TIPS & TOOLS:  Do You Know What Is In Your Pipes?

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Anhydrous ammonia is considered a very high health risk that poses significant threat to those who work around it. To reduce the risk of worker exposure and prevent accidents, both the ANSI A13.1 standard (used for non-ammonia piping), along with The International Institute of Ammonia Refrigeration (IIAR), require thorough and specific labeling of all pipes and ducts that contain ammonia-based refrigerants.

All ammonia refrigerant piping should be identified in accordance with IIAR Bulletin #114. The identification system used has been standardized to prevent confusion and mis-interpretation. All ammonia pipe markers have a standard layout of the information required.  This layout is divided into (5) sections.  These sections are as follows:

1. Marker body
2. Physical state
3. Pressure level
4. Abbreviation
5. Direction arrow

The marker body is the yellow background and varies in size depending on the total diameter of the pipe plus the insulation.

The physical state is liquid, vapor or a combination of both.

The pressure level is either low or high.

The abbreviation is an acronym which describes the state of the ammonia in the pipe. (Example: LTRS is a Low Temperature Recirculated Liquid.) This is in accordance with IIAR Bulletin #114 section 4.1.4.

The direction arrow shows the direction of refrigerant flow. 

Typically a sticker type of marker is used on interior pipe which will adhere to the insulation jacket or painted pipe. The arrows are scored to allow for applying them in the correct direction. 

The typical location of a pipe marker is:

• Before and after a change in pipe direction
• Before and after pipe penetrations of walls, ceilings and floors
• On extended horizontal or vertical runs of pipe, no more than 40 feet between markers
• At least once on the piping in every area through which the refrigeration piping passes

Visibility is as important as spacing. Pipe markers should be placed so that they can be easily read.

Exterior pipe markers should be able to stand up to a multitude of weather conditions. Between the sun, the snow, the rain and the passing of time a typical sticker will fade, crack and in most cases peel off. There are marking systems that take this into account and will specify a carrier or polyester wrap-around style marker for exterior use.

A carrier type marker is typically a sticker, same layout as above that is laminated to a plastic carrier and strapped tightly onto the pipe using stainless steel straps.   A polyester wrap-around wraps the pipe and has an adhesive seal that keeps it on the pipe.  The carrier is typically used on 8” diameter pipe and larger.  The polyester wrap around is typically used for 6” pipe and smaller.

Whether your need is large or small, inside or outside, we are here to help you mark your ammonia system for your safety and that of your coworkers and employees.