This document is a technical guide from Flexitallic US, LLC, detailing the torque specifications for Spiral Wound Gaskets classified under various pressure classes. It provides a comprehensive chart listing minimum and maximum torque values for different sizes and classes, including Class 150, Class 300, Class 400, and more. The document emphasizes the importance of using Alloy Steel Bolts with specific lubrication for accurate torque application. It also includes notes on the limitations of torque values based on operating conditions and stresses the need for caution in extreme applications. This PDF serves as a valuable resource for engineers and professionals in the field of gasket installation and maintenance, ensuring proper sealing and safety in high-pressure environments.
Min Torque Max Torque Min Torque Max Torque Min Torque Max Torque Min Torque Max Torque
0.5
30 50 30 40 30 40 30 40
0.75
30 50 60 80 60 80 60 80
1
30 60 60 80 60 80 60 80
1.25
30 60 60 80 60 80 60 80
1.5
30 60 100 140 100 140 100 140
2
60 120 60 80 60 80 60 80
2.5
60 120 100 140 100 140 100 140
3
90 120 100 150 100 150 100 150
3.5
60 120 100 170 160 290 170 290
4
70 120 100 200 160 320 190 320
5
100 200 110 200 210 320 280 490
6
130 200 110 200 190 320 260 460
8
180 200 180 320 310 490 400 700
10
170 320 250 460 360 710 500 800
12
240 320 360 700 510 1000 500 850
14
300 490 360 610 500 870 680 950
16
310 490 500 920 680 1250 800 1210
18
490 710 500 1000 680 1340 1100 1790
20
430 710 500 1000 800 1430 1100 1640
24
620 1000 800 1600 1500 2270 2000 2670
Min Tor
q
ue Max Tor
q
ue Min Tor
q
ue Max Tor
q
ue Min Tor
q
ue Max Tor
q
ue
Spiral Wound Gasket CGI
Class 600Class 400Class 300Class 150
NPS (in.)
Class 2500Class 1500Class 900
NPS
q
q
q
q
q
q
0.5
70 120 70 120 50 100
0.75
70 120 70 120 63 100
1
110 190 110 190 110 160
1.25
110 190 140 190 210 250
1.5
170 290 200 290 310 360
2
110 190 130 190 220 250
2.5
170 290 190 290 300 360
3
140 230 270 360 460 500
4
260 420 420 520 710 800
5
360 600 590 800 1280 1500
6
300 500 530 680 1870 2200
8
485 800 850 1100 1780 2200
10
505 800 1570 2000 3040 4400
12
560 850 1500 2200 4610 5920
14
630 940 2120 3180
16
910 1290 2940 4400
18
1570 2340 3950 5920
20
1745 2570 5150 7720
24
2945 5140 8340 12500
Notes:
Torque Values are in ft.-lbs., and assume Alloy Steel Bolts (A193 B7 w/ 2H Nuts) with oil/graphite lubrication.
This Document is the property of Flexitallic US, LLC and is not to be reproduced, transmitted to another, nor used for the purpose of manufacturing of
articles for sale to anyone but Flexitallic US, LLC without Flexitallic's specific written permission.
Flexitallic does not accept responsibility for the misuse of this information.
Torque values limit minimum and maximum gasket seating stresses based upon pressure class and certain operating conditions.(i.e: maximum pressure
ratings for given pressure class,not hydrotest pressure), Extreme operating conditions such as high temperature may reduce bolt yield strength. Caution
should be used in these applications. The above torque values are for general use only. For critical or extreme applications (high temperature/pressure)
consult with Flexitallic engineering.
(Nut factors used on these charts are within .15 to .19)
Flexitallic does not generally recommend a bolt stress above 60,000 PSI
06/19
End of Document
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