Small animals tend to live shorter lives than larger animals. There are a few theories as to why that is, but the one I believe is most popular is: small animals tend to live shorter lives anyway (because of threats from predators), so there are fewer opportunities to evolve to be long-lived.
The American National Standards Institute (ANSI) Class 150 is a system of dimensional standards for weld neck, threaded, slip-on, lap joint, socket weld and blind flanges. Dimensions for facing, bolts and studs are also included in ANSI Class 150. ANSI Class 150 establishes measures for pipe sizes.
A flange is a method of connecting pipes , valves , pumps and other equipment to form a piping system .It also provides easy access for cleaning , inspection or modification . Flanges are usually welded or screwed .Flanges joints are made by bolting together two flanges with a gasket between them to provide a seal.