Recent Blog Posts

Relief Valves Discharging Back into a Refrigeration System

April 19th, 2016

ANSI/IIAR 2-2014 §15.6 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 2-2014 §15.6.1, Protection against overpressure due to thermal hydrostatic expansion of trapped liquid ammonia shall be provided for equipment and piping sections that can be […]

Remote Emergency Stop Switches (E-Stops)

March 21st, 2016

Remote Emergency Stop Switches are an integral part of a compliant ammonia refrigeration machinery room. ANSI/IIAR 2-2014 §6.12.1 requires that: “A clearly identified emergency shut-off switch with a tamper-resistant cover shall be located outside and adjacent to the designated principal machinery room door. The switch shall provide off-only control of refrigerant compressors, refrigerant pumps, and normally […]

Principles of Refrigeration

February 22nd, 2016

In order to properly identify and control hazards in an ammonia refrigeration system, it is necessary to understand how a refrigeration system operates. Without understanding the basic principles, one is likely to be confused, slow to respond, or even incorrect when identifying unsafe conditions. What is refrigeration? Refrigeration is a process wherein the pressure of […]

Vessel Nameplate Removal

December 8th, 2015

I recently received an email from a client asking if it is allowable to remove a pressure vessel nameplate and position it in another location on that same vessel. Here is the response that I gave: Dear John, Unfortunately, ASME National Board does not allow nameplates to be removed unless approved by an inspector and an updated […]

Manufacturer Data Reports

September 28th, 2015

When performing Compliance Audits and Mechanical Integrity inspections, I often find facilities do not have Manufacturer Data Report as required for a compliant PSM program. What is a Data Report? Often referred to as the “birth certificate” of a pressure vessel or heat exchanger, the data report (U-1 or U-1A, U-3 form) is a document […]