Y690VB Series
5
enough control spring (key 6) force to provide proper
slack to the diaphragm (key 10) and attached parts.
Using a crisscross pattern, finish tightening the spring
case cap screws (key 24) and hex nuts (key 23) to 160
to 190 inch-pounds (18 to 21 N•m) of torque. Then finish
turning the adjusting nut to the desired outlet pressure
setting.
12. Install a replacement closing cap gasket (key 25)
if necessary, and then install the closing cap (key 22).
Type Y690VBM
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, 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
(key 10) from the attached parts, unscrew the dia-
phragm hex nut (key 21). If the only further mainte-
nance 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) or stem seal O-
ring (key 30) perform body area maintenance procedure
steps 1 through 4 and pull the valve stem out of the
guide insert (key 18).
6. Lightly grease the replacement stem seal O-ring
(key 30) and install on the valve stem (key 14). Install
the valve stem by pushing it 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 (key 26) 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 adjusting
nut (key 20). Turn adjusting nut clockwise until there is
enough control spring (key 6) force to provide proper
slack to the diaphragm (key 10) and attached parts.
Using a crisscross pattern, finish tightening the spring
case cap screws (key 24) and hex nuts (key 23, not
shown) to 160 to 190 inch-pounds (18 to 21 N•m) of
torque. Then finish turning the adjusting nut to the
desired outlet pressure setting.
12. Install a replacement closing cap gasket (key 25)
if necessary, and then install the closing cap (key 22).
To Convert Constructions
The Type Y690VB to the Type Y690VBM:
New parts required: keys 30, 31, and 33
1. Remove pipe plug (key 27) from the diaphragm casing
(key 4).
2. Refer to steps 1 and 3 in the Body area maintenance
section.
3. Insert the throat seal O-ring (key 31, figure 3) and one
machine screw (key 33).
4. Insert the stem seal O-ring (key 30) by following
steps 1 through 7 and 9 through 12 in the Diaphragm and
Spring Case Area Maintenance Section
The Type Y690VBM to the Type Y690VB:
New parts required: key 27
1. Insert pipe plug (key 27) in the diaphragm casing
(key 4).
2. Follow steps 1 through 7 and 9 through 12 in the
Diaphragm and Spring Case Area Maintenance Section
to remove the stem seal O-ring (key 30, figure 3).
Follow steps 1 through 7 of Body Area Maintenance to
remove the throat seal (key 31) and machine screw
(key 33).
Parts Ordering
When corresponding with the Fisher Sales Office or
Sales Representative about this regulator, include the
type number and all other pertinent information
stamped on the nameplate (key 46). Specify the eleven-
character part number when ordering new parts from
the following parts list.
