Note the installation practices for gas versus steam in the graphic below:
These installation techniques are done to
- prevent liquid condensation from collecting in the impulse tubing and creating measurement errors on a gas pipe.
- prevent steam from cooking/baking/overheating the pressure transmitter by isolating the transmitter from the steam with condensed water, which acts as a pressure transmission medium
- keep gas/air out of a liquid impulse sensing line by allowing any gas/air to rise back up to the flow line.
A seal pot or condensate pot is installed in the impulse tubing on a steam line. It is filled with water to isolate the transmitter.
Could the line be a former steam line, now used for water? The seal pot could be left over from steam service.
U r correct this is the normal installation technique for liquid/gas/steam services.
but here in this case if transmitter installed above tapping point for Gas service it is not accessible (no platform for access).that's why it has been advised to use seal pot and install the Tx below the tapping point...
do we need any filling liquid for this case?
will this kind of installation will provide any error on measurement?
To clear things up, the pots are referred to as condensate pots if they are used in gas service where the transmitter is mounted below the tapping not seal pots.
In this case the purpose of the pots is to collect the condensate which will inevitably form thereby preventing the accumulation of condensate in the impulse lines, the impulse lines must be kept free of condensate in order to prevent erroneous measurements since it is impossible that both impulse lines will fill at the same rate. There is no requirement for impulse lines in this type application to be liquid filled.
Seal post are used for steam flow applications in which case the transmitter should be mounted below the tapping and the impulse lines and the seal pot must be filled so as to protect the sensor from exposure to high temperature steam. Also it is inevitable that the impulse lines will fill with liquid since steam will condense once it exits the flow stream.
Seal Pot for Gas Service
Re: Seal Pot for Gas Service
