Y690VB Series
4
O-ring. All pressure must be released from the dia-
phragm case before these steps can be performed.
Type Y690VB
Key numbers are referenced in figure 4.
1. Remove the closing cap (key 22) and turn the
adjusting nut (key 20) counterclockwise until all com-
pression is removed from the control spring (key 6). If
the only further maintenance is to change the control
spring (key 6), skip to step 11.
2. Remove the spring case cap screws (key 24) and
hex nuts (key 23, not shown) and lift off the spring case
assembly (key 3).
3. Remove the diaphragm (key 10) and attached parts
by tilting it so that the pusher post (key 8) slips off the
lever assembly (key 16). To separate the diaphragm from
the attached parts, unscrew the diaphragm hex nut
(key 21). If the only further maintenance is to replace
the diaphragm parts, skip to step 8.
4. To replace the lever assembly (key 16), remove the
machine screws (key 17) .
5. To replace the valve stem (key 14) also perform body
area maintenance procedure steps 1 through 4 and pull
the valve stem (key 14) out of the guide insert (key 18).
6. Install the valve stem (key 14) into the guide insert
(key 18) and perform body area maintenance procedure
steps 5 through 7.
7. Install the lever assembly (key 16) into the valve
stem (key 14) and secure the lever assembly (key 16)
with the machine screws (key 17).
8. Reassemble the diaphragm assembly in the
following order:
€ Pusher post (key 8)
€ Diaphragm head gasket (key 45)
€ Diaphragm head (key 7)
€ Diaphragm (key 10)
€ Diaphragm head (key 7)
€ Washer (key 36)
€ Diaphragm nut (key 38)
Secure with 5 to 6 foot-pounds (7 to 8 N•m) of torque.
9. Install the pusher post (key 8) plus attached dia-
phragm parts onto the lever assembly (key 16).
10. Install the spring case assembly (key 3) and
control spring (key 6) on the diaphragm casing (key 4)
so that the vent assembly is correctly oriented, and
secure them with the spring case cap screws (key 24)
and hex nuts (key 23, not shown) to fingertightness
only.
11. Install the upper spring seat (key 19) and the
adjusting nut (key 20) turning clockwise until there is
To avoid personal injury, property damage,
or equipment damage caused by sudden
release of pressure or explosion of accu-
mulated gas, do not attempt any mainte-
nance or disassembly without first isolating
the regulator from system pressure and
relieving all internal pressure from the
equipment.
Body Area
These procedures are for gaining access to the disk
assembly, orifice, and body O-ring. All pressure must
be released from the diaphragm case before the
following steps can be performed.
Key numbers are referenced in figures 3 and 4.
1. To inspect and replace the disk assembly (key 13)
or orifice (key 5), remove the cap screws (key 2), and
separate the diaphragm casing (key 4) from the body
(key 1).
2. Remove and inspect the body seal O-ring (key 11)
and the backup ring (key 50).
3. Inspect and replace the orifice (key 5) if necessary.
Lubricate the threads of the replacement orifice with a
good grade of light grease and tighten using 29
to 37 foot-pounds (39 to 50 N•m) of torque.
4. Remove the cotter pin (key 15) if it is necessary to
replace the disk holder assembly (key 13). For a Type
Y690VBM, also inspect the throat seal O-ring (key 31)
by removing the machine screw (key 33). Replace if
necessary. To install a throat seal, place the O-ring on
the machine screw and thread into guide insert (key 18)
to seal.
Note
The disk holder assembly (key 13) is
comprised of the disk and disk holder.
5. Install the disk holder assembly (key 13) and secure
it to the valve stem (key 14) with the cotter pin
(key 15).
6. Install the backup ring (key 48) and body seal O-ring
(key 11) into the body (key 1).
7. Replace the diaphragm casing (key 4) on the body
(key 1) and secure with the cap screws (key 2).
Diaphragm and Spring Case Area
These procedures are for gaining access to the control
spring, diaphragm assembly, valve stem, and stem
WARNING
!!!!!
