Coke drum bottom unheading system

Abstract

Clamping system and method for clamping the bottom head cover of a coke drum to the bottom flange thereof are disclosed. The system and method include determining the flange stiffness or resistance to deflection resulting from the spring-like force exerted on the bottom head cover and bottom flange gasket seating surface by the gasket in its compressed state. This deflection information may then be used to estimate the minimum number of clamps needed to ensure sufficient load remains on the gasket at the midpoints between the clamps to effectively keep the gasket sealed. An appropriate number of clamps may then be disposed around the periphery of the bottom flange to clamp it to the bottom head cover. In one practical design, each clamp engages a lug attached to the periphery of the bottom head cover such that the clamp does not extend underneath the bottom head cover when clamped.