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Cla-Val 50B-4KG1/2050B-4KG1 Quick Manual User Manual

Pressure relief valve, Model installation / operation / maintenance

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The Cla-Val Model 50B-4KG1 Globe /2050B-4KG1 Angle
Pressure Relief Valve is designed specifically to automatically
relieve excess pressure in fire protection pumping systems. Pilot
controlled, it maintains constant system pressure at the pump dis-
charge within very close limits as demands change.
The Fire Pump Pressure Relief Valve shall modulate to relieve
excess pressure in a fire protection system. It shall maintain con-
stant pressure in the system regardless of demand changes. It
shall be pilot controlled and back pressure shall not affect its set
point. It shall be actuated by line pressure through a pilot control
system and open fast in order to maintain steady system pressure
as system demand decreases. It shall close gradually to control
surges and shall re-seat drip-tight within 5% of its pressure setting.

INSTALLATION
1.

Allow sufficient room around the valve assembly to make

adjustments and for servicing.
2.

lt is recommended that gate or block valves be installed to

facilitate isolating valve for preventative maintenance. When used
as a surge control or pressure relief valve where valve outlet dis-
charge is to atmosphere, then a gate or block valve is needed at
valve inlet. When used as a back pressure sustaining control
valve where valve outlet is connected to pressurized downstream
system, then gate or block valves are needed at valve inlet and
outlet.
NOTE: BEFORE THE VALVE IS INSTALLED, PIPE LINES
SHOULD BE FLUSHED OF ALL FOREIGN MATTER.
3.

Place valve in line with flow through valve in direction indicated

on inlet plate or flow arrows. Check all fittings and hardware for
proper makeup and verify that no apparent damage is evident.
4.

Cla-Val Valves operate with maximum efficiency when mounted

in horizontal piping with the cover UP; however, other positions are
acceptable. Due to size and weight of cover and internal components
on six inch and larger valves, installation with the cover up is
advisable. This makes periodic inspection of internal parts readily
accessible.

5.

Caution must be taken in the installation of this valve to insure that

galvanic and/or electrolytic action does not take place. The proper use
of dielectric fittings and gaskets are required in all systems using dis-
similar metals.

OPERATION AND START-UP
1.

Prior to pressurizing the valve assembly make sure the nec-

essary gauges to measure pressure in the system, are installed
as required by the system engineer.
CAUTION:

During start-up and test a large volume of water

may be discharged downstream. Check that the downstream
venting is adequate to prevent damage to personnel and equip-
ment. All pilot adjustments should be made slowly in small
increments.

If the main valve closes too rapidly it may cause

surging in upstream piping.
2. Remove cap from CRL-60 then loosen adjusting screw coun-
terclockwise. This will allow the valve to open at low pressure
relieving the full flow of the fire pump. Bleed all air from the valve
at this time by carefully loosening the cover plug and tube fittings
at the high points. Slowly turn the adjusting screw clockwise on
the CRL-60 while watching the gauge between the valve and the
pump until you reach the desired set-point. Tighten the jam nut on
the CRL-60 and replace the cap. DO NOT USE THE GAUGE
PROVIDED ON THE VALVE TO SET THE VALVE. IT IS ONLY
THERE TO INDICATE PRESSURE IN THE COVER.

MAINTENANCE
1.

Cla-Val Valves and Controls require no lubrication or packing

and a minimum of maintenance. However, a periodic inspection
schedule should be established to determine how the fluid is
affecting the efficiency of the valve assembly. Minimum of once
per year.
2.

Repair and maintenance procedures of the Hytrol Main Valve

and control components are included in a more detailed Tech
Manual. It can be downloaded from our web site (www.cla-val.com)
or obtained by contacting a Cla-Val Regional Sales Office.
3. When ordering parts always refer to the catalog number
and stock number on the valve nameplate.

Pressure Relief Valve

50B-4KG1/2050B-4KG1

MODEL

INSTALLATION / OPERATION / MAINTENANCE

SYMPTOM

PROBABLE CAUSE

REMEDY

Main valve
won’t open

Inlet pressure is below set-
ting of pilot valve.

Reset pilot valve. If
change is from tam-
pering, seal cap with
wire and lead seal.

Pilot valve is stuck closed:
Mineral deposit or foreign
material between disc retain-
er and stem guide.

Disassemble control
and clean.

Water is com-
ing out of vent
hole in cover

Pilot valve diaphragm is rup-
tured or diaphragm nut is
loose.

Disassemble and
replace diaphragm.
Tighten nut.

Main valve is
stuck closed

Mineral build-up on stem.
Stem damaged.

Disassemble main
valve, clean parts
and/or replace
damaged part.

Main valve
won’t close

Inlet pressure is above set-
ting of pilot valve.

Reset pilot valve

Clogged orifice or strainer.

Disassemble and
clean.

Pilot valve is stuck open:
Foreign material or mineral
deposit under disc retainer or
diaphragm assembly.

Disassemble and
clean.

Main valve
stuck open

Foreign material or mineral
deposit between seat and
disc assembly.

Disassemble and
clean.

Main valve diaphragm worn
out.

Disassemble and
replace.

Valve leaks
continuously

Pilot valve disc worn out.
Main valve disc worn or dam-
aged.

Disassemble and
replace.

Set point too close to inlet
pressure.

Reset pilot valve.