Flange design is only the start when considering the ideal flange for your piping system. Face types are another characteristic that will have a major impact on the final performance and service life of your flanges.
Facing types determine both the gaskets needed to install the flange and characteristics related to the seal created.
Common face types include:
Many face types also offer one of two finishes: serrated or smooth.
Choosing between the options is important as they will determine the optimal gasket for a reliable seal.
In general, smooth faces work best with metallic gaskets while serrated faces help to create stronger seals with soft material gaskets.
Apart from the functional design of a flange, flange dimensions are the most likely factor to impact flange choices when designing, maintaining, or updating a piping system.
However, you must consider how the flange interfaces with the pipe and the gaskets in use to ensure proper sizing.
Common considerations include:
Each of the above characteristics will have an influence on how the flange performs across a range of processes and environments.
So how can you tell which flanges are up to the task and which are not?
Flanges are often classified based on their ability to withstand temperatures and pressures.
This is designated using a number and either the “#”, “lb”, or “class” suffix. These suffixes are interchangeable but will differ based on the region or vendor.
Common classifications include:
Exact pressure and temperature tolerances will vary by materials used, flange design, and flange size. The only constant is that in all cases, pressure ratings decrease as temperatures rise.
To help make comparison easier, flanges fall under global standards established by the American Society of Mechanical Engineers (ASME) -- ASME B16.5 & B16.47.
If you’re attempting to replace or verify existing parts, all flanges must include markers -- typically on their outer perimeter -- to aid in the process.
These markers also follow a strict order:
This guide offers a solid foundation of the basics of flange design and how to choose the ideal flange for your piping system. However, with a wide range of stainless steel flanges and other flange materials available, it is impossible to list every configuration, detail, or consideration.
Should you have questions, the Technical Sales Experts at Unified Alloys are ready to help. Serving industries and businesses across North America and Canada for more than 40 years, we understand the complexities of alloy piping and the needs of your industry. Call us today for additional information and to find the ideal flange, piping, and components for your next project.