Samson 3321CT, Mounting And Operating Instructions

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EB 8115 EN 15-1
Annex
15 Annex
15.1 Tightening torques
Note concerning the following specifications:
− All tightening torques specified in Nm
− Tightening torque tolerance: ±10 %
− The tightening torques are based on a friction coefficient of 0.06 with a lubricated seat
thread and facing.
− After long operating times or long periods or use at temperatures above 250 °C, the
breakaway torque may be twice as high as the tightening torque.
15.1.1 Tightening torques to install the seat
Valve size Seats (2) made of 1.4404
DN NPS Thread Without torque multiplier With torque multiplier 1)
15 to 25 ½ to 1 M32x1.5 160 – 2)
32 to 50 1½ to 2 M58x1.5 480 38
65 to 80 2½ to 3 M90x1.5 900 72
1)
Torque multiplier with gear ratio 1:12.5
2)
Only use a torque wrench to tighten the seat; do not use an additional torque multiplier.
15.1.2 Tightening torques for connection of body and bonnet
Valve size
Tightening torque for body nut (10)
DN NPS
15 to 25 ½ to 1 30
32 to 50 1½ to 2 50
65 to 80 2½ to 3 100