We get this question a lot from customers who are often trying to determine if they should use malleable iron fitting or forged iron threaded fitting or socket weld fitting. Malleable iron fittings are lighter fittings in 150# and 300# pressure class. They are made for light industrial and plumbing use up to 300 psi. Some malleable fittings such as floor flange, lateral, street tee and bullhead tees are not commonly available in forged iron.
Malleable iron offers more ductility that is often required in light industrial use. Malleable iron pipe fitting is not good for welding (if you ever need to weld something to it).
See the table below for pressure and temperature rating of malleable iron fitting;
Malleable iron fittings, also called black iron fittings, are available up to 6 inch nominal pipe size, though they are more common to 4 inches. Malleable fittings include elbows, tees, couplings and floor flange etc. Floor flange is very popular to anchor items to the ground. Trupply sells wide variety of malleable iron fittings ONLINE that can be found here.
Forged Iron Pipe Fittings are available as socket weld pipe fitting or threaded pipe fitting. Forged fittings are made of A105 (carbon steel), stainless steel or nickel alloy. These fittings are thicker, heavier and are intended for heavy industrial use. Forged Iron Pipe Fittings are available in 2000#, 3000#, 6000# and 9000# pressure class. These fittings are more common in 3000# and 6000# (90% of the time). Threaded pipe fittings and socket weld pipe fittings are available up to 4 inch nominal pipe size. See the table below for pressure and temperature rating of these fittings.
Trupply sells these fittings for convenient online shopping here.
Video below gives an overview of malleable iron and threaded pipe fittings.
Malleable iron fitting
Threaded pipe fitting
socket weld fitting
Here is the cost comparison of different pipe fittings.
Malleable Iron Fitting - $
Threaded Pipe Fitting - $$$
Socket Weld Pipe Fitting - $$
Buttweld pipe fitting - $$
Forged Iron Threaded or Socket Weld Fittings are more expensive in sizes bigger than 2 inch compared to their malleable iron or butt weld counter parts.
Malleable Iron Fitting and Threaded Pipe Fitting differ in material metallurgy, pressure class and application . It is important to select appropriately between them for the intended application.
If you have any question about these fittings or want to buy one, call Trupply at 281.516.8100