Power Plant Service Air System Design


Design service air system in power plant should be performed to assist equipment running well. The service air system should be provided and should include but not limited to the following equipment should be supplied.

  • Oil free, screw type compressors with a sufficient capacity
  • After coolers and separators
  • Air receivers
  • Acoustic enclosure to house compressors and ancillary equipment
  • All piping, valves and support in accordance with relevant section of this specification
  • All instrumentation including fittings, valves and installation materials
  • All electrical equipment and wiring associated with the above equipment, including local compressor control and selector panels.

Design Requirements

The total service air requirements for the station should be supplied from control compressed air plant within in enclosure in air compressor house. Complete isolation of items of plant should be provided. An emergency supply pipeline to the instrument air receiver, common header, should be provided to connect a suit the valve supplied to the instrument air system.

The air will pass from the discharge of each compressor through individual after coolers and separators to the air receiver. Each receiver will discharge into a common line. All take off connection from horizontal headers should be from the top of mains.


Each compressor should deliver oil free air and should be supplied with the following:

  • Water cooled intercooler with safety valve and moisture separator.
  • Air intake filter and silencer to reduce noise.
  • Unloading mechanism and piping.
  • Relief valve
  • All control (local control panel), electrical and protection equipment to ensure safe and reliable operation of the plant.

After coolers and Separators

Each compressor should be supplied with an after cooler and moisture separator complete with all necessary fittings, relief valves and automatic drainage facility.

Air Receivers

The service air system can be provided as vertical air receivers. The receivers should be of all welded construction and should conform to the requirements of ASME Section Vlll “Pressure Vessel" Division I. The receivers should be supplied complete with the out connections, manhole, drain connection, pressure gauges, relief valves and instrument connections.

Quick Coupling Connection and Rubber Hose

Female and male quick coupling connection and minimum 25 meter rubber hose should be provided for every isolating valve.

The service Air system should serve the following building not limited to:.

  • Steam Boiler
  • Steam Turbine
  • Particulate Extraction Equipment
  • Coal Bunker
  • CW Pump House
  • Water Treatment Plant
  • Waste Water Treatment
  • Fuel Oil Pump House
  • Bulldozer Garage
  • Coal Transfer Tower
  • Ash Silo
  • Chlorination system