Instrument air line
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I have a question: What is an instrument air line? ? ? ? Where is it specifically used in instruments in practice? ? And how is it usually represented in flowcharts? ?
Waiting to study*. . . . . . . . .
The instrument air line is the pipeline that delivers instrument air to pneumatic instruments. It is not shown in the instrument flow diagram; there is a separate diagram specific to the instrument air system. It is generally used for pneumatic control valves (both control valves and shut-off valves require it)
Reply 2# ydw629 is the pipeline used to supply instrument air, and it is usually made of galvanized steel pipes. Piping marked with the medium IA refers to instrument air ducts as piping. Used on pneumatic valves.
Reply 1# chenwenchao0127 Instrument air is also known as control air; add pipelines to it and it becomes an instrument air pipeline
The instrument air line is generally referred to as the air supply pipeline in instruments; it is used for pneumatic control valves, shut-off valves, or for backwashing instruments. It is not shown on the process PID diagrams – there are separate schematic drawings for the instrument air pipeline system. Typically, the main pipelines are made of 2” galvanized pipes, while the branch pipelines use 1/2” or 3/4” galvanized pipes. An air supply valve is installed before the control valve, and pipes made of stainless steel or copper with a diameter of 6–10 are used after the valve. Process instrument air is generally supplied separately from instrument air for instruments; process instrument air is usually denoted by IA on PID diagrams.
In the common sections of a flow diagram, instrument air ducts usually follow a main pipeline layout; branch pipelines are generally not present, as they are allocated based on the actual conditions on site