The Difference Between ISO and NPT Fittings

Across all industries and sectors, a lot is riding on a fluid system’s high-pressure fittings. Often, these fittings play a vital role in keeping your process or fluid system safe; routine maintenance, repair, and replacement are critical to your operation’s success.

When the time comes to replace your high-pressure fittings, it is critical to ensure you have the right parts for the job. Two of the most common specifications in Canada for high-pressure fittings are ISO and NPT threads. Although they appear similar, the two standards are wholly incompatible in high-pressure applications. Read on to learn more about the difference between ISO and NPT threads, as well as Hy-Lok’s extensive inventory of high-pressure fittings.

ISO vs. NPT Threads

ISO threads are identical to British Standard Pipe Threads. Although they may appear identical to NPT threads in size and dimension, they feature a slightly different pitch (distance between threads).

Why does this matter? Especially in high-pressure applications, variances in thread pitch often result in an improper seal, leading to a compromised connection, leaks, and ultimately safety hazards for your personnel and equipment.

Generally speaking, ISO-compatible fittings can be found on equipment manufactured around the world, whereas NPT fittings are usually only found in North America. With the wide variety of equipment found in Canada, it is imperative to know what types of fitting your fluid system needs and ensure any new or replacement parts are compatible.

High-Pressure Fittings at Hy-Lok

“Close enough” is very rarely good enough, especially in high-pressure applications. No matter the industry or operating conditions, every fluid system needs precision-built parts that are fully compliant with all specifications and regulations, not to mention compatible with your existing components. Your fitting supplier should be able to provide fittings that precisely meet the needs of your next project.

Hy-Lok’s extensive inventory is one of the largest in North America. We offer a comprehensive range of fittings suitable for all high-pressure applications, including systems using both ISO and NPT threads. No matter what your system needs, Hy-Lok is dedicated to getting our customers the parts they need, when they need them.

Seamless integration is integral to any operation’s productivity. That’s why Hy-Lok Canada’s fittings are designed to be 100% interchangeable with Bi-Lok, S-Lok, Swagelok, and other manufacturers’ components. Hy-Lok tube fittings can be intermixed in all sizes and applications while providing equal or superior performance to our competition’s products. Our high-pressure fittings will integrate into your fluid system without added strains and costs typically associated with intermixing components, such as retraining installers or offloading existing inventory.

Coast-to-Coast Service

Reliable access is just as important as reliable parts. If your operation is committed to efficiency, you need a fitting supplier equally committed to quickly fulfilling your orders. Prolonged wait times will end up costing your business time and money, preventing you from maximizing your productivity and meeting your goals.

Hy-Lok’s nationwide network of representatives and distributors is committed to finding you the right components and processes for your operation. With expedited shipping and inventory management services available, Hy-Lok Canada is committed to providing value-adding solutions from start to finish.

Looking for High-Pressure Fittings?

Contact us today to learn about Hy-Lok Canada’s complete catalogue of fittings and accessories.