In refrigeration systems, “Piping drives many problems.” That’s why the International Institute of Ammonia Refrigeration (IIAR) has published the Ammonia Refrigeration Piping Handbook, combining earlier published data with substantial input from contractor experts.
“Real expertise of piping lies with the contractor,” said co-author M. Kent Anderson. “A good refrigeration contractor knows piping well. Many things that go wrong with refrigeration systems can be traced back to the piping.”
The Ammonia Refrigeration Piping Handbook, introduced at the Refrigerating Engineers and Technicians Association’s (RETA’s) 91st-annual conference here, has close to 400 pages, 190-plus diagrams and drawings, 50-plus charts and tables, and 30-plus formulas (pressure drop, temperature drop, capacity, and more).
Coauthored by Anderson and Lane Bonebrake, it has been seven years in the making and contains a lifetime of refrigeration experience compiled from refrigeration contractors, sections of the ASHRAE Handbook and Standard 15, a long-used Vilter piping manual, and other sources. The Vilter manual is about 20 years old, the authors said. The ASHRAE Handbook has some piping information but not much, especially not for ammonia.
First of Its KindUp until now, there has been no comprehensive piping document, the authors said.
The resulting IIAR publication goes well beyond those source materials, especially in its use of contractor knowledge from the field, which is supported and enhanced by existing technological references; “taking what was published out there, and matching it up with real-world practices,” Anderson said.
The book includes:
The depth of information in one location has made this one of the most exciting new publications in the refrigeration industry in years, evidenced by the interest of RETA member technicians attending the session on the publication.
One of the book’s more controversial sections may be the one on pipe sizing.
Pipe SizingAccording to Anderson and Bonebrake, the new piping book’s development ran into some discord when the subject of pipe sizing was being tackled. In general, the publication leans toward larger pipe sizes than some refrigeration contractors may have been recommending for their customers. “You can cram any tonnage in any size pipe,” commented Anderson. “The option is in between” piping that’s oversized and piping that is undersized, but which has a lower first cost. The pipe sizing section includes:
For information on obtaining the book, contact IIAR at 1110 North Glebe Road, Suite 250, Arlington, VA 22201; 703-312-4200; 703-312-0065 (fax); email@example.com (e-mail); www.iiar.org (website).
Sidebar: Evaporator, Condenser Piping The evaporator section contains detailed piping recommendations for the installation of air-cooling units and liquid chillers; special-purpose evaporators; and piping and valve details (how it should be piped and valved to get the best performance).
The section also covers thermal expansion in liquid lock-up, and hydraulic shock, during which valves and headers can be fractured, pipes rupture, and more problems occur from the introduction of hot gas into a cold coil. The book describes how to deal with it, as well as the characteristics of flow.
“If pipes are clanging and banging, it isn’t working properly,” commented Anderson.
Also included is trapping and how to equalize flow between condensers.
Sidebar: Piping for Pressure Relief DevicesThis section includes:
Refrigeration System InsulationThis section goes beyond “just thickness; it addresses how to get a good vapor barrier.” Topics include:
Codes and Standards
Equipment Room PipingThis section includes:
Publication date: 11/13/2000