State offices and all DLLR physical locations will be closed to the public December 24 & December 25, 2014. However, Unemployment Insurance telephone and Web operations WILL be available on Wednesday, December 24.

DLLR's Division of Labor and Industry


Do's and Don'ts of Compressed Air Storage Tank Operations - Boiler and Pressure Vessel Safety - Safety Inspections


The following is a partial list of operational hints that will provide a safer, more economical, and longer operating life for your compressed air storage tank.


  • Operate an air tank which is not constructed to meet the requirements of the American Society of Mechanical Engineers (A.S.M.E.) Code.
  • Operate air tank which is not equipped with a functional A.S.M.E. Code safety relief valve set at or below an established maximum working pressure.
  • Mount the vessel rigidly without vibration buffer supports under tank legs.
  • Ever operate a vessel without a properly equipped and operating pressure gauge!
  • Ever bypass the pressure control switch, or any switches, which control pressure.
  • Ever restrict the design function of any safety relief valve-for example; tie down, paint, block, cap, or remove.
  • Make welded repair on air tanks.
  • Use plastic pipe for any air discharge line.
  • Pile stock up against the tank.


  • Respect the pressure vessel. It can be dangerous!
  • Test the safety relief valve monthly.
  • Drain condensate from the tank regularly-daily, if necessary.
  • Keep vessel mounted level at all times with vibration protection in place.
  • Have the vessel inspected biannually, as required by State law.
  • Protect tank from damage caused by vehicle traffic or plant operations.
  • Inspect at least weekly for air leaks.  If you find an air leak, determine its source (i.e. line, fitting or crack).
  • Report new installations to the State Office of Boiler and Pressure Vessel Safety.
  • Have all welded repairs made only by companies holding the "R" stamp authorization or the A.S.M.E. "U" symbol.

Quick Links:

For additional information, contact:
Division of Labor and Industry
Boiler and Pressure Vessel Safety

1100 N. Eutaw Street - Room 605
Baltimore, MD 21201
(410) 767-2330
FAX: (410) 333-7827

Emergency telephone number:  (410) 767-2990