First, let us clarify a common point of confusion. The specific handbook people search for is often referred to as , titled "IIAR 2: American National Standard for Safe Design of Closed-Circuit Ammonia Refrigeration Systems." However, the "Piping Handbook" moniker comes from the document’s in-depth focus on pipe sizing, material selection, pressure ratings, and layout.

If you design, install, or inspect ammonia piping more than once a year, purchasing the legitimate from IIAR is not an expense—it is an investment. One avoidable pipe failure can cost hundreds of thousands in cleanup, medical claims, and regulatory fines. The handbook’s tables alone can save you engineering hours that far exceed the $250 price.

| Service | Minimum Velocity (fps) | Maximum Velocity (fps) | Reason | | :--- | :--- | :--- | :--- | | Suction Lines | 10 (horizontal) | 4,000 (vertical) | Oil return in horizontal runs | | Discharge Lines | N/A | 5,000 | Noise & pressure drop | | Liquid Lines (non-pumped) | 1.5 | 3.0 | Preventing flash gas | | Pumped Liquid Lines | 3.0 | 7.0 | Maintaining NPSH |

The actual handbook provides 20+ pages of charts adjusting these numbers for pipe diameter, temperature, and refrigerant quality.

: View the current IIAR Publications Catalog for pricing and technical details on the 2019 edition. Reference and Educational Materials OSHA Technical Reference : A detailed Table of Contents and Technical Summary