic fittings to provide warning of a burst rupture disk (bursting disc). Leaking disk detection is also available; consult BS&B Safety Systems, Inc. or BS&B Safety Systems Ltd. for details.

The GCR-ST and GCR-SMT disks are also available with integral sensors to provide warning of a burst rupture disk (bursting disc), specify types GCR-SST and GCR-SMST.

Manufacturing Design Range

Manufacturing Design Range is a range of pressures within which the marked burst pressure must fail to be acceptable for a particular requirement as agreed upon between the Rupture Disk (Bursting Disc) Manufacturer and the user or his agent.

The standard Manufacturing Design Range for the GCR-ST disk is 0%. The user's requested burst pressure will be the Marked Burst Pressure. Optional Manufacturing Design Ranges of -5% and -10% may be selected as operating conditions permit. The Manufacturing Design Range is applied to the minus side only of the requested burst pressure.

Flow Performance

Flow Resistance Factor KR may be used to determine the relieving capacity of a system according to the ASME and CEN (pending) codes. Individual KR values have been established for both gas and liquid service for the disk. Minimum Net Flow Area (MNFA) for each disk size is provided to assist with ASME sizing calculations. Net Relief Area has been provided for sizing according to European and International standards.

KR Values Minimum Net Flow Area (MNFA), NRA Values

Disk Size 1 1/2" 40 mm 2" 50 mm
KR 1.95 1.25
*MNFA in2 1.22 2.31
**NRA cm2 7.35 14.12

*Use MNFA in2 when sizing according to ASME Code, para UG-127(a)(2)(a)
**Use NRA cm2 (Net Relief/Area) when sizing according to European standards

The KR values indicated are for gas service. The GCR-ST disks have been performance tested for both gas and liquid, contact BS&B Safety Systems, Inc. or BS&B Safety Systems Ltd. for liquid service KR values. CE marking of bursting disks will be offered on completion of validation to the European Code.

Gaskets

The GCR-ST is supplied with FDA approved Silicone, Viton (white or black), EPDM (white or black) and Tef-Steel gaskets ensuring correct and leak-tight installations with type GR-CT fitting or FM-CT disk holder.

Material Minimum Service Temperature Maximum Service Temperature
Silicone -67F (-55C) 450F (232C)
Viton -40F (-40C) 400F (204C)
EPDM -67F (-55C) 300F (149C)
Tef-Steel -20F (-29C) 450F (232C)

Materials

The disk is available in 316LSS as standard. Alternative materials are available on request.

Liners

Liners are available in all sizes as optional on the process side of the disk. FEP or PTFE are generally used.

Temperature Range
Liners F C
FEP -40 to 400 -40 to 204
PTFE -40 to 500 -40 to 260

GCR-ST Disk Types

GCR-ST and GCR-SST with approved gaskets are installed between a standard inlet ferrule and the GR-CT outlet fitting ensuring correct direction of disk and leak tight installation.

The GCR-SMT and GCR-SMST have a symmetric gasket configuration on both sides of the disk and fit between standard Tri-Clamp (or equivalent) ferrules.

The GCR-SET is installed in a FM-CT Safety Head. The inlet of the FM-CT Safety Head is welded to the vessel wall and permits the rupture disk (bursting disc) to be installed flush with the interior wall of the vessel. The space between the process fluid and the disk is minimized.

GCR-SWT is a welded ferrule assembly, the disk is welded between standard ferrules.

Installation

The GCR-ST and FM-CT holder designs ensure correct direction and leak tight Rupture Disk (Bursting Disc) installation. We recommend the assembly of GCR-ST Rupture Disks into their respective holders using a Tri-Clamp 13 MHHS Clamp (or equivalent) with a hexagonal nut enabling control of installation torque. The GCR-ST disk range, using SAFT technology, exhibits minimum sensitivity to changes in clamp loading on the disk induced by service temperature variations. However an adequate clamping load to maintain leak tightness must be maintained.

Type GLR-S Reverse Buckling Disk

The type GLR-S is available in 1.5" (40 mm) nominal size for use in 1.5" GR-C fitting or FM-C/FT-C holders. The type GLR-S disk is available with burst pressures as shown below.

Type FM-C Rupture Disk (Bursting Disc) Holder

The inlet of the FM-C disk holder is welded to the vessel wall, and permits the rupture disk (bursting disc) to be installed flush with the interior wall of the vessel. As the dead leg is eliminated, the space between the process fluid and the disk is minimized. The holder is available in 316L SS; clamp 304 SS and for disk/clamp sizes 1"-3".

The FT-C Rupture Disk (Bursting Disc) Holder

The FT-C holder may be used to replace a conventional sanitary fitting "Tee" on which GFR-SE disk is installed with the advantage of minimizing the dead space between the process fluid and the rupture disk (bursting disc). The FT-C holder permits the rupture disk (bursting disc) to be located adjacent to the process flow. The self-cleaning and sweeping action of the fluid minimizes possible product accumulation on the surface of the disk. The FT-C holder is available in 316 SS , for 1" - 3" disk /clamp sizes.

Type FM-C
Disk Size Clamp Size C D
inch mm A B inch mm inch mm
1" 25 1" 3 2.470 62.7 3.224 81.9
1.5" 40 1.5" 3 2.470 62.7 3.224 81.9
2" 50 2" 3 2.470 62.7 3.224 81.9
3" 80 3" 4 2.470 62.7 4.256 108.1

  

Type   FT-C 
DISK/CLAMP CONNECTION SIZE A B C D
inch mm inch mm inch mm inch mm inch mm
1 25 3.97 101 3.0 76 4.0 102 6.00 152
1.5 4.0 3.97 101 3.0 76 4.0 102 6.00 152

For larger and alternative sanitary fitting sizes, consult BS&B

Type JRS-S & JRS-ST Reverse Buckling Disks

The JRS-S and JRS-ST are reverse buckling disks which incorporate a teeth ring attached to the downstream side of the disk. When overpressure occurs, disk rupture is achieved by the disk reversing and opening on the teeth-ring providing full relief opening.

Features and Benefits:

  • For low burst pressures.
  • Excellent for gas/vapor service*.
  • Operating pressures up to 90%+ of rated pressure.
  • Designed for non-fragmentation.
  • Excellent in pressure cycling or pulsating conditions.
  • Withstands full vacuum without vacuum support.
  • Damage ratio of 1.5 or less. If damaged when installed, it will burst at or less than 1.5 times its rated pressure.

* May be used in liquid service provided there is an adequate volume of vapor above the liquid and below the disk.

+ At rated burst pressures of 40 psig (2.76 barg) and below, the recommended minimum operating pressure is 90% of the rated burst pressure less 2 psig (0.138 barg) tolerance.

Manufacturing Range

Disks in sizes from 1.5" (40mm) are available with a 0%, -5% and -10% manufacturing range, and the 1" (25mm) disk is available with a -2%,-5% and -10% manaufacturing range.

   TYPE JRS-S & JRS-ST Disk Specifications
Standard Material 316* 
Minimum-Maximum Burst pressure @ 72 F (22 C)
SIZE MINIMUM MAXIMUM
inch
mm
psig
barg
psig
barg
1
25 
24 1.65
180 
12.40
1.5
40 
22 1.52
150 
  10.34 
2
50 
20 1.38
120 
  8.27 
3
80 
18 1.24
80 
  5.52 
4
100 
16 1.10
70 
  4.82 

* Other disk sizes and materials available on request.

FEP/PTFE liners are available on the process side of the disk in sizes from 2" (50mm) and above. Maximum temperature for FEP/PTFE is 500 F (260 C), maximum temperature for 316 SS is 750 F (399 C).

Type RLS-S & RLS-ST Reverse Buckling Disks

The RLS-S and RLS-ST are reverse buckling disks with a circular score-line around the circumference of the disk on the downstream side. A metal hinge is attached to the disk on the downstream side to prevent fragmentation. When overpressure occurs disk rupture is achieved by reversing and opening along the circumferential score-line providing full relief opening.

Features and Benefits

  • Excellent for full liquid or gas/vapor service.
  • Operating pressure up to 90% of rated pressure.
  • Designed for non-fragmentation
  • Excellent in pressure cycling or pulsating conditions
  • Withstands full vacuum without vacuum support.
  • Damage ratio of 1.5 or less. If damaged when installed, it will burst at or less than 1.5 times its rated pressure.

Manufacturing Range

The disks are available with -5% and -10% manufacturing range; 0% manufacturing range is available for certain rupture pressures and sizes.

Note: Refer to SR-C holder details on the sanitary SR-C holder specifications page below when RLS-S and RLS-ST are to be selected

TYPE RLS-S & RLS-ST Disk Specifications
Standard Material 316*
 
Minimum-Maximum Burst Pressure @ 72 F (22 C)
  SIZE MINIMUM   MAXIMUM
inch mm psig barg psig barg
1
25 
175 
12.00 
275
18.96 
1.5
40 
145 
10.00 
225
15.51 
2
50 
115 
7.93 
175
12.06 
3
80 
75 
5.17 
125
8.61 
4 100  65  4.48  100 6.89 

Other disks sizes and materials available on request.

FEP/PTFE liners are available on the process or downstream side of the disk in all sizes. Maximum temperature for 316 SS is 750o F (399o C), maximum temperature for FEP/PTFE is 500o F(260o C).

Type GLR-S Reverse Buckling Disk

This is a type RLS reverse buckling disk supplied with an integral sanitary gasket of FDA approved silicone, Viton or EPDM. The unique design of the gasket ensures correct and leak-tight installation with the GR-C fitting or FM-C/FT-C disk holders. The type GLR-S disk is available for burst pressure applications above 300 psig (20.68 barg) which cannot be met by the type GFR-S disk. It is available in 1 1/2" (40mm) size. It is available with an FEP/PTFE liner which covers the disk and gasket on the process side.

Type GLR-S Disk Specifications
SIZE RELIEF AREA MINIMUM MAXIMUM
inch mm in2 mm2 psig barg psig barg
1.5 40 0.79 510 175 12.0 350 24.13

Sanitary SR-C Holder Specifications

Sanitary SRC Holder Dimensions for Types JR-S/JRS-ST, RLS-S/RLS-ST 

Reverse Buckling Disks

DISK/HOLDER SIZE 
CLAMP CONNECTION SIZE/TUBE O.D. (inch) 
DISK TYPE HEIGHT *A
inch
mm 
@ Inlet @ Disk @ Outlet inch
mm 
1.0 
25 
 1.5 

  2.0 

2.0

2.0

 1.5 
2.0
-S 

-S 

   3.25 

3.0

83 

76 

1.5 
40 
  2.0 

  2.0 

 2.0 
2.5
 2.0 
2.0
-ST 

-S 

  3.0 
 3.0
76 

76 

2.0 
50 
2.0

  3.0 

3.0

3.0 
3.0 
4.0
 2.0 
 3.0 
3.0
-ST 

-ST

-S 

   4.19 

   3.69 
4.0

 106 

94

 102 

3.0 
80 
3.0 

4.0 

 4.0 
4.0
 3.0 
4.0
-ST 

-ST 

  4.0 
 4.0
 102 

102

4.0
100
4.0 
6.0
  6.0 
 6.0
4.0 
6.0
-S 
-S
 5.5 
5.5
  140  
 140

*JRS-ST not available in 1.5" size for 2" clamp size. Consult BS&B for alternative inlet/outlet clamp size options and for sizes above 4" (100mm). Standard SR-C holder material is 316 SS with 304 SS clamp.

Type D-ST & DV-ST Composite Rupture Disks

The D-ST composite rupture disk (bursting disc) consists of a domed slotted metal top section and a plastic or metal seal located on the concave or process side of the top section.

Features and Benefits

  • Excellent for liquid or gas/vapor service
  • Operating pressures up to 80% of rated pressure.
  • FEP/PTFE liner provides a seal and corrosion resistance.

Type DV-ST* Disk

When vacuum is present, the disk is fitted with a vacuum support and a DV-ST type disk must be specified.

Type DD-ST* Disk

The type DD-ST may be used where two-way relief is required. This disk consists of two slotted metal sections with a plastic seal that floats between both sections. The burst pressure in one direction may be up to twice the burst pressure in the opposite direction with full relief opening in both directions when bursting occurs. The available burst pressures are the same as those of the equivalent size D-ST disk, and has identical performance features.

* The DV-ST and DD-ST construction may not be suitable for all sanitary applications, consult BS&B. 

Types D-ST and DV-ST Disk Specifications
Standard Material 316 SS FEP/PTFE Seal
Minimum-Maximum Burst Pressure @ 72 F (22 C)
SIZE MINIMUM MAXIMUM
inch mm psig barg psig barg
1
25 
44 3.03 275
18.96 
1.5
40 
31 2.14 225
15.51 
2
50 
15 1.03 175
12.06 
3
80 
11 0.76 125
8.61 
4 100  8 0.55 100
6.89 

Other sizes and materials available upon request. Temperature range minimum -40o F (40o C), maximum 500o F (260o C) with FEP/PTFE seal.

Manufacturing Range and Burst Tolerance

Example: If a disk is requested with 17 psig (1.17 barg) burst pressure, the disk will be tagged at a burst pressure between 15 psig (1.03 barg) and 21 psig (1.45 barg).

Marked Rupture Pressure Rupture Tolerance
2 psig (0.14 barg)- less than 15 psig (1.03 barg) +/- 1.5 psig (0.1 barg)
15 psig (1.03 barg)-less than 40 psig (2.76 barg) +/- psig (0.14 barg)
40 psig (2.76 barg) and above +/- 5%

  

Manufacturing Range
Specified Pressure Rating
Test specimens must rupture within limits shown below of  the specified pressure
psig
barg 
plus
minus
psig 
barg 
psig 
barg
2.5-3.5 
0.17-0.24 
0.07 
0.07 
4-6 
0.27-0.42 
0.14 
0.07 
7-10 
0.48-0.69 
2.5 
0.17 
1.5 
0.10 
11-16 
0.76-1.1
0.21 
0.14 
17-25 
1.17-1.72 
0.28 
0.14 
26-40 
1.79-2.76 
0.35 
0.21 
41-65 
2.82-4.48 
0.42 
0.28 
66-100 
4.55-6.89 
0.62 
0.35 
101-150 
6.96-10.34
12 
0.83 
0.41 
151-200 
10.41-13.79 
16 
1.10 
0.62 
201-350 
13.86-24.13 
23 
1.59 
12 
0.83 

Reduced manufacturing ranges of zero, 1/4 and 1/2 are available upon request.

Type AV-ST Composite Rupture Disk (Bursting Disc)

The AV-ST is a flat composite disk designed to relieve overpressure in both directions at the same burst pressure. The disk may be used in either gas or liquid service.

Features and Benefits

  • For low burst pressures.
  • Operating pressures up to 60% of the minimum burst pressure.
  • FEP/PTFE seal.

Burst Pressure Range

All AV-ST* type disks are marked on the disk tag with a minimum/maximum burst range. In the case of a requested burst pressure up to 25 psig (1.72 barg) the burst range will be 1.25 psig (0.09 barg) of the requested burst pressure, and above 25 psig (1.72 barg) 3 psig (0.21 barg). The manufacturing range and burst tolerance are included in this minimum/maximum burst range.

Example: Type AV-ST burst range minimum 6 psig (0.41 barg)-maximum 8.5 psig (0.59 barg) at 72o F (22o C), 3 inch (80mm).

AV- ST Composite Disk  
Standard Material 316 SS FEP/ PTFE SEAL Minimum - Maximum Burst Pressure @ 72 F ( 22C)
SIZE MINIMUM MAXIMUM
inch mm psig barg psig barg
2 50 6.25 0.43 40 2.76
3 80 5.25 0.36 35 2.41
4 100 4.25 0.29 30 2.10

Temperature range minimum -40o F (-40o C) to maximum 500o F (260o C), with FEP/PTFE seal. Other sizes and materials available on request. * The construction of the disk may not be suitable for all sanitary applications. Consult BS&B.

Sanitary FF - C Holder Dimensions For Types DV-ST , D-ST , DD -ST and AV-ST Composite Disks
DISK/HOLDER SIZE  CLAMP CONNECTION SIZE/TUBE O.D. (inch)  HEIGHT
inch
mm 
@Inlet
@Disk 
@Outlet inch
mm 
1.0
25 
1.5 
1.5 
1.5 3.0
76 
1.5
40 
2.0 
2.0 
2.0 3.0
76 
2.0
50 
3.0 
3.0 
3.0 3.0
76 
3.0
80 
4.0 
4.0 
4.0 4.0
102 
4.0
100 
6.0 
6.0 
6.0  5.5 
140 

Consult BS&B for alternative inlet and outlet clamp size options. Type AV-ST available in sizes 2" (50mm) and above sizes only.

Standard holder material is 316 SS with 304 SS clamp.

Type VKB & P/VKB Two-Way Relief Disk

The VKB rupture disk (bursting disc) is a two-way acting disk designed to prevent implosion under vacuum or overpressure. The disk may be used in either gas or liquid service. The VKB rupture disk (bursting disc) installed in the KB-C holder meets the requirements of the American 3A sanitary standards.

Vacuum Relief

At the rated vacuum relief pressure the disk seal separates from the perforated metal section to snap against a set of knifeblades located in the disk holder inlet cutting the seal into three segments. The perforated metal section remains intact, and flow through the holes in the metal section relieves the vacuum.

Burst Range 

The disks are available with a burst range of +/-1.5 in WC (3.75 mbarg) for pressure up to 8.0 in WC (20 mbarg) and  +/- 20% for higher pressures. All tolerances are included in the burst range. Example: a disk with a specified vacuum relief pressure of 7.0 in WC (17.5 mbarg) will be marked on the disk tag as minimum 5.5 in WC (13.75 mbarg) - maximum 8.5 in WC (21.25 mbarg).

Overpressure Relief

The disk relieves overpressure by opening fully along the metal slits in the perforated section. The disk offers a smooth surface towards the process which prevents product accumulation.

Pressure Range for Vacuum and Overpressure Relief for Disk Type VKB
at 72 F (22 C)
DISK SIZE
VACUUM RELIEF
VACUUM RELIEF AREA 
OVERPRESSURE RELIEF*
Minimum
Maximum 
Minimum Maximum
inch
mm
in WC   
mbarg 
in WC    
mbarg
in2
mm2
psig
barg
psig
barg
2.0
50 
7.5
18.75 
44.0
110.0 
1.5
967 
18 
1.24
170 
11.7 
3.0
80 
6.5
16.25 
30.0
75.0 
3.57 
2303 
16 
1.10
170 
11.7 
4.0
100 
5.5
13.75 
30.0
75.0 
5.93 
3825 
13 
0.9
119 
8.2 
6.0
150 
5.5
13.75 
30.0
75.0 
12.30 
7935 
13 
0.9
90 
6.2 
8.0
200 
5.5
13.75 
20.0
50.0 
18.50 
11936 
0.48
55 
3.8 

* In overpressure relief the disk opens fully.
Above burst pressures are at 72o F (22o C). Consult BS&B for other burst pressures.
Temperature range minimum -40o F (-40o C) to maximum 250o F (120o C) in overpressure conditions, maximum 175o F (80o C) in vacuum operating conditions. Standard materials are 316 SS with FEP/PTFE seal. Other materials available upon request.

Manufacturing Range

The disks are available with a +/- 2 psig (0.138 barg) or minus 10% manufacturing range depending on the burst pressure.

Tagged Burst Pressure Manufacturing Range
Up to 40 psig (2.76 barg) +/- 2   psig (0.138 barg)
above 40 psig (2.76 barg) -10 % 

Example: A burst pressure of 58 psig (4 barg) is requested with a 10% manufacturing range. The values of the burst tests carried out during manufacture will lie between the 52.2 psig (3.6 barg) and 58 psig (4 barg). The average of  the test values will be marked on the disk tag.

Burst Tolerance

Tolerances are the maximum variation from the burst pressure shown on the disk tag.

Tagged Burst Pressure Burst Tolerance
psig (barg)
6 - 8 (0.41 - 0.55) 20%
9 - 12 (0.62 - 0.83) 15%
13 - 17 (0.90 - 1.17) 10%
18 - 25 (1.24 - 1.72) 7%
26+ (1.79 and above) 5%

Operating Pressure

The rupture disks (bursting discs) may be subjected to the following operating pressures without affecting the disk's service life.

Vacuum Relief: up to 80% of the minimum of burst range.

Overpressure Relief: up to 80% of the tagged burst pressure.

Type P/VKB Rupture Disk (Bursting Disc)

Type P/VKB rupture disk (bursting disc) is a two-way acting disk designed to relieve light overpressure or prevent implosion under vacuum. The disk may be used in either gas or liquid service. The type P/VKB is the inverted style of the type VKB disk.  

Overpressure Relief

At the rated burst pressure the disk seal separates from the perforated metal section to snap against the knife-blades located in the disk holder oulet, cutting the seal into three segments. The perforated metal section remains intact and flow through the holes in the metal section relieves the overpressure.
 
Pressure Range for Light Overpressure and
Vacuum Relief for Disk Type P/VKB at 72 F (22) C
OVER   PRESSURE RELIEF
DISK SIZE VACUUM RELIEF RELIEF AREA
inch mm MINIMUM MAXIMUM in2 mm2
in WC mbarg in WC mbarg
2.0 
50 
7.5
18.75
44.0
110.0 
1.5
967 
3.0 
80 
6.5
16.25
30.0
75.0 
3.57 
2303 
4.0 
100 
5.5
13.75
30.0
75.0 
5.93 
3925 
6.0 
150 
5.5
13.75
30.0
75.0 
12.30 
7935 
8.0 
200 
5.5
13.75
20.0
50.0 
18.50 
11936 

Above burst pressures are at 72o F(22o C), consult BS&B for other burst temperatures. Standard materials are 316 SS with a FEP/PTFE seal. Other material available upon request. Temperature range -40o F (-40o C) to maximum of 175o F(80o C).

Burst Range

The disks are available with a burst range of +/- 1.5 in WC (3.75 mbarg)   for pressure up to 8.0 in WC (20 mbarg) and       +/- 20% for higher pressures. All tolerances are included in the burst range. A disk with a specified burst pressure of 16.0 in WC (40 mbarg) will be shown on the disk tag as minimum 12.8 in WC (32 mbarg) - maximum 19.2 in WC (48 mbarg).

Operating Pressure

The system may operate up to 80% of the minimum of the burst range without affecting the service life of the disk.

Vacuum Relief

The disk may be used also to relieve vacuum depending on specific requirements.

KB-C and PKB-C Holders

Asymmetric alignment pins in the holder mate with locating holes in the rupture disk (bursting disc) for proper installation. The standard holder material is 300 series stainless steel, the knife blade material 301 SS.

Sanitary KB-C/PKB-C Holder Dimensions For Types VKB,  P/VKB Vac-Saf Rupture Disks 
DISK/HOLDER SIZE CLAMP CONNECTION SIZE/TUBE O.D. (inch) HEIGHT A
inch mm @ Inlet @ Disk @ Outlet inch mm
2
50 
3
76 
3
80 
3
76 
4
100 
4
102 
6
150 
4
102 
8
200 
10 
10 
10 
4.5 
  114.3

Consult BS&B for alternative clamp size options.

Type AVB-ST & P/AVB-ST Two-Way Relief Disks

The type AVB-ST rupture disk (bursting disc), like the VKB disk is a two-way acting disk designed to prevent implosion under vacuum or overpressure. This disk meets the medium range vacuum and overpressure relief requirements that cannot be met by the VKB disk.

Vacuum Relief
Burst Range

T'he disks are available with a minimum/maximum burst range which includes the manufacturing range and burst tolerance.  A 4" (100mm) disk with a  specified vacuum relief pressure of 5 psig (0.34 barg) will be marked on the disk tag as minimum 4.5 psig (0.31 barg) to maximum 5.5 psig (0.38 barg).

Overpressure Relief
Manufacturing Range

The disks are available with a 0%, -5% or -10% manufacturing range. If a disk is ordered with a 50 psig (3.45 barg) burst pressure and -10%  manufacturing range, it will be tagged at a burst pressure between 45 psig (3.1 barg) and 50 psig (3.45 barg).

Pressure Range for Vacuum and Overpressure Relief for Disk Type AVB-ST at 72 F (22 C)
DISK SIZE VACUUM RELIEF (psig/barg) OVERPRESSURE RELIEF (psig/barg)
in mm MINIMUM MAXIMUM BURST RANGE RELIEF AREA MINIMUM MAXIMUM RELIEF AREA 
psig barg psig barg psig barg in2 cm2 psig barg psig barg
50 
5
0.345 
10 
0.689
.5
.0345 
1.98 
12.8 
0.552
100 
6.89
Full 
3
80 
3
0.206 
10 
0.689
.5
.0345 
2.03 
13.1 
0.345
100 
6.89
Full 
4
100 
2
0.138 
10 
0.689
.5
.0345 
3.58 
23.1 
0.345
100 
6.89
Full 
6
150 
1.5
0.103 
0.413
.25
.0172 
5.93 
38.25
0.207
85 
5.86
Full 
8
200 
0.069 
0.413 
.25
.0172 
9.25 
59.68 
0.207
65 
 4.48 
Full

Standard material is 316 SS with a PTFE seal and Kapton vacuum control ring. Other materials available on request.
Temperature range minimum -40 F (40 C),  maximum 400 F (204 C).

Burst Tolerance
Tolerances are the maximum variation from the rated burst pressure shown on the tag.

Tagged Burst Pressure Rating 
PSIG 
BARG 
BURST TOLERANCE%
3-5 
0.21-0.35 
25
6-8 
0.41-0.55 
20
 9-12
0.62-0.83 
15
13-17 
  0.9-1.17
10
18-25 
1.24-1.72 
7
26-up 
1.8 - up 
5

Operating Pressures

The rupture disks (bursting discs) may be subjected to the following operating pressures without affecting the disk's service life.

Overpressure Relief:  up to 70% of the disk's tagged burst pressure.
Vacuum Relief:          up to 60% of the minimum of the burst range.

Type P/AVB-ST Disk

The P/AVB-ST disk is the inverted form of the type AVB-ST disk, and meets the medium range of overpressure and vacuum relief requirements that cannot be met by the P/VKB disk.

Overpressure Relief

Burst Range

The disks are available with a minimum - maximum burst range which includes the manufacturing range and burst tolerance. A 3" (80mm) disk with  a specified burst pressure of 7 psig (0.48 barg) will be marked on the disk tag as minimum 6.5 psig (0.45 barg) maximum - 7.5 psig (0.52 barg).

Operating Pressure

The system may operate up to 60% of the minimum of the burst range without affecting the service life of the disk.

Vacuum Relief

The disk may be used also to relieve vacuum depending on specific requirements.

Pressure Range for Light Overpressure Relief for Disk type P/AVB-ST
at 72 F (22 C)
DISK SIZE
MINIMUM
MAXIMUM 
BURST RANGE
RELIEF AREA
inch
mm
psig
barg
psig
barg
psig
barg
in2
cm2
2
50 
5
0.345
10
0.689 
.5
.0345 
1.98 
12.8
3
80 
3
0.206
10
0.689 
.5
.0345 
2.03 
13.1
4
100 
2
0.138
10
0.689 
.5
.0345 
3.58 
23.1
6
150 
1.5
0.103
6
0.413 
.25
.0172 
5.93 
38.25
8
200 
1
0.069
0.413 
.25 
.0172 
9.25 
59.68

Temperature range minimum -40o F (-40o C), maximum 400o F(204o C).

VB-C and P/VB-C Holders

Assymetric alignment pins in the holder mate with locating holes in the rupture disk (bursting disc) for proper installation. The standard holder material is 316 SS.

Sanitary VB-C and P/VB-C Holder Dimensions for Type AVB-ST and P/AVB-ST Rupture Disks
DISK/HOLDER SIZE CLAMP CONNECTION SIZE/TUBE O.D. (inch) HEIGHT
inch mm @ Inlet @ Disk @ Outlet inch mm
2
50 
4.0 
102
3
80 
4.0 
102
4
100 
5.5 
140
6
150 
8
*
8
200 
10 
10 
10
*
*

Consult BS&B for alternative clamp size options and height dimensions.

VSP & VSE Explosion Vents

Explosion vents protect against damage in the event of deflagrations of combustible materials. These explosion vents of single section steel construction are supplied with a smooth internal surface finish. Solid white silicone gaskets are fixed to the vent flange area and FDA approved RTV sealing material applied to the vent perimeter to achieve a sanitary/aseptic construction.

The vents are available in a wide range of sizes in either circular or rectangular designs. For more information, see catalog 77-8015.

Typical equipment protected includes silos, spray dryers, dust collectors conveyors.

SAS Sanitary Alert Sensor

The SAS Sanitary Alert Sensor provides immediate warning of a ruptured disk when used with a BS&B Burst Disk Monitor (Catalog 77-1009) or other suitable electrical equipment. The sensor is supplied with gaskets for installation between sanitary fittings on the downstream side of the rupture disk (bursting disc). Gasket materials available are Viton (white or black), EPDM (white or black) and silicone. Leaking disk detection is also available, contact BS&B for details.

The sensor is classified as a simple apparatus, and is suitable for use in hazardous locations provided it is used with other certified electrical apparatus (i.e. a Zener barrier) and properly installed and maintained. Maximum voltage 24Vdc. Maximum current 500mA.

Sanitary Clamps & Accessories

BS&B rupture disks (bursting discs) are installed between sanitary holder fittings and fixed in position using Tri-Clover clamp model 13 MHHS  (or equivalent) with hexagonal torque nut. A two-piece high pressure clamp model 13 MHP will be used with high burst pressure disks. Spool, tank or butt weld ferrule accessories are available.