Division of Labor and Industry


Keep Your Boiler Room Safe - Compressed Air Tanks - Boiler and Pressure Vessel Safety - Safety Inspections


Keep Your Boiler Room Safe - Compressed Air Tanks (Word document, download Word viewer for free)

Objective: To educate the public on the safe and proper use of Unfired Pressure Vessels containing Compressed Air.

An Air Receiver is probably the most common type of unfired pressure vessel. However due to minimum size inspection thresholds employed by the State of Maryland, many of the smaller air receivers will not qualify for a mandatory in-service inspection.

The typical inspection threshold sizes in jurisdictional regulations are 5 cubic feet and 250 psi, or 1.5 cubic feet 600 psi.

Air receivers shall be constructed in accordance with ASME BPV Code Section VIII and are stamped with the ASME "U" or "UM" symbol.


  • Drain the Air Tank daily of moisture to prevent internal corrosion.
  • Install a safety valve set at or below MAWP and sufficient relieving capacity.
  • Install a pressure gauge
  • Keep your Boiler Room clean.
  • Keep a check on leakages and rectify without delay.
  • Don't store flammables in the Boiler Room.
  • In an emergency, remain calm and use the emergency devices.
  • In case of fire operate Emergency cut off switch.
  • Maintain a Boiler Operation Log.
  • Keep the Boiler Room ventilated


Have the air receiver inspected biennially, as required by State Law.

Report to the Chief Boiler Inspector for the air receiver to be installed, at least 30 days prior to installation.

Test safety relief valve and log the tests.

Inspect the air receiver daily for proper operation.

Allow only authorized ("R" stamp holder) repair firms to make weld repairs.

Do Not----

  • Allow the pressure inside the tank to exceed the MAWP (Maximum Allowable Working Pressure).
  • Remove, plug or alter the safety relief valve setting.
  • Tamper with the pressure controls.
  • Bump or dent the air tank.
  • Install the tank on a foundation without vibration dampers.
  • Shut the automatic condensate drain.
  • Operate the Air Tank with an expired inspection certificate.
  • Impart excessive loading on the Air Receiver components.

We are here for your protection.

For additional information, contact:
Division of Labor and Industry
Elevator and Escalator Safety

1100 N. Eutaw Street - Room 601
Baltimore, MD 21201
Fax: 410-333-7721
e-mail: dldlisafetyinspection-dllr@maryland.gov

Emergency telephone number: 410-767-2990