Recent Blog Posts

Ammonia Week in Review | April 18, 2025

April 18th, 2025

Repeats and Fines in this week’s edition of the Ammonia Week in Review… Second Ammonia Leak in Six Years Forces Arena Shutdown in Port Alberni – This is the second time in six years that the chiller has suffered a “catastrophic failure,” according to city officials. […keep reading] Ammonia Leak Happens at Tyson Foods Poultry Plant – All workers […]

Relief Valve Replacement (Dual Assembly)

April 15th, 2025

This is an update to a blog that was originally posted on 3/10/15. You can read the original blog here. Question: Do both relief valves on a dual assembly have to be replaced every five (5) years, or just the relief valve that has been subject to system pressure? Answer: Most pressure vessels in an […]

Relief Valves Discharging Back into a Refrigeration System

March 18th, 2025

This is an update to a blog that was originally posted on 4/19/16. You can read the original blog here. ANSI/IIAR 2-2021 §15.3.10 outlines the requirements for providing Hydrostatic Overpressure Protection. In situations where thermal hydrostatic expansion of trapped liquid ammonia could occur, hydrostatic protection must be provided. Per ANSI/IIAR 2-2021 §15.3.10.1, Protection against overpressure […]

Ammonia Week in Review | April 5, 2019

April 5th, 2019

An ammonia mini bar causes a hotel evacuation in this week’s edition of the Ammonia Week in Review… Chester Grosvenor Hotel Evacuated after Reports of Ammonia Smell – Firefighters were called to the hotel on Eastgate Street in Chester shortly before 5am today (Wednesday, April 3) and crews, two wearing breathing apparatus, investigated where the smell was coming […]

Manufacturer Instructions and Ammonia Three-Way Relief Isolation Valves

May 29th, 2018

It is common practice in the ammonia refrigeration industry to install a three-way isolation valve upstream of relief valves protecting an ammonia refrigeration pressure vessel. For vessels larger than 10 ft3, this is required by most model codes and standards. These three-way valves allow a relief valve to be replaced without the hassle of pumping […]