Emerson Fisher 161AY Series Instruction Manual page 17

PROBLEM
Outlet pressure suddenly rises above
setpoint and approaches inlet pressure
Outlet pressure normal at low flow but
falls below setpoint at high flow
Outlet pressure cycles
Gas escapes from pilot spring case
Gas escapes from travel indicator
Regulator unexpectedly closes or falls
below setpoint
Outlet pressure approaches inlet
pressure when no flow is desired
Regulator will not open
Regulator will not close
High lock-up pressure with slow shutdown
High lock-up pressure with fast shutdown
Note: If you were unable to solve your problem using this troubleshooting guide, contact your local Sales Office.
if flow is not in the correct direction. After
assembly, check the regulator for shutoff
and leakage to atmosphere.
Disassembly
Disassembly of Type EZR
1. Shutdown, isolate and depressurize the main
valve and pilot.
2. Remove travel indicator assembly or travel
indicator plug assembly using the Travel Indicator
Assembly Maintenance section.
3. Remove the cap screws (key 3). Lift up and
remove the bonnet (key 2) from the body (key 1).
For the NPS 8 / DN 200 body, the
lifting flange (key 143) is capable
of supporting the full weight of the
regulator assembly and can be utilized
to lift bonnet if required.
4. Remove the diaphragm and plug assembly (key 9)
and bonnet O-ring (key 28). For NPS 2 x 1 /
DN 50 x 25 sizes, use a screwdriver to remove the
upper adaptor (key 131).
Table 12. Troubleshooting Guide
• If travel indicator is in UP position, check restrictor and pilot supply filter for plugging
• If travel indicator is in DOWN position, check main valve for debris or diaphragm damage
• Check main valve inlet strainer for plugging
• Check inlet pressure at high flow condition
• Check sizing calculations to be sure main valve body is large enough for load
• Check for undersized or restricted control line (use the minimum size given in step 6 of All Installations of the
Type EZR Installation section).
• Adjust restrictor to a lower setting
• Adjust restrictor to a higher setting
• Check control line placement. Make sure it is not located in a turbulent area.
• Make sure there is not a restriction in the control line, such as a needle valve.
• Replace pilot diaphragm assembly
• Replace indicator stem O-ring, if indicator is not desired, convert to a non-travel indicator assembly
• Check pilot for ice. Moisture in the gas can cause ice to form and build up in the pilot, blocking the flow.
Heating the regulator or adding a de-icing agent will reduce the possibility of icing.
• Check main valve O-rings for damage or improper installation
• Check cage and diaphragm surfaces for erosion or trapped debris
• Check pilot valve plug and seat for seating surface damage or debris
• Check pilot for ice
• Check for clogged control line
• Make sure control line is installed and open
• Check for damage to the main valve diaphragm
• On new installations, make sure the control line and pilot supply are properly connected
• Make sure the pilot supply is properly connected
• Check restrictor for clogging
• Check the main valve diaphragm for damage
• Check for a broken control line
• Check for debris on main valve or pilot seat
• Adjust restrictor to a higher setting
Note
POSSIBLE SOLUTION
5. Pull out the cage (key 7), O-ring (key 8) and inlet
strainer or strainer shim (key 23) (if no strainer).
For NPS 2 x 1 / DN 50 x 25 sizes, remove the
lower adaptor (key 132).
6. Clean parts and replace if necessary. To change
the O-ring (key 121) on a 6 in. / 152 mm cage with
attached restrictor plate (key 71), remove cap screws
(key 126).
Assembly
1. Install the inlet strainer or shim (key 23) into the
body (key 1).
When installing in a vertical orientation,
apply lubricant to the bottom of the inlet
strainer or strainer shim (key 23) to help
hold parts in place while installing cage.
2. Lightly lubricate and install the cage O-ring (key 8).
3. Apply lubricant lightly to all O-rings or the mating
part before installing them.
4. Install the cage (key 7) and lightly lubricate and
install the bonnet O-ring (key 28).
Type EZR
Note
17