Air receivers requirements

This section applies to compressed air receivers and equipment used to provide and use compressed air for operations like cleaning, drilling, hoisting, and chipping. Employers must follow 1910.169(a)(1).

• It does not cover special problems created by using compressed air to convey materials or when people work in compressed-air environments such as tunnels and caissons.
• It is not intended to apply to compressed air machinery and equipment used on transportation vehicles (for example, steam railroad cars, electric railway cars, or automotive equipment).

(Reference: 1910.169(a)(1)).

Yes — all air receivers installed after the effective date must be constructed to the 1968 edition of the A.S.M.E. Boiler and Pressure Vessel Code, Section VIII. See 1910.169(a)(2)(i).

• That ASME code is incorporated by reference as specified in 1910.6, so employers should follow the ASME Section VIII (1968) rules for design, materials, and construction of new receivers.

(Reference: 1910.169(a)(2)(i) and 1910.6).

All safety valves used on air receivers must be constructed, installed, and maintained in accordance with the A.S.M.E. Boiler and Pressure Vessel Code, Section VIII, Edition 1968. See 1910.169(a)(2)(ii).

• Follow the ASME Section VIII (1968) rules for valve material, set pressure, discharge capacity, and installation details.
• Because ASME Section VIII is incorporated by reference under 1910.6, use the code and manufacturers’ instructions to meet OSHA’s requirement.

(Reference: 1910.169(a)(2)(ii) and 1910.6).

An air receiver must be installed so that all drains, handholes, and manholes are easily accessible; it must not be buried underground or placed where those openings are inaccessible. See 1910.169(b)(1).

• Make sure personnel can reach and operate drain valves and remove handhole/manhole covers for inspection or maintenance without excavation or unsafe maneuvers.

(Reference: 1910.169(b)(1)).

Every air receiver must have a drain pipe and valve installed at its lowest point to remove accumulated oil and water, and the drain valve must be opened and the receiver completely drained frequently enough to prevent excessive liquid accumulation. Adequate automatic traps may be used in addition to manual drain valves. See 1910.169(b)(2).

• Install the drain at the lowest point and provide an accessible valve.
• Use automatic traps if appropriate, but do not rely solely on them without an accessible means to fully drain the receiver.
• Establish and follow a drainage schedule based on system use and manufacturer guidance.

(Reference: 1910.169(b)(2)).

Every air receiver must have an indicating pressure gage that is readily visible and one or more spring-loaded safety valves. See 1910.169(b)(3)(i).

• Mount the pressure gage so operators can see the indication during normal operations.
• Install at least one spring-loaded safety valve; multiple valves may be used to provide the required relieving capacity.

(Reference: 1910.169(b)(3)(i)).

No — you may not place any valve of any type between the air receiver and its safety valve or valves. See 1910.169(b)(3)(ii).

• This prevents isolation of the safety device and ensures the safety valve can relieve pressure if the receiver overpressurizes.

(Reference: 1910.169(b)(3)(ii)).

Safety appliances, including safety valves and indicating or controlling devices, must be constructed, located, and installed so they cannot be readily rendered inoperative by any means, including weather or environmental elements. See 1910.169(b)(3)(iii).

• Protect devices from corrosion, freezing, physical damage, and tampering by appropriate housing, piping arrangement, or barriers.
• Locate gauges and valves where they can be maintained without disabling them.

(Reference: 1910.169(b)(3)(iii)).

The total relieving capacity of the safety valves must be sufficient to prevent the pressure in the receiver from exceeding its maximum allowable working pressure (MAWP) by more than 10 percent. See 1910.169(b)(3).

• Use ASME Section VIII (1968) and valve manufacturer data to calculate required capacity.
• Multiple valves can be used to achieve the necessary total relieving capacity.

(Reference: 1910.169(b)(3) and 1910.169(a)(2)(i)).

Safety valves must be tested frequently and at regular intervals to confirm they are in good operating condition, but the standard does not set a specific interval; employers must establish and follow an appropriate testing schedule. See 1910.169(b)(3)(iv).

• Determine frequency based on manufacturer recommendations, the environment (corrosive or high-use), operating history, and applicable ASME guidance (1910.169(a)(2)(i)).
• Keep records of tests and maintenance to demonstrate compliance.

(Reference: 1910.169(b)(3)(iv) and 1910.169(a)(2)(i)).

Yes — adequate automatic traps may be installed in addition to drain valves, but they do not replace the requirement to provide a drain pipe and valve at the lowest point and to open and completely drain the receiver frequently enough to prevent excessive liquid accumulation. See 1910.169(b)(2).

• If using automatic traps, still provide an accessible manual drain for complete draining and maintenance.
• Establish procedures to inspect and maintain traps so they do not block proper drainage.

(Reference: 1910.169(b)(2)).

No — an air receiver must not be buried underground or located in an inaccessible place; drains, handholes, and manholes must be easily accessible. See 1910.169(b)(1).

• If below-grade placement is unavoidable, ensure safe, routine access for draining, inspection, and maintenance consistent with the standard.

(Reference: 1910.169(b)(1)).

The standard requires an indicating pressure gage that is readily visible, but it does not specify a particular brand or model; choose a gage suitable for the receiver’s pressure range and service and mount it so it can be read during normal operations. See 1910.169(b)(3)(i).

• Select a gage with a range that places normal operating pressure well within the dial for accurate reading.
• Protect the gage from mechanical damage and environmental degradation per 1910.169(b)(3)(iii).

(Reference: 1910.169(b)(3)(i)).

The standard requires that all new air receivers installed after the effective date be constructed per the 1968 ASME Boiler and Pressure Vessel Code Section VIII; it does not automatically require that existing receivers be rebuilt to that code when repaired. See 1910.169(a)(2)(i).

• When repairing or altering an existing receiver, follow applicable safe repair practices and the manufacturer’s recommendations; if a repair changes the vessel’s design pressure or construction materially, consult ASME code and a qualified engineer.
• Employers should document repairs and ensure safety valves, drains, and gauges meet the installation and maintenance requirements found in 1910.169(b).

(Reference: 1910.169(a)(2)(i)).

An employer may use one or more spring-loaded safety valves, but the total relieving capacity of the installed valves must prevent the receiver pressure from exceeding MAWP by more than 10 percent. See 1910.169(b)(3)(i) and 1910.169(b)(3).

• Use one valve only if its rated capacity meets the required relieving capacity; otherwise install multiple valves sized to provide the required total capacity.
• Follow ASME Section VIII (1968) for valve sizing and set pressures per 1910.169(a)(2)(i).

(Reference: 1910.169(b)(3)(i) and 1910.169(b)(3)).

If a pressure gage or safety valve becomes inoperative, the employer must repair or replace it promptly and ensure safety appliances are installed and maintained so they cannot be readily rendered inoperative, per 1910.169(b)(3)(iii).

• Tag the equipment out of service or take it offline if necessary to protect workers until repairs are completed.
• Test safety valves after repair to confirm proper operation per 1910.169(b)(3)(iv).

(Reference: 1910.169(b)(3)(iii) and 1910.169(b)(3)(iv)).

Determine the MAWP from the air receiver’s nameplate, manufacturer documentation, or engineering calculations performed to recognized codes such as the A.S.M.E. Boiler and Pressure Vessel Code, Section VIII (1968), which new receivers must meet per 1910.169(a)(2)(i).

• If the MAWP is not clearly documented, consult the manufacturer or a qualified pressure-vessel engineer and follow ASME code requirements referenced by 1910.169(a)(2)(i).
• Use MAWP to establish safety valve set pressures and required relieving capacity so receiver pressure cannot exceed MAWP by more than 10% as required by 1910.169(b)(3).

No — you must not place any valve of any type between the air receiver and its safety valve(s) per 1910.169(b)(3)(ii), so bypassing or isolating the safety valve while the receiver is pressurized is not permitted. Safety valves must remain capable of relieving pressure and must be tested and maintained per 1910.169(b)(3)(iv).

• For maintenance that requires removing a safety valve from service, de-pressurize and safely isolate the receiver according to established procedures before disabling any safety device.

(Reference: 1910.169(b)(3)(ii) and 1910.169(b)(3)(iv)).