Lap Joint Flange
Lap Joint flanges are also known in the industry as Backup flanges, Loose Ring flanges, Loose Hubbed flanges, and Van Stone flanges.
While distinct from structural Rolled Angle Rings, Lap Joint flanges are specifically engineered for pressure piping systems. They are the ideal choice for applications that require frequent dismantling for inspection or cleaning, as the design allows for rapid disassembly without cutting the pipe.
There are two standards to which Texas Flange offers a variety of stub ends to accompany our flanges. The MSS standard is the regular length stub end and the most commonly used in the flange industry. The ASA-type stub end is of a longer length and is less common than the MSS type, though it may be more suitable for your application. MSS Type A stub ends are the industry norm and are utilized with standard flat-face lap joint flanges.
While the hubs of Lap Joint flanges are typically longer than those of Slip On flanges, especially in larger sizes, they can be modified to meet your specific requirements.
When hub height is not critical, or if a 'True Lap Joint' is unavailable, we offer a solution known as 'Lap Joint to SO LTH' (Slip On Length Thru Hub). This consists of a Slip On flange machined with a lap joint face and ID radius. If strict adherence to ASME B16.5 length is required, please specify 'True Lap Joint' to ensure the parts are not manufactured from Slip On stock.
A key benefit of the Lap Joint design is that the flange itself does not contact the process media. This allows for significant cost savings by pairing a less expensive flange material with the required grade of stub end.
Lap Joint Flanges and Rolled Angle Rings
A Lap Joint flange serves as a backing ring in a two-part assembly, designed to slide over a Stub End which is butt-welded to the pipe. This allows the flange to rotate freely, simplifying bolt alignment during installation.
Unlike Rolled Angle Rings, which are typically used for tank stiffness or ducting, Lap Joint flanges are designed to B16.5 specifications to ensure pressure retention in critical piping operations.
Lap Joint Flanges
1) Lap joint flanges are a two-piece design with a backing flange and a rolled angle ring.
2) It is available in butt-weld and slip-on configurations.
3) Different materials are used for the backing flange and the rolled angle ring.
4) The backing flange allows for easier alignment because it is free to rotate.
Rolled Angle Rings
1) Rolled angle rings is a two-piece design with a rolled angle ring and a backing flange
2) It is available in butt-weld configuration.
3) Just like Lap joint flanges, different materials are used for the rolled angle ring and the backing flange
4) The backing flange is not free-to-rotate in roll angle rings compared to lap joint flanges.
Which Type of Fitting is Right for you?
Choosing the right flanges for your industrial application is crucial. It entirely depends on the requirement of the intended application.
Lap joint flanges are suitable for piping systems, allowing easy disassembly, while rolled angle rings are suitable for structural applications to create curved or rounded shapes within various structures; then a lap joint flange is an ideal choice.
Are you looking for something more rigid and challenging to disassemble? A rolled-angle ring is the best choice for you.
Frequently Asked Questions (FAQs)
The difference between a lap joint flange and a slip-on flange lies in their design and functionality. A lap joint flange consists of two parts: a stub end, which is welded to the pipe, and a loose backing flange that can rotate freely around it.
In contrast, a slip-on flange is a single-piece component that slides over the pipe and is welded in place, providing a simpler and more cost-effective connection. Slip-on flanges are commonly used in low-pressure applications where frequent dismantling is not required.
