Table of content
Introduction
Knowing the difference between G pipe thread and NPT is very important for its use. So what are the specific differences between the two? This article mainly introduces the differences between the two in terms of use, shape, characteristics, etc. If you need to know about these two accessories, then you are welcome to read the following article.
What is NPT (National Pipe Thread)?
NPT thread is mainly one of the American standards. The appearance shape of this accessory is conical, which can make the connection more secure without the need for additional accessories when tightening.
Features of NPT Threads:
Shape: The conical design does not require additional accessories when used, which can make the connection more secure.
Use: Mostly used for water pipes and gas pipes.
Compatibility: The conical design is less compatible and is not suitable for other shapes of connectors.
What is G Pipe Thread?
G pipe thread is also commonly called BSPP, which is a British standard. The connection of this thread is flat. Additional accessories such as gaskets are required when connecting. Adding washers can make the connection tighter.
Features of G Threads:
Shape: The connection is a flat design. Sealing: Adding a gasket can make the connection tight.
Application: Mostly used for low-pressure water treatment pipelines or low-pressure gas pipelines.
Differences Between G Pipe Thread and NPT Thread
Although both are connectors, there are some minor differences due to their different design shapes.
| Feature | NPT (National Pipe Thread) | G Pipe Thread (BSPP) |
| Thread Type | Tapered (conical) | Straight (parallel) |
| Sealing
|
Self-sealing, no external seal needed | Requires an external seal (e.g. o ring) |
| Angle | 60° angle | 55° angle |
| Common Applications
|
High-pressure systems, gas lines,plumbing | Water systems, low-pressure fittings |
| Compatibility | Incompatible with G threads and other types | Incompatible with NPT, but compatible with BSPP |
Are NPT and G Threads Compatible?
The two are incompatible. Mainly because of the different shapes. NPT threads are tapered and usually 60 degrees. G threads are flat and mostly 55 degrees. These two connections are prone to loose connections and leakage from the surface products.
Applications of NPT and G Threads
NPT Thread Applications:
Gas pipeline: NPT threads have high sealing properties and can withstand high pressure. So they can be used for gas pipeline connections.
Hydraulic system: NPT threads are commonly used in high-pressure hydraulic systems
Pipeline: NPT threads are used in pipeline systems that require reliable, self-sealing connections.
G Pipe Thread Applications:
Water treatment system: G threads are usually used in low-pressure water systems, and O-rings can be added when connecting to maintain the seal.
Industrial system: Low-pressure industrial pipe connections.
Low-pressure fittings: G threads are very suitable for systems that do not involve high pressure.
How to Identify NPT vs G Threads?
The main difference between the two is to look at the shape of the two. There are 4 more specific ways:
1. Angle measurement: NPT threads have a 60° angle, while G threads have a 55° angle.
2. Taper: NPT threads are tapered. G threads are straight.
3. Visual inspection: NPT threads generally have a flatter appearance compared to the rounded profile of G threads.
4. Pitch: NPT threads generally have a higher pitch (tighter threads), while G threads have a wider pitch.
Conclusion
Both NPT and G threads are important accessories for connecting pipe systems. The main difference between the two is the different shapes, resulting in different connection methods. NTP is mainly used for high pressure and does not require additional accessories. G thread is mainly used for low pressure systems and requires gaskets. And both are incompatible.
So understand the difference between the two. I hope it can be helpful for you in making a choice.
