Storage and Handling of Anhydrous Ammonia §1910.111(b)(3), (4), (8), (9), (13); (e)(1); (g)(5)

Marking Nonrefrigerated Containers

System nameplates, when required, must be permanently attached to the system. All containers covered in §1910.111(c), (f), (g), and (h) have to be marked as follows:

• With a notation "ANHYDROUS AMMONIA."
• With marking identifying compliance with the rules of the Code under which the container is constructed.
  • Under ground: Container and system nameplate
  • Above ground: Container
• With a notation whether the system is designed for under ground or above ground installation or both.
• With the name and address of the supplier of the system or the trade name of the system and the date of fabrication.
  • Under ground and above ground: System nameplate
• With the water capacity of the container in pounds at 60°F or gallons, U.S. Standard.
  • Under ground: Container and system nameplate
  • Above ground: Container
• With the design pressure in pounds per square inch.
  • Under ground: Container and system nameplate
  • Above ground: Container
• With the wall thickness of the shell and heads.
  • Under ground: Container and system nameplate
  • Above ground: Container
• With marking indicating the maximum level to which the container may be filled with liquid anhydrous ammonia at temperatures between 20°F and 130°F except on containers provided with fixed level indicators, such as fixed length dip tubes, or containers that are filled with weight. Markings shall be in increments of not more than 20° F.
  • Above ground and under ground: System name plate or on liquid-level gaging device
• With the total outside surface area of the container in square feet.
  • Under ground: System nameplate
  • Above ground: No requirements
• Marking specified on the container has to be on the container itself or on a nameplate permanently attached to it.

Marking Refrigerated Containers

Marking specified on the container has to be on the container itself or on a nameplate permanently attached to it. Each container has to be marked as follows:

• With the notation "ANHYDROUS AMMONIA."
• With the name and address of the builder and the date of fabrication.
• With the water capacity of the container in gallons, U.S. Standard.
• With the design pressure.
• With the minimum temperature in degrees Fahrenheit for which the container was designed.
• With the maximum allowable water level to which the container may be filled for test purposes.
• With the density of the product in pounds per cubic foot for which the container was designed.
• With the maximum level to which the container may be filled with liquid anhydrous ammonia.

Hose Specifications

All hose ½ inch outside diameter and larger, used for the transfer of anhydrous ammonia liquid or vapor, must be etched, cast, or impressed every 5 feet with the following:

"ANHYDROUS AMMONIA" XXX p.s.i.g. (maximum working pressure), manufacturer's name or trademark, year of manufacture.

The same information may be contained on a nameplate permanently attached to the hose instead of the above requirement.

Safety Relief Devices

Every container safety-relief valve used with systems covered by §1910.111(c), (f), (g), and (h) of this section shall be plainly and permanently marked as follows:

• With the symbol "NH₃" or "AA";
• With the pressure in pounds-per-square inch gage at which the valve is set to start-to-discharge;
• With the actual rate of discharge of the valve at its full open position in cubic feet per minute of air at 60°F and atmospheric pressure; and
• With the manufacturer's name and catalog number.

For example, "NH₃ 250–4050 Air" indicates that the valve

• is suitable for use on an anhydrous ammonia container,
• is set to start-to-discharge at a pressure of 250 p.s.i.g., and
• that its rate of discharge at full open position is 4,050 cubic feet per minute of air.