limit of the control pressure range or
that particular spring (see Specifications
section). if the desired control pressure
is not within the range of the control
spring, install a spring of the proper
range according to the Diaphragm
and Spring case area section of the
Maintenance procedure.
With installation completed, the regulator can be
placed in operation by slowly opening the upstream
and downstream block valves, if used, while using
gauges to monitor pressure. The regulator takes
control when downstream pressure is established.
The regulator has been adjusted at the factory to
provide approximately the control pressure requested.
To ensure the correct pressure setting always use a
pressure gauge to verify the pressure setting. The
range of allowable pressure settings is stamped on the
spring casing nameplate. If a pressure setting beyond
the stamped range is required, install a spring with the
desired range by following the procedures for changing
the spring and diaphragm in the Maintenance section.
To adjust the pressure setting, perform the following
steps (key numbers are referenced in Figure 6):
1. Remove the closing cap (key 3, if required).
2. Turn the adjusting screw (key 2) either clockwise
to increase control pressure or counterclockwise
to decrease control pressure. The regulator will
go into immediate operation. To ensure correct
operation always use a pressure gauge to monitor
the blanket pressure when making adjustments.
3. Replace the closing cap (key 3, if required).
Shutdown
Installation arrangements vary, but in any installation
it is important to open and close valves slowly and
to close the upstream block valve first when shutting
down the system.
First, close the nearest upstream block valve and
then, close the nearest downstream block valve to
vent the regulator properly. Next, open the vent valve
between the regulator and the downstream block valve
nearest to it. Then, open the upstream vent valve and
the vent valve in the control line. All pressure between
these block valves is released through the open vent
valves, since a gas blanketing regulator remains open
in response to the decreasing downstream pressure.
If vent valves are not installed, safely bleed off both
inlet and outlet pressures and check that the regulator
contains no pressure.
Maintenance
Regulator parts are subject to normal wear and
must be inspected and replaced as necessary. The
frequency of inspection and replacement of parts
depends upon the severity of service conditions
or the requirements of local, state and federal
regulations. Due to care Emerson takes in meeting
all manufacturing requirements (heat treating,
dimensional tolerances, etc.), use only replacement
parts manufactured or furnished by Emerson.
!
WaRninG
To avoid personal injury, property damage
or equipment damage caused by sudden
release of pressure, isolate the regulator
from all pressure and cautiously release
trapped pressure from the regulator
before attempting disassembly.
Key numbers are referenced in Figure 6.
Body area
This procedure is for gaining access to the disk
assembly, orifice, body gasket, split ring and pitot tube if
used. All pressure must be released from the regulator,
before these steps can be performed.
1. Unscrew the union nut (key 19) from the body
(key 28) and remove the lower casing assembly
(key 20) and split ring (key 17). The lower casing
assembly (key 20) must be tipped toward the
body outlet to allow removal clearance for the
pitot tube (key 74).
2. Inspect and replace the orifice (key 27)
if necessary. Lubricate the threads of the
replacement orifice with a good grade of pipe
thread sealant. Install the orifice with 75 to
100 ft-lbs / 102 to 136 N•m of torque.
3. Remove the cotter pin (key 14) if it is necessary to
replace the disk assembly (key 25).
4. To replace the pitot tube (key 74) on units with
internal pressure registration, remove the flared
end connection and press a new pitot tube into
the pitot tube hole and secure by flaring the end.
Rotate the pitot tube so that it points into the
outlet of the body (key 28) after the lower casing
assembly (key 20) is installed.
5
Type Y692
