ROOF Drain System
Articulated Rigid Pipe Type Roof Drain System
The pantograph type mechanical shoe seal is the most widely used design on external floating roof tank and provides long service life. The metallic band is formed as a series of shoes that are overlapped together to form a ring and held against the tank shell by pantograph type mechanical device. The counterweight assembly and arm exerts a constant pressure to push the shoe against the tank shell. The continuous seal covers the vapor space between the shoe and roof from the atmosphere.