What is the difference between threaded and flange valves?

Threaded valves attach directly to threaded pipe ends, whereas flange valves are connected to the pipes by bolting flanges together with a gasket between them.

Furthermore, their distinctions go deeper than that, such as in terms of their advantages and lifespan.

As a leading manufacturer of industrial valves, we know the importance of choosing the right valve for optimal system performance, and we can help you better understand these types.

Hence, continue reading because this article will explain how to distinguish between threaded and flange valves. 

Flange Valve vs. Threaded Valve: Differences in Valve Flange Connection 

The flange valve had round, flat discs on both ends, with a central opening and bolt holes around it.

They are bolted to the matching pipe flange, with a gasket between them to provide an effective seal and no leaks.

Threaded valves, on the other hand, commonly connect their internal screw threads (female threads) to the pipe’s external screw threads (male threads).

Threaded valves might feature external screw threads that link to the internal screw threads on the pipes.

Threaded Valves vs. Flanged Valves: Long-Term Valve Life and Aging Characteristics

Flanged connections often have a longer lifespan because their gasket and bolts, with proper maintenance, can maintain durable seals even when temperature and vibrations change.

Furthermore, their bolted connections limit the possibility of sliding damage to pipe and valve threads or galling, making them less prone to thread wear.

Threaded valves may have a shorter lifespan because their connections are vulnerable to deformation, corrosion, or galling, which can cause leaks.

Moreover, flange valves tend to be easier to maintain because you may unbolt and retighten them without damaging the pipe connections.

Threaded valves are difficult to maintain because continuous removal and reinstallation can damage the threads, increasing the need for repairs or replacement.

Flange Valve vs. NPT Valve Connection Type: Effect of Vibration and Changing Forces on Connection Integrity

Flange Valve

Flange valves’ gasket and bolting make them generally offer higher stability and be able to handle vibration or forces from changing motion.

This made these valves more ideal for industries that have large pipes and frequent operation with high pressures, including: 

• Oil and Gas
• Chemical processing
• Water & Wastewater Treatment

The bolt also helps spread stresses across the flange, but studies like that of Huaguang Ni et al. report that repeated stress or vibrations can still cause damage to them.

Fortunately, CLDG offers the Forged Integral Flanged End Valve to further prevent damage caused by those mentioned issues, such as leaks!

Here are some of the advanced features:

• High Pressure Class Ratings (150 LB to 2500 LB)
• The flange is part of the valve body itself, reducing possible wear and tear on joints.
• And much more.

NPT Valve (National Pipe Taper)

NPT valve is one of the most common threaded connection types.

The pipes and NPT valve threads fit tightly, allowing them to hold together strongly and withstand vibrations from systems.

Furthermore, these valves in smaller sizes can often tolerate higher pressures of 100-10000 psi.

However, when under intense or frequent vibrations, the force is focused on their threaded parts, causing them to experience galling, and eventually leak, as compared to flange valves.

Therefore, their reliance on tapered threads that may loosen due to rotational vibration makes them best suited for smaller pipes and low-vibration applications only like:

• Residential and Commercial Plumbing
• HVAC (Heating, Ventilation, and Air Conditioning)

Flange End Valve And Threaded Valve: In A Nutshell

If you want a more reliable and durable valve for a demanding working environment, flange valves are more suitable due to their unique connection type.

Threaded valves, on the other hand, are great only for simpler applications.

CLDG is a global valve manufacturer with decades of expertise, designing and producing solutions to meet diverse client requirements worldwide.
Contact us now to speak with our engineers and get more details on how we can assist you in your business!