This series is intended to bring attention to failures in the “coded welding” practices. From not using certified welders, to failures in visual and NDE, and failures in Pressure/Leak testing. This first incident was caused by a decision NOT to perform Post-Weld Heat Treatment on a repaired pressure vessel…. Membership Required You must be a...
While virtually any liquid trapped in a “blocked-in” section of pipe can cause a rupture due to thermal expansion, specific chemicals are strictly regulated by OSHA 1910.119 (PSM) and NFPA 30 because of their volatility or toxicity. The requirement for a hydrostatic relief valve (HRV) is generally triggered by the chemical’s physical state (liquefied under…...
This is not the first time I have addressed this matter. Still, somehow, somewhere, a dirty little lie has been circulating among ammonia design and installation contractors that somehow an engine room handling less than 10,000 pounds of anhydrous ammonia (NH3) is incapable of presenting an explosion hazard, thus no need for any engineered ventilation. …...
I am sure this article will ruffle a few feathers, but honestly, I am surprised and disappointed by that. But I do a lot of work in flammable liquid processing, and this topic always comes up during audits, PHAs, and accident investigations. Some folks will swear that only grounding is “required.” They get this from…...
Imagine taking a snowball and rolling it down the side of Mount Everest. As the ball rolls down the mountain, it gets bigger and faster. If we can stop it early in its travel down the mountain, BEFORE it gets to BIG and FAST, we can save the town at the base of the moutain…....
Generating static electricity in flammable liquids involves charge separation that occurs whenever the liquid moves relative to a surface. The process follows a specific sequence:… Membership Required You must be a member to access this content.View Membership LevelsAlready a member? Log in here...
In the world of flammable liquids processing, we have two (2) types of flammable liquids: Members can read all my articles on how these flammable liquids get classified as “conductive” vs. “non-conductive. This post is to explain HOW and WHY the traditional “bonding and grounding” used in the transfer of flammable liquids may be inadequate…...
Before an employee enters the space, the internal atmosphere shall be tested, with a calibrated direct-reading instrument, for oxygen content, for flammable gases and vapors, and for potential toxic air contaminants, in that order. We test for oxygen before testing for flammability (LEL) for two (2) critical reasons: Here is the breakdown of why this…...
The rule—”Add Acid to Water” (AA)—is one of the most important safety practices in a chemistry lab. It all comes down to how much energy is released when they mix and how the liquid behaves as a result. Let’s explore the science behind this safety rule together. I’ll ask guiding questions along the way…. Membership...
The frequency for testing or replacing hydrostatic relief valves (HRVs) depends largely on the service environment, the fluid being handled, and the specific regulatory standards like OSHA, NFPA, CGA, or ASME governing your process. Because these valves are designed to protect against thermal expansion in liquid-filled lines—often in “blocked-in” sections—their reliability is critical to preventing…...
If we are making a final “tie-in” weld between two segments of pipe that have already been independently pressure tested, that specific weld can be exempt from a final system pressure test if:… Membership Required You must be a member to access this content.View Membership LevelsAlready a member? Log in here...
In the realm of process safety, a Functional Test of the Safety Instrumented System (SIS) is a periodic procedure performed to ensure that an SIS will operate as designed when a real-world demand occurs. While a system might look operational on a control panel, internal “hidden” failures could prevent it from actually shutting down a…...
