11
MR98 Series AD2000 Compliant
D-A-CH Region Only
Table 6.
Number of Diaphragms Required
BODY SIZE
TYPE
SPRING RANGE
DIAPHRAGM MATERIAL
NUMBER OF DIAPHRAGM
NPS 1/2 to 2 /
DN 15 to 50
All
All
Neoprene (CR)
1
Fluorocarbon (FKM)
2
Ethylenepropylene (EPDM)
1
Metal
2
Note
If a metal diaphragm is to be replaced by
an elastomer diaphragm or an elastomer
diaphragm by a metal diaphragm, a new
pusher post is required. Each diaphragm
material requires a different pusher post
length and make sure the proper number
of metal or elastomer diaphragm that will
be used is followed. Refer to the Parts
List section or Table 6 for the correct
number of diaphragm to be used.
9. See Figures 3 to 5. For the metal diaphragms
(key 12), replace the large diaphragm gasket (key 19)
on the surface of the body (key 1) that will support
the diaphragms. There will be two diaphragms
used per regulator. The raised surfaces of the metal
diaphragms should be placed in the unit so that they
are facing toward the assembler (toward the spring)
except only when one diaphragm is being used then
the raised surface should be facing down (towards
the body) (see Figure 2). For elastomer diaphragms,
the printed side should be facing upwards
when installed.
10. Slip the lower spring seat (key 8) and lock washer
(key 28) back onto the pusher post (key 10).
Lubricate the threads of the pusher post and
tighten the pusher post lock nut (key 31) until
the lock washer is flat and then turn the nut an
additional 1/8 to 1/4 turn. Return the diaphragm
(key 12), spring seat and pusher post assembly to
the body (key 1).
Replacement or Maintenance of Bottom
Plug O-ring
If there is any external leakage from the bottom plug,
the bottom plug O-ring could be worn out or damaged.
Proceed as follows to check and/or replace it.
1. Shut down the regulator. Refer to Shutdown
section for the proper procedure.
2. Unscrew the bottom plug (key 5) from the body
(key 1). Inspect the bottom plug seal (key 63)
for damage. Replace the bottom plug seal if
damage is noted. Lightly lubricate the bottom plug
O-ring or graphite ring before installing it onto the
bottom plug.
3. Reassemble the regulator in the reverse order
of the above steps. When installing the bottom
plug (key 5), coat the threads and sealing surface
with anti-seize compound to ensure an adequate
metal-to-metal seal. Reference Table 5 for proper
torque values.
11. Set the relief valve spring (key 11) in the lower
spring seat and place the upper spring seat
(key 9) on the spring.
12. Put the spring case (key 2) over the spring
(key 11) and onto the body (key 1). Tighten the
cap screws (key 16) finger tight only.
13. To ensure proper slack in the diaphragm (key 12),
apply some spring compression by turning the
adjusting screw (key 15) or handwheel (key 38)
clockwise. Finish tightening the cap screws.
See Table 5 for recommended torque values.
