Threaded flanges are probably the most recognisable of all flanges due to their screw thread design that is used to connect it to the pipe.
Threaded flanges, also known as screwed flanges (for obvious reasons), require a male and female thread to create a connection and, in turn, a tight seal.
Typically, we see these particular ring-type joints in smaller piping systems – those less than 4 inches – and systems that are non-toxic, low pressure, and involve only low temperature.
We explore the threaded pipe flange further in this post, providing the benefits and disadvantages so you can weigh up which RTJs are best for your application and piping system.
Threaded Pipe Flange
Threaded flanges are fittings that are used in piping systems with internal threads.
They are a good choice when welding is not an option, due to the environment in which you’re operating in.
Male and female threads are required to connect the flange to the pipe fitting in question, where the male thread is cut into the pipe, and the female thread is cut into the bore of the flange.
Installation requires the tapered screw inside the flange to be mounted onto the pipe – matching the threads perfectly, as the manufacturer then screws the threaded pipe into the pipe threaded flange creating the seal.
When we say that the flange thread must match perfectly, we mean that it must have the same thread specification as the thread inside the pipe in order to create a seal that doesn’t leak.
This ring-type joint gasket is available in various sizes and a range of pressure ratings; however, the most common sizes we find are between ½ inches and 2 inches.
It’s important to note that in some instances, a weld seal will still be required to provide a secure connection.
Ring Type Joints
A threaded flange comes as a raised or flat surface:
Raised face threaded flange – compatible with a wide range of gaskets from metallic to semi-metallic types and as either ring or full. Raised flanges help to increase seal strength between the two mating surfaces of the connection by manipulating the concentration of the pressure.
RTJ threaded flange – To support a ring joint gasket, a circular groove is manufactured into the RTJ flange, making it more suitable for high-pressure and high-temperature applications. This type of gasket is chosen when metal-to-metal seals are required.
Benefits of a threaded flange
The most significant advantage of opting for a threaded flange is that these gaskets can be connected to a pipe without the need for welding. In some instances and industry environments, this can be essential. For example, these types of flanges are an ideal solution for piping systems in petrol stations or applications where flammables are located.
These flanges are also quicker and safer to assemble and disassemble compared to their counterparts, making them a popular choice for industrial applications.
Providing a reliable and leak-resistant joint that requires no welding, it offers quick maintenance and modifications without the need for specialist equipment.
Ideal for:
- Plumbing applications and pipework
- HVAC systems
- Oil and gas applications
- Chemical industry
- Food manufacturing
- Connecting pipes to pumps, valves, pressure vessels, tanks
- And more.
We recommend that these flanges be used in highly explosive areas and hazardous applications where welding is not an option.
They’re also economical, save time during installation, and are suitable for piping applications with a small internal diameter.
Disadvantages of a threaded flange
Due to their makeup, these types of flanges are not suitable for high-temperature applications. If placed in such situations, they would distort easily and quickly, leading to leaks.
Threaded flanges are not suitable for pipes with a thin wall thickness, as they increase the risk of cracking and splitting around the connection.
In addition, if the threads are misaligned or beginning to wear, the connection will be prone to leaking and susceptible to further damage.
This makes these flanges unsuitable for hazardous systems and not suitable for all industries.
Ring Type Joint Gaskets
We provide a wide range of gaskets and flanges in various shapes, sizes, and material grades suitable for multiple applications and piping systems across various industry sectors.
Our threaded flanges, in particular, are both cost-effective and time-effective due to their ease of use and design specification. They are also incredibly reliable in applications where extreme pressure is present.
To help, our team is on hand to provide you with the answers to your questions, offering you the most suitable product and sealing solution for your application.
Put us to the test.
Email your requirements to sales@specialistsealingproducts.co.uk and see how we can help you further.
