National Pipe Thread (NPT) and National Pipe Straight (NPS) are standards denoting the type of threads used on pipes, but they differ in their design and usage.
What’s NPS threads?
NPS, which stands for National Pipe Straight, is used to refer to straight threads on pipes ranging from 1/8 inch to 12 inches in nominal size. These threads are engineered to form a secure connection when the pipes are joined together. However, they are not meant for high-pressure applications due to their straight design.
What’s NPT threads?
On the other hand, NPT, standing for National Pipe Taper, is used for taper threads on pipes ranging from 1/16 inch to 24 inches in nominal size. Unlike NPS threads, NPT threads are crafted to create a tight seal, making them a common choice for plumbing and hydraulic systems. They are also suitable for low-pressure applications like air compressors and pneumatic tools, thanks to their tapered design which enhances the sealing capability.
What’s The Difference?
When comparing NPS and NPT, even though they can engage with each other, they do not seal properly when interconnected. The core difference lies in the fact that NPT threads are tapered while NPS threads are straight. Despite this difference, both NPS and NPT threads share the same thread angle, shape, and pitch (threads per inch), with a 60° included angle and flat peaks and valleys in their design.
This distinction in design makes NPT more suitable for applications requiring a tight seal, while NPS is more suited for other types of connections where high pressure is not a concern.
Hydraxio manufactures and supply stainless steel NPS and NPT fittings, please feel free to contact us for more details.
