tank system protection overfill

  • Thread starter A. Edmundo Vega de la Garza
  • Start date

Thread Starter

A. Edmundo Vega de la Garza

Hi members list

Can Tank system protection overfill signals, use same cable wire used by level transmitter signals??

Which standard is used for that??

Tank system protection overfill is separate hardware of Level transmitter hardware.

Thanks and Best regards

A. Edmundo Vega de la Garza

Al Pawlowski, PE

I once put a Hi Level float switch in series with a loop powered, 4-20mA pressure transmitter measuring the level of a water tank. The
transmitter level controlled some tank-filling pumps. Operation was to keep the tank very near its overflow and the float switch guarded against transmitter calibration error and failure. If the level got too high, the loop was broken, the pumps shut off, alarms sounded and a below zero signal appeared on the remote level readout. An operator could easily tell that either his cable to the tank went out or he was about to overflow. There was/is no standard involved, but it worked
quite well. I put it in after a transmitter problem caused the tank to overflow and wash out the tank access road to the tune of about
$200,000. The float switch later saved two overflows to my knowledge and is still in operation twenty years later.

BTW, the transmitter failure was kind of interesting. The transmitter was a force balance unit of about late 1970's vintage and used a ceramic plate capacitor as its feedback sensor. Well, the capacitor plate turned out to be a pretty good bacterial growing surface if it got damp. When it got slimed, it would go out of calibration and read low.

Sumeet Chimalkar

You can use a trip amplifier (i think MTL and E&H manufacture them) and generate an alarm from the trasnmitter circuit which can be used to trip
your pumps. Let me know if you need a detailed scheme and/or model numbers.


Tank over fill protection may require some certifaction or approvals (I'm not the specialist) but visit www.solartron.com for overfill protection devices which will do what you want.