Spirax Sarco DP27, Installation And Maintenance Instructions Manual

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IM-P470-03 CH Issue 7
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37. DP27, DP27E and DP27Y
Remove the pilot valve housing, complete with spring housing assembly.
DP27R
Remove the pilot valve housing, complete with air control block.
38. Remove the main valve plus internal strainer screen and clean.
39.
Remove the main valve spring and the main valve head. Clean to remove dirt or scale
as necessary.
40. Remove the main valve seat. Clean and remove dirt and scale as necessary.
Note: Examine the faces of the main valve head and seat. If they are only slightly worn
they may be lapped on a flat plate using a fine grinding paste. If either is badly worn or
unfit for further use they must be replaced.
41. Refit the valve seat applying jointing compound to the seating faces and tighten to the
recommended torque shown in Table 2, opposite.
Where a new part has been fitted it will be necessary to reset the main valve pushrod to
give the correct valve lift.
To do this it is necessary to expose the main diaphragm plate and pushrod assembly.
42.
Undo the long nuts and pull away.
43. Undo the M12 nuts and bolts.
44. Drop away the lower diaphragm chamber,
the two diaphragms, diaphragm plate and
pushrod assembly.
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