Water Distribution And Heat Transfer Section; Water Level Control - BAC PT2 Operation & Maintenance Manual

Figure 6. Nozzle Spray Pattern
DANGER: Rotating equipment
will cause severe personal injury
or death to persons who come in
contact. Do not perform any service,
maintenance or inspection on or
near the fans, motors, and drives,
or inside the unit without first
ensuring that the fan and pump
motors are disconnected, locked
out, and tagged out.
CAUTION: Drift eliminators are not
designed to support the weight of a
person or to be used as a storage or
work surface for any equipment or
tools. Misuse can result in physical
injury and/or equipment damage.
NOTICE: Do not use steam or
high pressure water to clean PVC
eliminators, fill or materials other
than steel.
NOTE: If the unit has been ordered
with the optional electric water
level control package or is intended
for remote sump application, a
mechanical water make-up valve
will not be provided.
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Water Distribution System and Heat Transfer Section
The hot water is distributed through a corrosion resistant polyvinyl chloride (PVC) spray
distribution system. The fill and drift eliminators are also made of PVC, which requires no
protection against rot, decay, rust, or biological attack.
The inspection procedure is as follows:
• Shut off the fan and system pump. Lock out and tag out the fan and pump motors.
• Remove drift eliminators to allow a clear view of the spray distribution system and
nozzle patterns.
• Start the system pump. Make sure the fan motor is locked out and tagged out. Check
to see if the nozzles are all spraying consistently and producing the spray pattern
shown in Figure 6.
• Quarterly or more often as required, turn off the fan and pump, and flush any dirt
or debris from the water distribution system to prevent clogged nozzles. Clean any
nozzles that are clogged. If necessary, the nozzle and rubber grommet may be
removed for cleaning. To remove, grasp the nozzle and pull while twisting. Replace any
damaged nozzles. If additional cleaning is necessary the branch may be removed for
cleaning. With the BranchLok™ System, tools are not required to remove eliminator
support channels or branches.
With electrical heater tape, heat trace and insulate all exposed water piping, including
pump piping below the overflow level and make-up water lines.

Water Level Control

There are two types of water level controls used on BAC Cooling Towers:
• Mechanical make-up valve assembly
• Optional electric water level control package
Mechanical Make-up Valve Assembly
A float-operated mechanical water make-up assembly is furnished as standard equipment
on the unit. The standard make-up assembly consists of a corrosion resistant make-up
valve connected to a float arm assembly actuated by a polystyrene-filled plastic float. The
float is mounted on an all-thread rod held in place by wing nuts. The cold water basin
operating water level can be adjusted by repositioning the float and all-thread rod using
the wing nuts provided.
• Inspect the make-up valve assembly monthly and adjust if necessary.
• Inspect the valve annually for leakage. Replace the valve seat if necessary.
• Maintain the make-up water supply pressure between 15 psig and 50 psig for proper
operation. BAC recommends a pressure regulator valve (provided by others) for
pressures over 50 psig.
• Set the initial basin water level by adjusting the wing nuts so that the make-up valve is
completely closed when the water level in the cold water basin is at the operating level
as stated in Table 1 on page 10.