A flange is a plate-like device used to construct a piping system; it connects pipes, pumps, valves, and other gadgets. Flanges are typically screwed on or welded. The slip-on flange is generally used in the petrochemical industry.

Principle of a Flange
A flange works to maintain the seal created between the flanges and gasket. It uses the force exerted by the bolts to counteract the internal pressure when there is sufficient contact stress. Welding, threading or weldless connections couple the flange to the pipe.

Hygiene
Standard attachment of slip-on flanges is unacceptable for hygienic applications. Product can accumulate in the space between the two internal-fillet welds. This makes cleaning and sterilization difficult.

High-Pressure Environments
Slip-on flanges are unsuitable for high pressure or high-temperature uses, because of poor strength at the joint. They do not handle extreme conditions, despite some flexibility with metal expansion and contraction.