How to measure water level in closed tank
Measurement of level of water in the Boiler drum is a classic example of water level measurement in a closed tank. In this case, as water in the drum gets heated, it turns into steam and builds up pressure above the water which is more than atmospheric pressure.
Closed water tanks are also made use of in high-rise buildings for domestic water supply. By providing pressurized underground water tank, the need for deep and extra strong foundation for the building can be avoided, which otherwise would have been needed in case of an overhead water storage tank. The underground tank is kept under pressure by compressed air. As compared to the “open to atmosphere” tank, in a closed tank, the pressure above water may change due to consumption of water from the tank or by addition of water into the tank.
Measurement/detection of water Level in closed tank can be done by various methods and by making use of various types of instruments. PTPL manufactures a large variety of instruments required for this purpose.
A] Direct reading level gauges:- Tubular Level Gauge - TTG, Reflex Glass Level Gauge- RFG, Transparent Glass Level Gauge – TFG, Magnetic Level gauge- MLG, These gauges are also available as IBR approved gauges for boiler drum level applications.
B] Level switches:- Float Pivoted Switch- FPS, Float Guided Switch –FGS, Displacer Switch-DS, Capacitance Switch – CPS, Conductivity Switch – CNS, Chamber Float Switch- CFS, Mobrey Type Vertical Level Control- VLC. Suitable switch can be selected from this range depending upon temperature & pressure rating
C] Level transmitters:-- Float Guided Transmitter- FGT, Capacitance Transmitter-CPT , Ultrasonic Transmitter- Ultratrol, Radar Transmitter, Guided Wave radar Transmitter,, Displacer Type Transmitter – DTT, Differential pressure Transmitter – DPT. Suitable transmitter can be selected from this range depending upon temperature & pressure rating