Type 99
12
4. Unscrew the diaphragm nut (key 128) and remove
a diaphragm plate (key 41A), diaphragm (key 40)
and another diaphragm plate (key 41B).
5. Unscrew the eight cap screws (key 47) and
remove the pilot body (key 39) and gasket
(key 126). Remove six cap screws (key 35), seal
washers and the flange adaptor (key 125).
6. Unscrew the relief valve body (key 119) and remove
a diaphragm plate (key 41C), diaphragm (key 30)
and another diaphragm plate (key 41D). Inspect the
diaphragm inserts (key 150) and both diaphragms
(keys 30 and 40). Replace if worn or damaged.
7. The relief valve assembly can be further
disassembled for inspection by unscrewing the
relief valve cap (key 118).
8. Four machine screws (key 130) hold both yoke
caps (keys 37 and 116) to the yoke legs (key 31).
Separate these parts to expose the pilot valve.
9. Unscrew the inlet orifice (key 38) to inspect its
seat, the inlet valve plug (key 117) and valve
spring (key 124).
Note
Make certain that the yoke assembly is
square with respect to the cross member
of the body casting so that it will not
bind on the body.
10. When reassembling, screw in the inlet orifice
(key 38) all the way and secure the yoke caps
(keys 37 and 116) to the yoke legs (key 31).
Replace two diaphragm plates (keys 41B and 41D),
the diaphragms (keys 30 and 40) and inserts,
two more diaphragm plates (keys 41A and 41C),
the diaphragm nut (key 128) and the relief
valve assembly.
11. Assemble the control spring (key 43) and spring
seat (key 68) into the body and spring case
(key 44), being careful that the diaphragms
(keys 30 and 40) are free of wrinkles and properly
in place, and evenly installing the cap screws
(key 123) in a crisscross pattern to avoid placing
a strain on the unit. Install the body flange adaptor
(key 125) with seal washers (key 126) and cap
screws (key 47). Install a new gasket and secure
the pilot to the lower casing (key 29) with eight cap
screws (key 47). Set the control spring (key 43)
according to the adjustment information in the
Startup section.
Converting the Pilot
Note
A complete pilot assembly rather than
individual parts may be ordered for
the following conversion procedure.
When a low-pressure pilot is ordered
for field conversion of a high-pressure
pilot or vice versa, the replacement pilot
assembly comes complete with a pilot
cover (key 132, Figure 9). Remove this
cover before installing the replacement
pilot on the existing regulator. The cover
can then be installed on the removed
pilot to form a complete Type 61 (low or
high pressure) pilot for use elsewhere.
When changing one pilot construction (low pressure, high
pressure or extra high pressure) for another, all parts
attached to the lower casing (key 29, Figure 9) may need
to be replaced with those appropriate for the desired
construction. At the very least, when changing from a
low to high-pressure pilot or vice versa, everything below
the lower pilot diaphragm (key 40, Figure 9) except the
cap screws and the hex nut (keys 47 and 13, Figure 9)
will need to be replaced. Actuator and main valve parts
may remain unchanged unless a change in service
conditions requires a change in seat construction, main
spring or main spring seat. See the Parts List sections
for obtaining the appropriate conversion parts.
Main valve Trim with Disk or O-ring Seat
This procedure is to be performed if inspecting, cleaning
or replacing trim parts. Part key numbers for a Type 99
regulator with disk or O-ring seat are referenced in
Figures 9 and 10 and part key numbers for the disk
seat unique to the 1000 psig / 69.0 bar maximum inlet
regulator are referenced in Figure 17.
Note
All trim maintenance may be performed
with the valve body (key 17, Figure 9
or 17) in the line and with the elbow
(key 23), pilot supply tubing (key 24) and
pilot supply regulator (if used) attached
to the valve body unless the valve body
itself will be replaced.
1. Disconnect the pilot supply tubing (key 24) and
downstream control line.