Flange Plugs

 Among the category of flange fittings (or flange adapters) are flanges plugs, which are used to cap off or block the flow in the pipe. Flange plugs are basically a flange without a center hole which closes the end of a pipe when bolted to a standard mating flange. Depending on the system requirements, these plugs are typically gas or liquid tight. For gray water subsurface irrigation they are sometimes used to force waste through perforated holes in the pipe, driven by system pressure.

Flange Fittings & How They Fit In

The fluid power industry is making a shift to connections with an elastomeric O-ring seal, to minimize leakage. These fittings include the SAE straight thread, face seal, ISO 6149, SAE  J518 (Code 61 and Code 62) flange fittings and flanges (Code 61 and Code 62), where the O-ring seal is compatible with the fluid.

 Not Interchangeable

 It is important to note that the two flange fitting style codes (61 and 62) are not interchangeable due to their pressure ranges and their different bolt patterns. As shown in this diagram of overlapping code 61 and code 62 4-bolt flange fittings, the dimensional placement of holes are close, but not identical. Note the difference in the bolt-hole’s center-to-center dimensions.

Benefits of Flanges

 Though there are specific applications where flanges and/or flange fittings are the only practical choice (particularly in larger, high pressure piping applications), flanges sometimes provide benefits to the piping system that traditional hydraulic fittings do not. For instance, in those larger OD applications flanges are often able to be connected to pipe (tube or hose) and component ports more easily than threaded fittings or adapters. Most importantly, in many severe service applications on mobile construction equipment flanged connections are best for: