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.
KF (QF) Flanges. KF flanges (Figure 1) are a sexless designâmade from 304L or 316L stainless, aluminum, or brass. The seal is a rubber/ elastomeric o-ring mounted in a centering ring, which aligns the flanges and holds the o-ring in position.