Skip to main content


Air Tank and Compressor Inspection and Permit

January 26, 2023 11454

California requires a permit for any air tank that is 11/2 cubic feet in volume or larger or when the safety valve is set greater than 150 psi. Operating an air tank without a permit or without requesting a permit constitutes a misdemeanor.

The law, California Labor Code Sections 7620-7771 and CCR 8 Section 450 et seq., applies to most business types.

Inspectors from the Cal/OSHA Pressure Vessel Unit conduct safety checks on tanks and compressors for the purpose of issuing and renewing permits only. They do not inspect the workplace for compliance with other Cal/OSHA regulations.

The inspection should not interfere with the normal operations of a dental office. Inspectors use an ultrasonic device to measure thickness of the steel and compare it with the information on the name plate. If the drain and dryer on a compressor are not working properly, the steel on the tank can rust. Inspectors ensure the tank, compressor and all its parts function. They ensure the safety relief valve, manual drain and pressure gauge are present and functioning. They check for leaking, cracked or defective tanks and ensure there are no electrical problems. Schedule 80 pipe is required from the tank to the first stop valve in both directions. PVC piping is not allowed; oil and sunlight make the plastic brittle.

A permit for a portable tank expires three years from the date of inspection and, for all other air tanks, five years from date of inspection. Air tanks subject to a maximum allowable working pressure not exceeding 150 psi, as shown by the required code marking, and having a volume of 25 cubic feet or less must be inspected when placed into service. An indefinite permit will be issued provided that the tank has been constructed, inspected and stamped in compliance with the American Society of Mechanical Engineers (ASME) Code or the design, material and construction of the tank is accepted by Cal/ OSHA as equivalent to the ASME Code and the tank is in compliance with the applicable regulations. A new inspection and permit for operation is required whenever there is a change of ownership and permanent location of the tank or there is an alteration or change in the tank that affects the tank’s safety.

Air tanks must have ASME stamp similar to this one:

A fee of $150 per hour is charged to the tank owner for inspection, travel and administration. In practice, inspectors schedule visits to several businesses in a day, then charge each business an equal share of the day’s inspection, travel and administrative charges. Each tank permit is $45 for a term of five years. Inspections can be scheduled by calling the Northern California office in Oakland, 510.622,3066, or the Southern California office in Santa Ana, 714.567.7208, of the Cal/OSHA Pressure Vessel Unit. Alternately, you can download an Inspection Request Form, complete it and return it to the appropriate regional office. The pressure vessel unit does send out letters confirming a business’ request for inspection. This letter is adequate proof of intent to comply with the regulation should a business be inspected by Cal/OSHA enforcement staff.

Inspections of tanks and air compressors can be conducted by other state-certified inspectors. However, these other inspectors are usually employed by risk insurance companies who offer the inspection service to their clients. Dental practices do not typically carry risk insurance, and it is unlikely that an insurance company would provide a service to a non-client.

Comments are only visible to subscribers.