Spirax Sarco 37D, Installation And Maintenance Instructions Manual

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IM-P102-04 CTLS Issue 7
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Table 2 Recommended tightening torques for main seat
Size of valve Width across flats Tightening torque
½", ½" LC, DN15 & DN15LC 30 mm (1.18") (external) 110 - 120 N m (81 - 89 lbf ft)
¾" & DN20 36 mm (1.42") (external) 140 - 150 N m (103 - 111 lbf ft)
1" & DN25 19 mm (0.75") (inside) 170 - 180 N m (125 - 133 lbf ft)
DN32 24 mm (0.94") (inside) 200 - 210 N m (148 - 155 lbf ft)
DN40 30 mm (1.18") (inside) 230 - 240 N m (170 - 177 lbf ft)
DN50 41 mm (1.61") (inside) 270 - 280 N m (199 - 207 lbf ft)
41. Undo the long nuts and pull away.
42. Undo the M12 nuts and bolts.
43.
Drop away the lower diaphragm chamber, the two diaphragms, diaphragm plate and the push rod
assembly.
44. Refit the push rod assembly.
45.
Refit the main valve head, make sure the valve locates on seat.
46. Open the valve by pushing onto the diaphragm plate until it comes up against the stop of the body.
47. Check the valve lift (shown in Table 3) using a depth gauge.
Table 3 Valve lift
Size of valve DN15LC DN15 DN20 DN25 DN32 DN40 DN50
Lift
2.0 mm
(0.08")
2.0 mm
(0.08")
2.5 mm
(0.10")
3.0 mm
(0.12")
3.5 mm
(0.14")
4.5 mm
(0.18")
5.0 mm (0.20")
Adjust if necessary by screwing push rod in or out of diaphragm plate.
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