Differential pressure level transmitter

ISA 5.1-2009/2022 (primary element symbols) / PIP PIC001

Drawn as

An LT bubble with two impulse lines to the vessel: one from a low nozzle (high side) and one from a high nozzle (low side). Remote seals are drawn as capillaries (line with × marks).

Meaning

Level from hydrostatic head: the most common level transmitter on separators and drums. Becomes dp-transmitter; the bubble letters (LT) give the service.

Variants

With diaphragm seals the lines carry × marks (capillaries)
Bubble-tube (purge) level measurement looks similar with a purge supply