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Torque Procedure

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Additional Info
Number the flange bolts to tighten in the correct pattern
Flange tightening
Flange tightening
Flange tightening

Start the tightening procedure by lubricating the nuts and bolts. Then hand tighten till they are snug against the flanges. If an air wrench is used make sure the pressure is set to the minimum. When tightening, always use the correct sequential bolt order for the flange.

4 and 8 Bolt Flanges

  • First round - 30% of final torque (flange sequential order)
  • Second round- 60% of final torque (flange sequential order)
  • Third round - 100% of final torque (flange sequential order)
  • One final time - clockwise or counter clockwise sequentially around the flange.

12 Bolt Flanges and More

  • First round - 20% of final torque (flange sequential order)
  • Second round - 40% of final torque (flange sequential order)
  • Third round - 80% of final torque (flange sequential order)
  • Fourth round - 100% of final torque (sequential order)
  • One final time - clockwise or counter clockwise sequentially around the flange.

Torque Factor

Pipe Size

(NPS)

150#

(ft-lbs)

300#

(ft-lbs)

400#

(ft-lbs)

600#

(ft-lbs)

900#

(ft-lbs)

1500#

(ft-lbs)

2500#

(ft-lbs)

1/245454545150150
3/445909090150150
145909090240240
1 1/4
1 1/245150150150368368
290909090240240
2 1/290150150150368368
390150150150240533
3 1/2
490150240240533750
51501502403687501200
61501502403685331020
815024036853310201650
1024036853375010203000
1224053375075010203300
14368533750102010204770-
163687501020102016506600-
185337501020165030008800-
2053375012001650330011580-
22-
247501200225030006600-

4 Bolt Tightening Sequence

  • Sequential Order: 1-2, 3-4
  • Rotation Order: 1, 3, 2, 4
4 Bolt Flange

8 Bolt Tightening Sequence

  • Sequential Order: 1-2, 3-4, 5-6, 7-8
  • Rotation Order: 1, 5, 3, 7, 2, 6, 4, 8
8 Bolt Flange

12 Bolt Tightening Sequence

  • Sequential Order: 1-2, 3-4, 5-6, 7-8, 9-10, 11-12
  • Rotation Order: 1, 5, 9, 3, 7, 11, 2, 6, 10, 4, 8, 12
12 Bolt Flange

16 Bolt Tightening Sequence

  • Sequential Order: 1-2, 3-4, 5-6, 7-8, 9-10, 11-12, 13-14, 15-16
  • Rotation Order: 1, 9, 5, 13, 3, 11, 7, 15, 2, 10, 6, 14, 4, 12, 8, 16
16 Bolt Flange

20 Bolt Tightening Sequence

  • Sequential Order: 1-2, 3-4, 5-6, 7-8, 9-10, 11-12, 13-14, 15-16, 17-18, 19-20
  • Rotation Order: 1, 9, 5, 13, 3, 11, 7, 15, 2, 10, 6, 14, 4, 12, 8, 16
20 Bolt Flange

24 Bolt Tightening Sequence

  • Sequential Order: 1-2, 3-4, 5-6, 7-8, 9-10, 11-12, 13-14, 15-16, 17-18, 19-20, 21-22, 23-24
  • Rotation Order: 1, 9, 17, 5, 13, 21, 3, 11, 19, 7, 15, 23, 2, 10, 18, 6, 14, 22, 20, 8, 16, 24
24 Bolt Flange


Data shown on this page was either gathered and verified using data available in the public domain or has been calculated by the staff at Piping-Designer.com. It is up to the end user to verify data prior to use for any project. This page may not be reproduced without the explicit written permission of Piping-Designer.com.
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