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Table 5: Relief Valve Pressure Limits for Pressure-Loaded CVS Type 630R Regulators
Low Pressure Relief
Valve
High Pressure Relief Valve
Loading Regulator Type
Bellofram 7360
Bellowfram 7360
Bellofram P39
Max. Allowable Inlet Pressure to
Relief Valve, PSIG
Relief pressure setting plus maximum
Allowable buildup of 25 psig
Relief pressure setting plus maximum
Allowable buildup of 250 psig
Max. Emergency Inlet (Casing)
Pressure * of Relief Valve, PSIG
75 550
550
Max. Allowable Inlet Pressure to
Loading Regulator, PSIG
75+ 250
550+
Relief Pressure Settings, PSIG
10 to 20 or 20 to 50
50 to 100
100 to 225
Max. Emergency Outlet
(Casing) Pressure * of Loading
Regulator, PSIG
75++ 110
250
* Leakage or bursting of pressure-contained parts may occur if pressure exceeds these values.
+ Limited to this value by maximum emergency inlet pressure of relief valve.
++ Limited to this value by maximum emergency loading pressure of Type 630R
Putting Unit in Service
Use pressure gauges to monitor pressure during
startup.
1. For pressure loaded constructions, turn on
supply pressure to loading regulator.
2. Slowly open upstream shutoff valve.
3. Slowly open the downstream shutoff valve.
4. Check all connections for leaks.
5. If indicated by the monitoring pressure gauges,
make final spring adjustments per the
“Adjustment” section.
Adjustment
The range of allowable pressure settings is marked
on the nameplate. If a pressure setting beyond the
nameplate range is required, substitute an
appropriate spring in the relief valve or loading
regulator. Be sure to change the nameplate to
indicate the new pressure range.
Some pressure ratings are dependent upon the
actual outlet pressure settings being used. For
example, with a Type 630 HP regulator, outlet
pressure must not exceed the setting by more than
20 psig (200 psig for high-pressure constructions), or
damage to internal regulator parts may occur.
However, with some higher-pressure ranges, the
setting plus 20 psig (200 psig for high-pressure
constructions) exceeds the maximum emergency
outlet (casing) pressure. In these cases, outlet
pressure must be limited by the maximum
emergency outlet (casing) pressure. Before
increasing the setting, refer to table 2 through 5 (as
appropriate). Review the pressure limits for the
spring range being used, and be certain that the new
pressure setting will not result in an overpressure
condition. Always use a pressure gauge to monitor
pressure when making adjustments.
Spring Loaded Regulators and Relief
Valves
1. Loosen locknut (Key 22)
2. Rotate the adjusting screw (Key 23) clockwise
to increase the setting or counter clockwise to
decrease the setting.
3. Tighten
locknut.
Pressure Loaded Regulators and Relief
Valves
1. Loosen the locknut found on the loading
regulator adjusting screw.
2. Rotate the loading regulator adjusting screw
clockwise to increase the setting or
counterclockwise to decrease the setting.
3. Tighten
locknut.
Taking out of Service
Isolate the regulator or relief valve from all pressure.
For pressure loaded constructions, shut off supply
pressure to loading regulator.
Cautiously vent all pressure from the regulator or
relief valve before performing any service on the
unit.