Products > Replaced Products > Multi-Gard (MG)    Print this product datasheet
 
 
Multigard is a compression-loaded radially scored reverse bursting disc, which brings the highest operating performance characteristics to the user. It is ideal for many applications and particularly suitable for relief valve isolation. Elfab's unique offset tag and System-Loc arrangement offer the Multigard user foolproof installation.
 
 
  • Excellent operating performance
  • Non fragmenting design
  • Superior cyclic performance
  • Foolproof and safe installation
  • Ideal for relief valve isolation
  • Smooth operating surface
Specifications
SIZE RANGE
25 to 500 mm (1 to 20 ins)
BURST PRESSURE RANGE
2.0 to 40 bar g (30 to 580 psig)
TEMPERATURE RANGE
-200 to 500C (-330 to 930F)
MAXIMUM OPERATING RATIO
95%
FRAGMENTATION ON BURST
non fragmenting design
RELIEF VALVE ISOLATION
excellent
VACUUM SERVICE
suitable
FLUID COMPATIBILITY
gas, vapour or gas cap only
TORQUE-SENSITIVE
no
CYCLE LIFE
excellent
MATERIAL RANGE
good
REVERSAL RATIO
not applicable with offset tag + System-Loc
DAMAGE RATIO
<1 (fail-safe)
LEAK TIGHTNESS
excellent
PERFORMANCE TOLERANCE
5%*(with no manufacturing range)

Pressure and Solutions Intelligence
Elfab is an ISO 9001:2000 Certified Company and all Elfab’s bursting discs are manufactured in-house to the highest standards, being tested and certified in accordance with BS2915, the British Standard for bursting discs. To ensure the correct performance of a bursting disc, it must be used in its correct holder, as specified by the bursting disc manufacturer.

As the temperature seen by a bursting disc changes its burst pressure and performance will change. As a result of extensive testing, Elfab can advise on these changes, or on other technical matters, such as discharge requirements, material selection and corrosion resistance, customised designs and burst detection.

Specifications and Performance
BURST PRESSURE RANGE in barg (psig) at 20 °C (68 °F)
Nominal Size
Nickel
Stainless Steel/ Inconel
mm
inch
Min
Max
Min
Max
25
1
8.0(116)
30(435)
20(290)
40(580)
40
5.0(72.5)
30(435)
15(218)
30(435)
50
2
4.0(58)
30(435)
10(145)
30(435)
65
4.0(58)
25(363)
10(145)
27(392)
80
3
4.0(58)
20(290)
10(145)
25(363)
100
4
3.0(43.5)
15(218)
8.0(116)
25(363)
150
6
2.5(36.3)
14(203)
6.0(87)
20(290)
200
8
2.5(36.3)
13(189)
5.0(72.5)
15(218)
250
10
2.0(29)
12(174)
5.0(72.5)
15(218)
300
12
2.0(29)
12(174)
3.0(43.5)
15(218)
350
14
2.0(29)
10(145)
2.5(36.3)
12(174)
400
16
2.0(29)
8.0(116)
2.5(36.3)
10(145)
450
18
2.0(29)
7.0(102)
2.5(36.3)
8.0(116)
500
20
2.0(29)
6.0(87)
2.0(29)
8.0(116)

PERFORMANCE TOLERANCE (ZERO MANUFACTURING DESIGN RANGE)
Burst Pressure
Tolerance
Entire Range
+/- 5%

STANDARD TEMPERATURE RANGE °C (°F)
Material Temperature Limits °C (°F)
Material
Minimum
Maximum
Stainless Steel
-80 (-112)
480 (900)
Inconel
-80 (-112)
600 (1112)
Nickel
-80 (-112)
400 (750)

FREE FLOW AREA / MINIMUM NET FLOW AREA (MNFA)
Nominal Size
mm
inch
mm2
inch2
25
1
507
0.79
40
1257
1.95
50
2
2027
3.14
65
3319
5.14
80
3
5027
7.79
100
4
8108
12.57
150
6
17674
27.39
200
8
31420
48.70
250
10
49094
76.10
300
12
70695
109.58
350
14
96224
149.15
400
16
125680
194.80
450
18
159064
246.55
500
20
196375
304.38

HOLDER DIMENSIONS
Nominal Size B
Height C
Outside Diameter A
mm
inch
mm
inch
BS EN 1092
ANSI
25
1
58
2.28
PN 6 to 50
150 to 600lb
40
60
2.36
PN 6 to 50
150 to 600lb
50
2
60
2.36
PN 6 to 50
150 to 600lb
65
66
2.60
PN 6 to 50
150 to 600lb
80
3
68
2.68
PN 6 to 50
150 to 600lb
100
4
72
2.83
PN 6 to 50
150 to 600lb
150
6
79
3.11
PN 6 to 50
150 to 600lb
200
8
91
3.58
PN 6 to 50
150 to 600lb
250
10
106
4.17
PN 6 to 50
150 to 600lb
300
12
121
4.76
PN 6 to 50
150 to 600lb
350
14
133
5.24
PN 6 to 50
150 to 600lb
400
16
141
5.55
PN 6 to 50
150 to 600lb
450
18
145
5.71
PN 6 to 50
150 to 600lb
500
20
148
5.83
PN 6 to 50
150 to 600lb

 

Pressure Intelligence

The data shown on these sheets represents the standard offering from Elfab. Depending upon the requirements of your application, Elfab maybe able to provide a solution based on this product but outside the standard operating parameters. In addition, Elfab produces an extensive range of alternative products which maybe more suitable for your requirements.

As a result of extensive testing, Elfab can advise on these choices, or on other technical matters, such as discharge requirements, temperature testing, material selection and corrosion resistance, customised designs and burst detection.

To discuss your specific product or service requirements please contact your Elfab representative.


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