IM-S24-15 CH Issue 4
18
4.5 Replacing a PTFE soft seal (DN150 and DN200 valves)
When replacing a soft seal plug / assembly, proceed as follows:
- Taking care not to damage the stem, post or head remove the 6 bolts which attach the
retaining cover (A) to the valve head (B) and remove the old PTFE seal.
- Clean all mating surfaces and fit the new PTFE seal (C). Refit the retaining cover (A), by
assembling the 6 bolts (D) and tightening to a torque of 40 N m (30 lbf ft). The threaded
holes in the valve head have locking wire thread inserts which provide a locking function
for the bolts.
- Reassemble the plug / stem assembly, then reassemble the valve using a new bonnet
gasket.
- Bring the valve back into service.
- Check for any leakage at the gland.
D
A
C
B
Fig. 5
To Next Page
Loading...
