RAGAGEP: Codes, Standards, and Good Engineering Practices (Part 4)
Peter Thomas, P.E. recently wrote a technical paper and presented at the 2017 RETA National Conference on the topic of RAGAGEP: Codes, Standards, and Good Engineering Practices. This is the fourth in a series of blogs which include excerpts from his technical paper. The previous blogs are available in the following links: Part 1, Part 2, and Part 3.
RAGAGEP is often confusing due to the number of codes and standards implicitly able to be invoked by reference. In addition to the sheer number of published documents, it is also common practice for one code/standard to reference another; adding yet another layer of confusion.
In Amy A. Duz’s presentation at the 2013 RETA Conference, she cleverly stated that code compliance “is the Russian nesting doll of regulation. Once you open regulations, you find codes, open a code and you find another, open that code and you find a consensus standard, maybe another, and on and on.”
To illustrate, imagine an ammonia refrigeration system that is being built in an area where the 2015 International Mechanical Code is the governing code enforced by the Authority Having Jurisdiction (AHJ). Chapter 11 of 2015 IMC references two standards for compliance:
2015 IMC §1101.6 General
Ammonia-refrigerating systems shall comply with this code and, except as modified by this code, ASHRAE 15 and IIAR 2.
Each of these standards in turn, references several other codes/standards:
ANSI/IIAR 2-2014 §220.127.116.11
Cast iron, malleable iron, nodular iron, steel, cast steel, and alloy steel shall be permitted in accordance with ASME B31.5 or ASME B&PVC, Section VIII, Division 1…
ANSI/IIAR 2-2014 §6.7.3
Emergency eyewash/safety shower unit installations shall comply with ANSI/ISEA Z358.1.
ANSI/IIAR 2-2014 §6.15.1
Buildings and facilities with refrigeration systems shall be provided with placards in accordance with NFPA 704 and the Mechanical Code.
ANSI/ASHRAE 15-2013 §11.2.2(b)
Systems containing more than 110 lb (50 kg) of refrigerant shall be provided with durable signs having letters not less than 0.5 in. (12.7 mm) in height designating:
b…Valves or piping adjacent to valves shall be identified in accordance with ANSI A13.1, Scheme for Identification of Piping Systems.
ANSI/ASHRAE 15-2013 §8.5
Electrical Safety. Electrical equipment and wiring shall be installed in accordance with the National Electrical Code and the requirements of the AHJ.
A visual depiction of the codes / standards referenced in this example is illustrated below:
IIAR and Model Codes
While the importance of IIAR standards to ammonia refrigeration RAGAGEP has already been emphasized, the following code references provide evidence that IIAR standards have become “codified” by direct reference within every major model code:
2015 IFC §606.12.1.1 Ammonia refrigeration. Refrigeration systems using ammonia refrigerant and the buildings in which such systems are installed shall comply with IIAR-2 for system design and installation and IIAR-7 for operating procedures.
2015 NFPA 1 §53.1.3 Reference Codes and Standards. Refrigeration systems shall be in accordance with ASHRAE 15 and the mechanical code. Refrigeration systems using ammonia as a refrigerant shall also comply with ANSI/IIAR 2, Standard for Equipment, Design and Installation of Closed-Circuit Ammonia Mechanical Refrigerating Systems.
2015 UMC §1102.1 General. Refrigeration systems shall comply with this chapter and ASHRAE 15.
Exception: Ammonia refrigeration systems shall comply with IIAR 2, IIAR 3, and IIAR 5.
2015 IMC §1101.6 General. Refrigeration systems shall comply with the requirements of this code and, except as modified by this code, ASHRAE 15. Ammonia-refrigerating systems shall comply with this code and, except as modified by this code, ASHRAE 15 and IIAR 2.
NFPA 70-2017 §505.5 Refrigerant machinery rooms that contain ammonia refrigeration systems and are equipped with adequate mechanical ventilation that operates continuously or is initiated by a detection system at a concentration not exceeding 150 ppm shall be permitted to be classified as “unclassified” locations. Informational Note: For further information regarding classification and ventilation of areas involving closed-circuit ammonia refrigeration systems, see ANSI/ASHRAE 15-2013, Safety Standard for Refrigeration Systems, and ANSI/IIAR 2-2014, Standard for Safe Design of Closed-Circuit Ammonia Refrigeration Systems.
While it is acknowledged that the model codes do not uniformly reference the same IIAR standards, the reference to IIAR 2 in each model code once again emphasizes the importance of IIAR 2 to ammonia refrigeration RAGAGEP. The “trajectory” of the model codes has been to avoid adding new prescriptive ammonia refrigeration requirements and to simply reference IIAR standards for compliance.