Installation, Operation and Maintenance Manual
Butterfly Valves Type 56, 75, 56D, 75D 13
In case of an abutting thick walled flange and pipe, shave the flange or the pipe inner diameter in order to avoid contact of
pipe and disc. If the inside diameter of the connecting pipe is larger than dimension D below, shaving is not necessary.
Unit: mm (inch)
Nominal size Diameter D
400 (16”) 370 (14.57”)
450 (18”) 422 (16.61”)
500 (20”) 472 (18.58”)
600 (24”) 572 (22.52”)
Torque wrench Spanner wrench Bolt-Nut-Washer (For many flanges specification.)
1) Leave the disc [2] slightly opened by the handle.
Do not make the disc protrude from the seat. (The disc may be damaged.)
2) Set the valve to the coupled flange.
3) Insert the connecting bolt-washer-nuts, and temporarily tighten them by hand.
4) Using a torque wrench, tighten the bolts and nuts gradually to the specified torque in a diagonal manner.
- When you insert a valve between flanges,
please insert after extending the fields of
flanges fully. (If you insert a valve by
force without fully extending fields of
flanges, a liner may be turned over and
suffer a crack.)
- The parallelism and axial misalignment of the flange surface should be under the values shown in the
following table to prevent damage the valve.
(A failure to observe them can cause destruction due to stress application to the pipe)
Unit : mm (inch)
Nom. Size Axial
- Tighten the bolts and nuts gradually with a torque wrench to the specified torque level in a diagonal manner.
(Avoid excessive tightening. (The valve can be damaged.))
Specified torque value Unit Nm {kgfcm} [lbinch]
Nom. Size 400, 450mm (16”, 18”) 500, 600mm (20”, 24”)
Torque value 80 {816} [710] 100 {1020} [887]
(Axial misalignment)
Necessary items
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