An instrument air header is defined as pressurized air that supplies a number of instruments, control valves, and other appliances within an industrial plant. These headers are customarily applied in the oil and gas, petrochemicals, and power production and many other sectors in which precise control is mandatory. It contains apart from cleaning and drying compressed air, regulating of compressed air that will enable correct working of the instruments and devices in the header.

In particular, it is necessary to indicate that instrument air headers are supposed to withstand pressure. They are usually stamped for pressure ranges of 150psi-1000 psi or according to the design requirements. However, it is required that the pressure rating of the instrument air header is able to address the requirements of the devices and systems that are to be supplied with compressed air by the instrument air header. Instrument air headers are standard as well as customizable depending on the flow rate and pressure needed. The size of the instrument air header must be determined, therefore, by the peak flow rate and absolute pressure that will be required to serve the devices and systems supplied with instrument air.