In this article, I will explain the basic principles of Postweld Heat Treatment (PWHT), why it is used in the fabrication of pressure vessels, and how to use this information in pressure vessel inspections.  The rules for PWHT are found in the ASME pressure vessel code, and I caution you that this article is basic information and in no way comprehensive .  If you have a question about a particular vessel, seek advice from the original manufacturer or a repair/alteration organ

Last week, we shared a breakdown of the U.S. Chemical Safety Board’s (CSB) final report on the hazardous ammonia release at Cuisine...

The Chemical Safety Board (CSB) recently released its final report on the hazardous ammonia release at Cuisine Solutions, a food...

Graduating in May 2025, I found myself wondering what industry my first engineering job would be in and whether I would even enjoy it...

At Macha PSM, we work with facilities across the country to help them manage process safety for ammonia refrigeration systems. While much...

A site map is a scaled drawing that shows the layout of a facility. It includes buildings, process areas, storage locations, and access...

Are refrigeration materials of construction interchangeable?  Can you replace carbon steel that is installed in an area prone to...

Lockout/Tagout/Tryout (LOTOTO) is a critical safety practice, especially in ammonia refrigeration systems, to prevent accidental release...

A block flow diagram (BFD) is a high-level process diagram used to represent the major steps in a chemical or industrial process. As the...

[This is three of three in a "Now What?" blog series by Chris Foster, a Macha PSM Consultant] If you missed our previous instalment of...

I’m only 19 years old. I’ve been in the PSM and ammonia refrigeration industry for about a year and a half. In that short time, I’ve...

When we think of inspecting pipe supports , we go immediately to damage or deterioration, and we should.  Far less often do we consider...

[DISCLAIMER: This blog series is not a comprehensive Safety Data Sheet. You MUST refer to the appropriate SDS for your facility’s Ammonia...

[DISCLAIMER: This blog series is not a comprehensive Safety Data Sheet. You MUST refer to the appropriate SDS for your facility’s Ammonia...

[DISCLAIMER: This blog series is not a comprehensive Safety Data Sheet. You MUST refer to the appropriate SDS for your facility’s Ammonia...

If your facility uses an ammonia refrigeration system—no matter the size—you’ve got a major deadline coming fast. Under ANSI/IIAR 9-2020,...

From 3” binders of information sitting on a shelf to digitized forms living in the cloud, I have seen a lot of changes over 33 years in...

On May 5th, I graduated with my degree in Chemical Engineering. One week later, I began working full-time as a process safety engineer at...

Macha PSM Acquires Guideline Training – Taking Our Impact to the Next Level We are proud to announce that Macha PSM has officially...

[DISCLAIMER: This blog series is not a comprehensive Safety Data Sheet. You MUST refer to the appropriate SDS for your facility’s Ammonia...