Having a complete pipe flange description is crucial to getting the products you want correctly and on-time. As a flange manufacturer for over 50 years, we have seen many requests for quotation that were incomplete. Our favorite is, “I need a flange”. We strive to make what our customers need and to do that we need some specific information. Here is what we need to know:

1. The nominal pipe size the flange will be used with. ANSI B16.5 covers flanges dimensions for pipe from 1/2″ through 24″. B16.47 covers flange dimensions for pipe over 24″
2. The pressure class or the flange. This can be 125# light weight, 150#, 300#, 400#, 600#, 900#, 1500# or 2500#. Navy flanges have different pressure classes which can be 150#, 200#, 250# or 700#.
3. The gasket face is usually the next flange attribute we need to know. The most common are raised face, RF, and flat face, FF. Many other gasket facings are available such as ring type joint, RTJ, large and small male and female facing, large and small tongue and groove as well as others.
4. Next we need to know what style of flange will be used in your application. These include: weld necks – WN, slip-on – SO, socket welds – SW, blinds – BL, threaded – THD and lap joint – LJ.
5. Two styles of flanges, weld necks and socket welds, are machined to fit specific wall thicknesses of the nominal pipe we were told about in step 1. If you want to order weld necks or socket welds you will have to tell us what wall pipe they will be used with. Common wall thicknesses are standard – STD, extra heavy – XH, double extra heavy – XXH, schedule 10 – S/10, schedule 40 – S/40, schedule 80 – S/80 and schedule 160 – S/160. A complete pipe size guide can be downloaded here: https://pipingsuppliesinc.com/download-inquiry/.
6. One of the most important pieces of information is what dimensional specs the flanges are to be manufactured. This is sometimes omitted for commercial flanges and assumed to be ANSI B16.5. Navy specs include 810-4715319, MIL-F-20670 and DF361771. There are many other commercial and Navy flange specifications as well as international specifications like JIS and DIN.
7. Last, but certainly not least, is the metal you want the flanges made out of. A105 forged carbon steel may be the most common but there are also all of the stainless steels, aluminum, chrome molly grades, copper-nickel grades, and specialty metals like Monel, Inconel, Zirconium (yes, this is a real thing), and many others.
8. Not part of the description, but something that affects the price greatly, is the quantity needed for each flange item. This is usually noted before the actual flange description.

A typical flange description will have all of these elements and will look like:

120 – 2″ 600# RF SW S/80 B16.5 A182-F11

Yes, there is a lot more to flanges than most people think or want to know about. As flange manufacturing experts, we at Piping Supplies Inc want to make sure you get the correct items on time every time. To do that we need a complete pipe flange descriptions with all of the information above. If you have questions about flanges or any specifications, we would be happy to help. You can contact us at: https://pipingsuppliesinc.com/contact/.