Calibration; Hydraulic Shock; Thermal Shock; Products That Dry/Congeal/Crystallize - Total Control Systems 700-20 Engineering Manual

Thermal Shock

The system operating temperature will expand or contract the metals within the flow meter. For systems
sudden or immediate temperature increases of 68 F (20 C) degrees or more, will require
that have
clearance rotors. Clearance rotors will be necessary to eliminate the effect of immediate
expansion of the rotors vs. meter body, caused by thermal shock.
Hydraulic Shock (Water Hammer)
Hydraulic shock is a rise in pressure, which happens when an operating system has immediate
change in direction of flow such as a fast valve closure at a high operating flow rate. Hydraulic
shock can damage any item in the way of the product flow such as internal parts of the meter,
valves, and pump. System design and improper operating procedures will elevate this problem.
The use of 2-stage preset control valves or surge suppressing bladders or risers will help reduce
or eliminate this problem.
To compute the shock pressure when a valve is closed quickly (recommended to be less than 6
PSI):
In order to eliminate hydraulic shock, you need to slow down the valve closure rate. The time
required to close the valve so that the line pressure will not exceed the normal pressure at no
flow is:
V = Velocity in Feet/Seconds
L = Length of pipe before the valve in feet
N = Line pressure at no flow
F = Line pressure at full flow

Products that Dry/Congeal/Crystallize

There are many liquids that crystallize, harden and/or solidify on contact with air or with an
increase in temperature. A proper system design and a good understanding of the product being
measured will help to avoid the possibility of air entering into the system and the product being
affected.

Calibration

The meter shall be tested and calibrated with the product it is intended to measure when installed.
Total Control Systems shall not be responsible for loss of product or any damages resulting from
the end user's failure to test this meter to insure proper calibration. Every 700 series meter is
tested and calibrated at the factory to prove it is calibratable in your system. It is the owner's
responsibility to report this device to the local Weights and Measures officials for their
inspection before the meter is put to use. Refer to the Material Safety Data Sheet of the
calibration fluid used in testing on pages 43 to 46 for more information.
Shock Pressure (PSI) = 63 x Velocity (FPS)
Time (seconds) = 0.027 x L x V
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N – F