Hello, we need to find the exact level of ammonia inside a closed tank as it has problems with the level gauges and a new transmitter has just been installed. However, to prevent the tank from being overfilled with ammonia, has happens often, we want to know the exact level.

Is this possible to perform by attaching a druck DPI into the tank discharge pipework?

What calculation is required to convert from mm H2O/mbar etc to measure the level of hydrostatic head.

Cheers in advance

 

I assume your tank is under pressure so you will need a DP cell with the LP tap connected to the vapour space or padding system. Yes you can connect to the discharge piping and offset to match the bottom of the tank assuming the connection point is below bottom otherwise you will only be able to measure above that level.

There is one problem however, when flowing you will get a pressure drop due to flow which will indicate a level lower than actual.
It's always better to connect your transmitter to a dedicated connection however I presume you are faced with connecting to an existing installation with no spare connection

Regards
Roy

 

Use of a tank roof mounted Honeywell-Enraf series 854 servo gauge, you can't go wrong. check out www.honeywellenraf.com.