Liquid Controls MA4 Meter - Manual (Page 3)

3
How LC Meters Work
Liquid Controls meters are positive displacement meters.
They are designed for liquid measurement in both
custody transfer and process control applications. They
can be installed in pump or gravity flow systems. Because
of their simple design, they are easy to maintain, and
easy to adapt to a variety of systems.
The meter housing (1) is designed with three cylindrical
bores (2). Three rotors, the blocking rotor (3) and two
displacement rotors (4, 5), turn in synchronized
relationship within the bores. The three rotors are
supported by bearing plates (6, 7). The ends of the
rotors protrude through the bearing plates. Blocking rotor
gear (8) is placed on the end of the blocking rotor.
Displacement rotor gears (9, 10) are placed on the ends
of the displacement rotors. These gears create the
synchronized timed relationship between the three rotors.
As fluid moves through the meter housing, the rotor
assembly turns. The liquid is broken into uniform sections
by the turning rotors. Fluid displacement happens
simultaneously. As fluid enters, another portion of the
fluid is being partitioned and measured. At the same
time, the fluid ahead of it is being displaced out of the
meter and into the discharge line. Since the volume of
the bores is known, and the same amount of fluid passes
through the meter during each revolution of the blocking
rotor, the exact volume of liquid that has passed through
the meter can be accurately determined.
This true rotary motion is transmitted through the packing
gland, the face gear, the adjuster drive shaft, and the
adjuster to the register stack and counter. True rotary
motion output means consistent accuracy since the
register indication is in precise agreement with the actual
volume throughput at any given instant.
At any position in the cycle, the meter body, the blocking
rotor, and at least one of the displacement rotors form a
continuous capillary seal between the un-metered
upstream product and the metered downstream product.
Capillary seals mean no metal-to-metal contact within
the metering element. This means no wear. No wear
means no increase in slippage, and no increase in
slippage means no deterioration in accuracy.
Throughout the metering element, the mating surfaces
are either flat surfaces or cylindrical faces and sections
that are accurately machined. These relatively simple
machining operations, plus the fact that there is no
oscillating or reciprocating motion within the device,
permits extremely close and consistent tolerances within
the LC meter.
The product flowing through the meter exerts a dynamic
force that is at right angles to the faces of the
displacement rotors. The meter is designed so that the
rotor shafts are always in a horizontal plane. These two
facts result in no axial thrust. Therefore, with no need
for thrust washers or thrust bearings, the rotors
automatically seek the center of the stream between the
two bearing plates eliminating wear between the ends
of the rotors and the bearing plates. Once again, no
wear results in no metal fatigue and no friction.
The Liquid Controls meters are made of a variety of
materials to suit a variety of products. Because of our
no-wear design, capillary seals, and unique rotary
metering, LC meters provide unequalled accuracy, long
operating life, and unusual dependability.
4. See that the gas is dispersed before resuming
business and operating motors. If in doubt, notify
your local fire department.
In the Event of a Gas Fire
In the event of large fires or fires that are spreading:
Evacuate the building and notify your local fire
department. Stop the leakage only if you can safely reach
the equipment.
In the event of small, contained fires that you can
safely control: Stop the leakage if you can safely reach
the equipment. Then use the appropriate extinguisher:
Class B fire extinguisher, water, fog, etc., depending on
the materials. If in doubt, call your local fire department.
Meter Element Exploded View