A slip-on flange can also be known as a hubbed flange, which, as the name suggests, has a hub with a very low profile.
Why is this important?
Because this type of ring type joint gasket has an internal diameter larger than the connecting pipe, allowing you to slide it onto the pipe with ease and speed.
Sliding over the pipe, these types of RTJs can be directly connected to the equipment or pipe in question using a fillet weld in two locations on the flange.
This particular type of flange is typically found in low-pressure, medium-temperature piping systems.
To learn more about this flange and fillet welding type, read on.
Slip on Flange Welding
Hubbed flanges can be connected to pipes with one or, in some instances, two fillet welds (one outside the flange and the other inside). This is, of course, dependent on the
application and the specifications of the piping system.
However, it’s important to be aware that because there is no full penetration weld (unlike the counterpart weld neck flanges), their use is limited as they offer lower weld integrity.
(Make sure to also check out our post on `Threaded Flanges` to find out the advantages and disadvantages and how these compare to slip on flanges.)
Slip-on flanges are also available in various sizes, making them suitable for a range of pipe diameters. And this type of ring type joint is ideal for low pressure applications and great if you’re limited on space.
Slip-on flanges in higher-pressure classes are often made with the height of a lap joint, allowing you to achieve a better connection.
However, if the hub height is not a concern, and you don’t need a specific lap joint, you can opt for a slip-on flange made to a lap joint style with a machined hub.
Two varying slip on flange types which have mechanical differences include:
- Welding flange plate
- Welding flange – hubbed steel pipe
Face types include:
Raised face slip-on flange – this type of flange sees a slight protrusion of the seal at the bottom, which is designed for gasket placement during installation. During installation, the benefit of this extrusion is that it allows for a gasket set to be inserted, enhancing and providing exceptional sealing performance. In addition, as pressure ratings increase, the raised face height will also increase, continuing to provide a secure seal – enforcing the seal.
RTJ slip-on flange – this type of flange requires a small precision groove to be expertly engineered on the face element of the flange. The groove created is then used to insert the gasket ring required for sealing. This particular type of slip-on flange then allows this type of flange to be suitable (short-term) for high-pressure applications due to its superior sealing ability.
Benefits of slip-on flanges
A simple and excellent alternative when looking for a quick sealing solution, slip on flanges offer:
- Low procurement costs
- Easy installation and disassembly
- No weld preparation requirements
- A great alternative if you’re limited on space
- An integral ingredient to pipe connections
- Looping systems
- A simple structure
- A convenient process
- Cost-effective solutions
Disadvantages of a slip-on flange
- You may need to use two welds to secure instead of just one
- It has a reduced mechanical strength compared to weld neck flanges
- It is not suitable for cyclic loading
- Generally not used above ASME class 600
- Durability life is one-third of a weld neck flange
Installation
Slip on flanges, slip over the pipe, where you will then align the bolt holes appropriately, followed by inserting the bolts and tightening to the correct torque levels.
Ring Type Joints
There are numerous requirements that still must be met for the installation, maintenance, and testing of these flanges – and this is where the experts at Specialist Sealing Products come in.
Used in various fluid applications to connect equipment, slip-on flanges offer low installation costs, are easy to align with other parts, and can provide a better seal in low-pressure applications.
However, we know that it’s vital to consider a range of factors and understand all of the advantages and disadvantages of a range of flanges before choosing the right one for your piping system.
Let us help.
With years of experience and expertise with various gaskets, seals, flanges, and more, we know what works with specific applications and what can provide you with the best sealing solution around.
Put us to the test.
Speak to a member of our team today about your specific requirements.
If you would like any further information on our slip-on flanges, please call 01535 274 776 or email us at sales@specialistsealingproducts.co.uk.
