Chemical Process Safety (PSM/RMP)

One of the acceptable “protection techniques” for electrical enclosures within a Hazardous Location is to “pressurize the enclosure.”  Here are the three (3) Types of Pressurized Enclosures and the HAZLOC they are permitted to be used, and their design basis: NFPA 70, 500.7, (D) Purged and Pressurized. This protection technique shall be permitted for equipment in…...

In process safety, we spend a lot of time discussing the PRIMARY containment systems; however, our secondary containment systems play a vital role in our PROTECTION and MITIGATION layers of protection. Of course, we want to keep the tiger in its cage, but we also need to be prepared for the day it gets loose,…...

When we encounter a manufacturing facility that has been pulled into OSHA’s PSM or EPA’s RMP, we are almost certain to find the same design features for the emergency stop functions (i.e., E-Stops). Most of these facilities are shocked to learn there is a big difference between the location of an E-Stop on a machine…...

I believe in Excess Flow Valves and Check Valves, even though I have seen them fail more often than work as hoped. However, these failures are “human failures” in the incorrect design (e.g., sizing and placement) of the process where these valves are utilized. The valves are highly reliable when they are DESIGNED, INSTALLED, and…...

Some Excess Flow Valves (EXFVs) models can be placed into a position that would render them useless in their intended function. I have encountered this scenario more than once during my PHAs, Investigations, Audits, etc. There are not many manufacturers that incorporate this failure mode in their designs, but there a couple that do; and…...

What prevents excess flow valves from closing when the line breaks?  There are plenty of things that can prevent EFVs from operating as designed.  These include design failures, mechanical failures due to poor or no maintenance, and “human failures.” 1. Not a Clean Break For one or a combination of the following reasons, excess flow…...

I am aware that NFPA 58 applies to LPG installations; however, with the “dumbing-down” of many RAGAGEPs, I am always looking for the BEST DESIGN for my process safety functions. I do wish the IFC would define/quantify where remote activation stations must be, as they did decades ago. But for now, I use NFPA 58,…...

Hose failures during the unloading/loading of HAZMATS are still causing many problems for far too many businesses.  We have discussed the process side and the DOT container site engineering requirement for when the hose fails.  This post is a list of requirements that we should be incorporating into our HAZMAT safety programs regarding the use…...

Another pressurized piping fatality… On March 27, 2024 @ 9:30 a.m. Employee #1, 21, had been installing hydronic piping in a boiler room. Employee #1 began loosening a clamp holding a pressure testing cap that was under 100 PSI of pressure. The testing cap became a projectile, striking Employee #1 in the face. Employee #1…...

According to reports, the sewage explosion occurred during a pressure test of the septic tank pipeline conducted by qualified engineers as part of the pipeline installation process. This incident should be all we need to demonstrate why we test before the pressure retaining equipment is put into service and NEVER use hazardous materials to perform…...

An ammonia leak occurred inside the machinery room of a public athletic club with indoor ice facilities. The leak happened during the decommissioning work of an ammonia refrigeration condenser by a licensed refrigeration contractor, which resulted in the facility enacting its Ammonia Release Emergency Protocol. The incident was likely caused by the contractor not properly…...