627 Series
10
Refer to Figures 7 through 13 for key number locations.
1. Remove the adjusting screw cap (key 36).
2. Loosen the locknut (key 34).
3. Increase the outlet pressure setting by turning the
adjusting screw (key 35) clockwise. Decrease the
outlet pressure setting by turning the adjusting
screw counterclockwise.
4. When the desired pressure is obtained, hold the
adjusting screw (key 35) in place and tighten the
locknut (key 34).
Shutdown
!
WARNING
To avoid personal injury or property
damage due to explosion or damage to
regulator or downstream components
during shutdown, release downstream
pressure to prevent an overpressure
condition on the diaphragm of
the regulator.
1. Close the nearest upstream shut-off valve.
2. Close the nearest downstream shut-off valve.
3.
Open the vent valve between the regulator and
the downstream shut-off valve nearest to it.
4. For a Type 627, 627H, 627R, or 627LR regulator,
the regulator will open to release pressure between
the upstream shut-off valve and the regulator.
5. A Type 627M, 627HM, or 627MR regulator requires
venting the control line and downstream pressure
from the regulator before maintenance. The
pressure between these shut-off valves is released
through the open regulator because the disk
assembly remains open in response to the decrease
in control line pressure.
Maintenance
Unless otherwise specified, the following maintenance
procedures apply to all types of regulators. For a
summary of maximum torque values required for all
types of regulators, refer to Table 7.
Due to normal wear, damage from external sources,
or debris in the air or gas line, regulator parts such
as the disk assembly, orifice, and diaphragm must
Figure 4. Relief Indicator
W4665
RELIEF
INDICAToR
CAP (KEy 49)
be inspected periodically and replaced as necessary
to ensure correct performance. The frequency of
inspection and replacement depends upon the severity
of conditions and the requirements of state and federal
laws. Normal wear of the orifice and disk assembly is
accelerated with high pressure drops and with large
amounts of impurities in the flowstream. Instructions
are given below for replacing the disk assembly,
orifice, diaphragm, and O-rings. These procedures
may also be used for disassembly required for
inspection and replacement of other parts.
Problem Indication for Types 627R,
627LR, and 627MR Regulators
!
WARNING
Isolate the regulator from all pressure
to avoid personal injury and equipment
damage due to explosion or sudden
release of process pressure. Cautiously
release pressure from the regulator
before attempting disassembly.
The vent assembly is equipped with a relief indicator
(key 49, Figure 4). The cap for the relief indicator
snaps over the vent assembly opening. If the
relief valve opens wide, exhaust gas pops the cap
off the screen vent assembly opening indicating a
problem with the regulator. If the cap pops off, refer
to the shutdown and to the Body Area Maintenance
Procedures to inspect the disk assembly and orifice.
If the disk assembly and orifice are not damaged, refer
to the Diaphragm and Spring Case Area Maintenance
Procedures in this section.