Low flow measurement 

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Low flow meters for a variety of low flow applications in nuclear power plant applications. 

1.  For measuring low flow gas of WGS in PWR, design flow is from 0 to 3m3/h, normal flow is about 0.99 m3/h in working condition.

2.  The containment air cooler drain lines in PWR and BWR plants. Increases in the line flow can indicate increases in containment humidity due to unidentified leakage.

3. For measuring CRDM flow out of the reactor. Coolant flow is pumped to 4 banks of control rod drive mechanisms by a fixed speed pump to cool the components from reactor temperatures. Most of this flow goes into the reactor, but some goes through four drain lines to the sump. The flow into the reactor is determined by the total pump flow minus the drain flow, and has a small (~0.02%) impact on calculated reactor power.

4.   Measuring seal leakage on coolant pumps for PWR plants. This allows accurate determination of identified leakage and the need to replace pump seals.


Intek’s In-line Model 210 thermal mass flow meter and Cameron’s Flow watch LF both can provide accurate and dependable measurements for low flow applications



Intek In-line Model 210

The Intek’s thermal measurement method employs two Resistance Temperature Detectors (RTDs) to measure flow. One RTD measures the fluid temperature, and the other RTD measures the temperature of a constant low-power heater which is cooled by the flowing fluid. The temperature differential between the heated and unheated RTDs provides the primary flow signal. 

TU/TUL sensors incorporate an unobstructed flow path. The meter size as low as 1/16 inch. In-line Model 210 can provide measurement both for liquid and gases.

Low flow liquid as low as 10 CC/day; and gases as low as 20 SCCM

Cameron/Caldon   Flow Watch™ LF

The Flow Watch LF uses two transducers forming a single full cross section acoustic path (red section shown in the above cutaway diagram). The specially designed transducers create a cone of acoustic energy down the axis of the meter that encompasses the whole cross section area –reflecting off the mid point of the meter.

The Flow Watch LF ultrasonic flow meter is designed to measure low flows and extends our Flow Watch to meter sizes 3 inches and smaller.