MODEL
450-66-Z
BI LEVEL RESERVOIR FLOAT VALVE (with manual selector)
INSTALLATION
OPERATION
MAINTENANCE
The information contained in this document is subject to change without notice.
BERMAD shall not be liable for any errors contained herein. All Rights Reserved. © Copyright by BERMAD Control Valves.
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DESCRIPTION
Model 750-66 Bi-level Reservoir Control Valve is an
automatic control valve designed for two-level
control of the water level in reservoirs and tanks.
Four-way operation enables full opening even at very
low pressure. Full valve opening reduces head loss
to a minimum, prevents abrasion and reduces
cavitation damage. The valve can be operated via an
independent external pressure source when line
pressure is very low, or when the water/liquid is very
dirty or highly corrosive.
INSTALLATION
1. Allow enough room around the valve assembly for
making adjustments and for future maintenance /
disassembly work.
2. Thoroughly flush the pipeline to remove dirt, scale,
and debris. Failure to perform this operation may render
the valve inoperable.
3. Isolation valves A and B should be installed upstream
and downstream of the Bermad control valve to allow
future maintenance operations.
4. Install the valve in the pipeline with the valve flow
arrow on the body casting in the proper direction. Use
the lifting eye provided on the main valve cover for
raising and lowering the valve. For best performance,
install the valve horizontally with the cover up. Ensure
that the valve is positioned so that the actuator assembly
can be easily removed for future maintenance.
5. After installation carefully inspect /correct any
damaged accessories, piping, tubing, or fittings.
ON LINE STATIC TEST PROCEDURES
OPEN VALVE: STATIC TEST
1. Turn cock valve #26 to open position.
Caution:
This will allow the valve to open fully. Make sure that
this condition does not cause system damage.
2. Check for leaks at the flange connection fittings etc.
CLOSED VALVE: STATIC TEST
1. Turn cock valve #26 to close position, vent any trapped air in
the main valve cover by loosening the tube fitting at the highest
point on the cover. This will trap the main valve in a closed
position while the pipeline is pressurized.
2. Check the valve cover and diaphragm area for leaks, tighten
the actuator bolts where necessary.
START-UP OPERATION
1. Close the main valve by closing cock valve #26 and lifting the
float to the upper level.
NOTE
: Isolating valves A and B should be open.
2. Check valve operation by lifting and dropping the float; the
main valve should open and close.
3. If the main valve operating speed increases, fit a needle
valve on either port V on the four-way float pilot or on the
pressure hydraulic tube supply above filter 4. Adjust the needle
valve until the desired flow speed is obtained.
4. Pilot adjustment: Install the pilot valve 66 to the reservoir
wall, higher than the upper level (refer to the drawing). Remove
the plastic float, loosen the counterweight locking screw (9) and
balance the lever system horizontally by moving the
counterweight to find the equilibrium. After balancing, replace
the float and tighten the counterweight locking screw.
5. Adjust the upper/lower water level by moving the float stops
up/down (float while the float is held between the float stops).
6. The float control should be placed where the liquid surface is
free from turbulence; where this is not possible, a stilling tank
must be placed around the float to prevent it from swinging.
7. There should be adequate space between the reservoir wall
and the float.
