Honeywell HON 512 User And Maintenance Manual page 129

HON 512 with HON 650 pilot user manual
Figure Step Description
18 Align the valve body as shown.
Insert the assembly aid, with the milled
surface facing upward towards the piston
opening, into the valve body.
19 Replace the diaphragm (2) and the stem
seal with new ones.
Install the diaphragm, including the stem
seal and the diaphragm plate (1), on the
connecting piece.
Make sure that the diaphragm is aligned
correctly: The side of the diaphragm that
has a depression at the center should be
facing upward.
20 Replace the piston with a new one. Insert
the new piston into the connecting piece.
Risk of confusion! Please observe the
characterizing difference between the old
and the new piston:
▪ Old piston (1):
Castellated nut closed
▪ New piston (2):
Castellated nut open
21 Lightly coat the thread surfaces with
threadlocker.
Put the cap (1) in place.
Tighten the cap (1) while using an
open-end wrench to hold the diaphragm
plate (2) in place so as to prevent the
components from turning.
Observe the tightening torque information
provided in the table before this section.
22 Remove the assembly aid (2) from the
valve body.
Screw the assembly aid (2) into the new
valve insert (1).
Maintenance
129