What Are the Standard Sizes of Pipe Flanges?

You’ve probably seen pipe flanges before – those rimmed discs welded onto the ends of pipes. But did you know there are standard sizes for these important pipe fittings? Keep reading to learn about the common dimensions of pipe flanges.

Pipe Flanges Connect Pipes and Allow Access

As you may know, pipe flanges allow sections of pipe to be joined together. The two flanged ends are bolted together with a gasket in between to create a seal. Flanged connections make it easy to assemble piping systems and access the inside of pipes when needed. This is useful for maintenance, repairs, cleaning, and inspection. Flanges essentially act as sturdy removable caps on the ends of pipes.

The Many Pipe Flange Standards

There are quite a few standards that specify pipe flange sizes. Some of the most common are ANSI, ASME, DIN, BS, and JIS. For example, ANSI flanges are based on American National Standards Institute dimensions, while JIS flanges follow Japanese Industrial Standards. The standard used depends on where the pipes are manufactured and installed. Picking the right pipe flanges for an application means selecting the proper standard, pressure rating, diameter, bolt pattern, and facing type. With so many options, it can get confusing! But most systems only require a few common sizes.

The Typical Sizes Used in Systems

For many industrial water, steam, and gas systems, you’ll typically see flanges in sizes like 1/2″, 3/4″, 1″, 1-1/2″, 2″, 3″, 4″, 6″, 8″, 10″, 12″, 14″, 16″, 18″, 20″, 24″. Of course, larger pipe flanges are needed for bigger pipes, but those listed are some of the more common versions. You might notice those dimensions sound familiar – they correspond to standard pipe sizes. That’s because flanges are designed to fit the outside diameter of schedule 40 and 80 pipe. The flange size matches the pipe size, making installation straightforward.

Proper selection and installation are crucial for pressurized piping systems to operate safely. According to Forbes, there are more than 2.6 million miles of pipelines in the U.S. that safely deliver trillions of cubic feet of natural gas and hundreds of billions of tons of liquid petroleum products each year thanks in part to well-designed flanges. When you’re looking to purchase pipe flanges for the oil and gas industry, give us a call at Lynco Flange & Fitting today.

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