Instruction manual

Type MR105
12
1. Remove the lower indicator tting (key 5)
and attached parts. Proceed to step 5 if only
maintenance on the indicator tting or attached
parts is performed.
2. Loosen the hex nuts (key 29) and stud bolts
(key 3) and remove the body ange (key 2) from
the valve body (key 1).
3. Use the valve body (key 1) as a holding xture
if desired. Flip the body ange (key 2) over and
anchor it on the valve body.
4. To gain access to the port seal (key 12), upper
seal (key 15) or valve plug (key 16) part, unscrew
the seat ring (key 13) from the cage (key 11)
and the cage from the body ange (key 2). To
remove the piston ring (key 14) and/or plug O-ring
(key 20), remove the valve plug (key 16) from
the body ange, insert a screwdriver into the
pre-cut fold over area of the piston ring and unfold
the piston ring. Proceed to step 6 if no further
maintenance is necessary.
5. To replace the body ange (key 2) or gain access
to the valve spring (key 9), indicator stem (key 10),
stem O-ring (key 7), spring seat (key 28) or
E-ring (key 23), remove the indicator protector
(key 19) and indicator scale (key 18). Since some
compression is left in the spring, carefully remove
the anged nut (key 22) and hex nut (key 8). A
screwdriver may be inserted through the O-ring
retainer (key 6) to remove the stem O-ring without
removing the retainer. If necessary, unclip the
E-ring from the indicator stem.
6. Replace and lubricate parts such as the gasket
(key 4) and cage O-ring (key 17) as necessary.
If the port and upper seals (keys 12 and 15)
were removed, install them in their retaining slots
with the grooved sides facing out. Also lubricate
any other surfaces as necessary for ease of
installation. No further main valve maintenance is
necessary if just the lower indicator tting (key 5)
and attached parts were removed.
7. Install the plug O-ring (key 20) and piston ring
(key 14) onto the valve plug (key 16). Insert the
valve plug into the body ange (key 2), install the
cage (key 11) plus upper seal (key 15) and cage
O-ring (key 17) into the body ange and then
install the seat ring (key 13) plus port seal (key 12)
into the cage. Apply a thin coating of lubricant
to seals for protection during assembly. Use the
valve body as a holding xture during this step
and insert a wrench handle (or similar tool) into
the seat ring slots for leverage when tightening the
seat ring and cage.
8. Remove the upside-down body ange (key 2) if
it was anchored on the body (key 1). Coat the
cage seating surfaces of the valve body web
and the body ange seating surfaces of the
valve body neck with a good grade of general-
purpose lubricant.
!
WARNING
Personal injury, equipment damage or

if regulator bolts are not tightened to
proper load. Always tighten bolts in an
alternating pattern.
9. Install the body ange (key 2) on the body (key 1)
and secure it evenly using the stud bolts (key 3)
and nuts (key 29). Tighten to the torque value
specied in Table 6.
10. Make sure that the lower indicator tting and
stem O-rings (keys 21 and 7) and O-ring retainer
(key 6) are installed in the lower indicator tting
(key 5). Install the spring seat (key 28) and attach
it with the E-ring (key 23) to the slotted end of the
indicator stem (key 10). Install the valve spring
(key 9).
11. Being careful not to cut the stem O-ring (key 7)
with the stem threads, install the lower indicator
tting (key 5) down over the indicator stem
(key 10) until resting on the valve spring (key 9).
Install the hex nut (key 8) and then the anged
nut (key 22) on the indicator stem, pushing on the
tting if necessary to provide sufcient stem thread
exposure. To maintain clearance for indicator part
installation, compress the spring seat (key 28) by
turning the hex nut (key 8) down on the stem until
the threads bottom.
12. Install the lower indicator tting (key 5) with
attached parts into the body ange (key 2). Back
off the hex nut (key 8) until the valve spring (key 9)
completely closes the valve plug (key 16) against
the port and upper seals (keys 12 and 15), as
indicated by stem threads showing between the
hex nut (key 8) and indicator tting (key 35). Hold
the indicator scale (key 18) against the indicator
tting with the scale base resting against the
smallest shoulder of the indicator tting and turn
the anged nut (key 22) until its ange is aligned
with the closed scale marking. Then lock both nuts
against each other and install the indicator scale
and protector (keys 18 and 19).