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When protecting your pressure instruments from harsh process conditions, isolators such as diaphragm seals or isolation rings are essential. They are designed to effectively protect pressure gauges, switches and transmitters from corrosive media, particulates, pulsations and extreme conditions. However, the effectiveness of these assemblies relies heavily on one important factor: proper filling. That’s where the challenge comes in. At Ashcroft, we’re often asked whether it’s acceptable to add fill fluid to a diaphragm seal or isolation ring in the field. On the surface, it may sound like a quick fix for a leaking or underfilled assembly. But in reality, attempting to add fluid outside of a controlled process may be problematic. Read this article to understand the science behind why isolator fills matter, why field filling may add risk and what you can do to keep your instruments reliable. By the time you finish reading, you’ll know why field filling is risky and the steps you can take to get accurate, safe readings that last for years.

Diaphragm seals, also known as isolators, are commonly used to help safeguard the wetted parts of pressure measurement instruments, such as sensors (transmitters and transducers), gauges and switches, from corrosive chemicals in your system's pipes. In some instances, however, diaphragms are also used to protect the instrument from large particles that could potentially obstruct the process connection. As a business development leader at Ashcroft – a leader in pressure instrumentation – I frequently address these concerns in low-pressure applications. Read this article to learn about the factors to consider for using a diaphragm seal in your operation and to use them on different types of instruments (mechanical or sensor) to keep your system flowing. You will also see additional resources you can use as a reference to deepen your knowledge of these isolating instruments.

This article was originally published on June 6, 2022, and was updated on March 5, 2025. In water and wastewater applications, corrosive substances or blockages from sludge or slurries can compromise your pressure and temperature instruments. How can you safeguard these instruments and maintain operational efficiency? A diaphragm seal offers protection, but not just any seal will suffice. You'll want a diaphragm seal with a flushing connection that can simplify the seal's cleaning process and prevent clogging. I've been working with Ashcroft - a leader in pressure and temperature instrumentation - for the better part of 33 years. Initially, I was the branch manager at an Ashcroft distributor, and for the past 10 years, I have been the Northwest territory manager. In both roles, I have helped customers understand the features and benefits of water and wastewater instrumentation. Read this article to learn what a flushing connection is, how it can help a diaphragm seal be more effective in harsh applications and when it's most advantageous to put one to work for you.

Isolation rings are very effective devices that protect pressure instruments from contaminant clogging and corrosion in several industries. However, there are certain circumstances where alternate methods of instrument isolation are recommended. As a global leader in pressure and temperature instrumentation, customers rely on the depth and breadth of our experience to educate and guide them through the process of finding the best solutions for their specific needs. In this article, you will learn why isolation rings are a good option for several very specific types of applications, but would not be recommended for others. As you read, look for links to resources that can help provide additional information to deepen your knowledge on this particular topic.

Pressure gauges, switches and transducers all have important roles in the safe and efficient operation of process piping, skid systems and other applications found in many industries. However, in certain scenarios, these sensitive instruments require protection from a range of challenging conditions, including extreme temperatures, potential clogging from particulates, or corrosive environments that could compromise their ability to function properly. To address these challenges the American Society of Mechanical Engineers (ASME) created industry standards and recommends strategies to protect instruments from damage in demanding applications. For example, ASME B40.100 recommends the use of isolation devices - widely recognized as diaphragm seals or isolation rings - as protective barriers that can ensure the longevity and accuracy of your pressure instruments. In this article, you will learn more about the three biggest challenges of these systems and the reasons to use a diaphragm seal or isolation ring. You will also learn about material traceability and certain certifications that may be required for these devices.

This article was originally published on April 24, 2023, and updated on October 23, 2024. Diaphragm seals and isolation rings are both integral to the safe and efficient operation of your application. Whether it is a chemical plant, water treatment plant or mining facility, these isolators are used throughout the plant to protect instrumentation from harsh process media. But what’s the difference between these two instruments? And, when would you use a diaphragm seal instead of an isolation ring? Throughout my career, I’ve heard this question a lot. Not just from the customers in my territory, but also from product distributors during any of the product training seminars that I conduct for Ashcroft. Continue reading to learn the basic differences between diaphragm seals and isolation rings, which you would use one over the other in specific applications and why. You will also see links to additional resources to learn more.