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Accessories
Tank
Liners and Coatings
Ventilation
Systems
Heating
and Insulating
Heat
Exchangers
Level
Transmitters / Indicators
Scales
and Load Cells
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Level
Sensors, Controllers, and Indicators
C.R.T.
offers a number of different options when
it comes to controlling and inventorying
the amount of liquid in your tank. Prices
can range from $100 per tank to well over
$5000 per tank, depending on the style,
wetted surface, tank size and display
that you require.
- Magnetic
Float Switch. This type of unit
is often used in O.E.M. applications where
an inexpensive level indicator is needed
to control a pump, an alarm, a valve,
a mixer or some type of single control.
Each unit can easily be mounted at the
desired depth in a tank through a tank
inlet and wired to a control panel. Prices
will greatly vary on material of construction.
Advantage: Price. Disadvantage:
only one signal per unit, mechanical movement
of float can be faulted by flow, viscosity,
stickiness, or temperature.
- Multiple
Magnetic Float Switch. This unit
extends down in to the depths of the tank
and uses multiple magnetic switches inside
the length of the float stem. It can indicate
numerous levels at which pumps, valves,
alarms, etc., can all be turned off and
on to control the inventory inside of
that tank. Advantage: Multiple
level switches within one unit, price.
Disadvantages: float is a mobile
wetted part and can be interrupted by
flow, suspended solids, stickiness, etc.
- Liquid
Eye-Level Gauges. This type of
unit incorporates an oversized float inside
of the tank connected to a cable. The
cable exits the tank via a pulley system,
and is connected to a pointer which indicates
the level of the liquid on a calibrated
board mounted along the sidewall of the
tank. Advantage: Price is right,
especially for very large tanks, at about
$1200 ea. Float-counter weight system
is relatively foolproof. Relays can be
added for about $600 per pair. Disadvantage:
Primitive, and a close, visual accessibility
of the tank is usually required.
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Ultrasonic
Level Transmitter |
Ultrasonic Level Switch.
This type of unit
can indicate continuous levels throughout
the tank and can control instrumentation
at any level as many times as is required
- depending on the amount of relays placed
inside the digital display. This unit
observes the level by bouncing a radar
signal off of the surface and measuring
that distance to and from that surface.
Advantage: No wetted parts--
so failure of system is avoided regardless
of liquid characteristics. Disadvantage:
More expensive (from $1400 and up with
4 relay digital display box included);
thick heavy fume clouds can trigger faulty
signal.
- Load
Cells. These units actually weigh
the entire vessel and its contents and
continuously indicate weight via a display
while the tank is being filled, etc. The
display box can include relays wired to
control valves, pumps, alarms, mixers,
etc. which, in turn, can regulate the
contents of the tank. Advantage:
No wetted surfaces; in fact, the indicator
does not even need inside access to the
tank. Disadvantage: Expensive;
units start at about $2000 per tank (with
a digital display) depending on the total
"full capacity weight" of the
tank.
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