Brass flanges are usually made from a brass alloy, which is a combination of copper and zinc. Here are some common standard specifications for brass flanges:
Brass pipe flanges are available in a variety of sizes, typically 1/2″ to 12″ in diameter to suit the size of the pipe or valve. Pressure ratings for brass flanges include 150 PSI, 300 PSI, and 600 PSI, depending on the size and thickness of the flange.
Bronzeoilless.com Brass Flange Bushings are manufactured to various standards including ANSI, ASME, and DIN. Which specific standard a manufacturer follows depends on the intended use and customer requirements.