NIBCO Flanged End Outside Screw and Yoke Cast and Ductile Iron Globe and Angle Valves - Manual (Page 9)

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4. Clean off the gasket. Make sure that no foreign particles are stuck to it that might cause
a leak. Make sure the gasket is the correct size. It should fit inside the bonnet-body bolt
holes.
5. Place the bonnet in position; insert the bolts and hand tighten the nuts against the body.
A minimum of 2-1/2 threads should extend beyond each nut.
6. After the nuts are hand tight, follow the tightening sequence shown in the table. The
sequence shown is an illustrated method only, and the actual sequence is dependent
upon the total number of bolts.
7. The use of an air impact device which does not have a direct torque control is prohibited
for the torquing of body-to-bonnet bolts. The use of a hand torque wrench, electronic
torquing system, or power wrench with direct torque control is recommended. If such
equipment is not available, the following standard wrenches may be used:
1/2” bolts 6” wrench
5/8” bolts 12” wrench
3/4” bolts 18” wrench
7/8” bolts 24” wrench
1” bolts 36” wrench
IRON VALVE BOLT TORQUE
Before tightening, make sure all surfaces that the fastener will contact are clean and dry.
The torque tightening table listed below applies to clean, undamaged, non-lubricated threaded
fasteners (lubricated threaded fasteners may require less torque – consult the fastener
manufacturer for more detailed instructions).
When tightening, use the sequence chart below. Tighten in two steps.
1. Tighten fastener using about 1/2 the final torque figure.
2. Final tightening using the full torque figure. ASTM A307 steel only.
Fastener Size 7/16 1/2 9/16 5/8 3/4 7/8 1 1-1/8 1-1/4 1-3/8 1-1/2
Torque in Ft. Lbs. 30 45 66 93 150 202 300 474 659 884 1057