ASME Bolt Torque Values

Bolt Torque Values for ASME B16.5 Series A Class 150# Flat Flanges
with A193 Grade B7 Bolts

For Full Face Homogenous Elastomeric Gaskets

        <70 durometer Shore A >70 durometer Shore A
Nominal Pipe Size (in) # of Bolt Holes (in) Size of Bolts (in) Minimum Torque (ft. lbs.) Preferred Torque (ft. lbs.) Preferred Torque (ft. lbs.)
0.50 4 0.50 9 14 19
0.75 4 0.50 12 17 23
1.00 4 0.50 14 21 28
1.25 4 0.50 16 24 32
1.50 4 0.50 19 28 37
2.00 4 0.63 33 49 66
2.50 4 0.63 45 67 90
3.00 4 0.63 49 73 97
3.50 8 0.63 30 45 60
4.00 8 0.63 33 49 66
5.00 8 0.75 41 61 82
6.00 8 0.75 46 69 92
8.00 8 0.75 66 99 132
10.0 12 0.88 64 96 128
12.0 12 0.88 93 140 186
14.0 12 1.00 134 201 268
16.0 16 1.00 120 181 241
18.0 16 1.13 132 198 264
20.0 20 1.13 124 187 249
24.0 20 1.25 173 260 347

Bolt Torque Values for ASME B16.47 Series A Class 150# Flat Flanges
with A193 Grade B7 Bolts

For Full Face Homogenous Elastomeric Gaskets

        <70 durometer Shore A >70 durometer Shore A
Nominal Pipe Size (in) # of Bolt Holes (in) Size of Bolts (in) Minimum Torque (ft. lbs.) Preferred Torque (ft. lbs.) Preferred Torque (ft. lbs.)
26 24 1.25 238 238 318
28 28 1.25 224 224 299
30 28 1.25 248 248 331
32 28 1.50 309 309 412
34 32 1.50 283 283 377
36 32 1.50 309 309 411
38 32 1.50 356 356 474
40 36 1.50 328 328 438
42 36 1.50 354 354 472
44 40 1.50 339 339 452
46 40 1.50 354 354 473
48 44 1.50 342 342 456
50 44 1.75 470 470 626
52 44 1.75 502 502 669
54 44 1.75 535 535 713
56 48 1.75 528 528 705
58 48 1.75 561 561 747
60 52 1.75 530 530

707

TORQUE
After installing a new gasket or seal it’s essential to tighten the fasteners with a torque wrench that’s been recently calibrated. Without this it’s impossible to know if the joint has been tightened to the required level. Friction between the nut, washers, flange faces and thread increases the torque measured at the wrench, possibly resulting in insufficient clamping force being applied to the gasket. Avoid this by applying a thin, uniform coating of high quality lubricant to the underside of bolt heads, nuts and washers and the thread itself. Take care to keep it off the gasket.