Total Control Systems 700-20 Engineering Manual page 4

DESIGN
The TCS Model 700 series flow meter is a simple
and efficient design. The meter consists of a single
fluid chamber that contains a single blocking rotor
and two displacement rotors whose rotation is
synchronized with mating gears. As the fluid
enters the fluid chamber, the blocking rotor is
forced to rotate. The displacement rotors, also
rotating in conjunction with the blocking rotor help
direct the fluid flow through the chamber and to the
outlet. The linear flow of the fluid is thus
translated into rotary motion in the meter. The
output of the meter is picked up from the rotation
of the blocking rotor and transmitted to a register or
pulse transmitter.
The rotors in the meter are designed to operate at close tolerances to one another and the wall of
the fluid chamber. There are slight gaps between the rotors and the chamber wall. Because of
this, it is important that the meter be properly applied for the flow rate and operating pressure of
the system.
Because the fluid flowing through the meter is redirected only slightly from its natural flow,
there is very little pressure drop across the meter, unlike other meters that use multiple measuring
chambers.
The meter design uses high quality long life materials for the rotor bearings and journals. Since
there is no contact between the rotors and the fluid chamber wall, these critical components have
a long life expectancy.
Calibration of the meter involves adjusting the rotation of the output shaft relative to the rotation
of the internal rotors of the meter. This is accomplished by changing the settings on an adjuster
device. Calibration of the meter is discussed in detail in the section Meter Calibration.
700 METER FLOW ILLUSTRATION
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