Manhole for tank body or tank lorry used for transporting e.g. liquid products, has sealing devices defining hermitically sealed annular chamber between annular and peripheral flanges when tightening unit connects flanges

摘要

The manhole has a shell comprising an opening surrounded by an annular flange (9), and a cover surrounded by a peripheral flange (13). A tightening unit connects the flanges so as to hermetically seal the opening. Sealing devices (17, 18) assure sealing between the peripheral and annular flanges. One of the devices is spaced radially from the other device. The devices define a hermitically sealed annular chamber (19) between the annular and peripheral flanges when the tightening unit connects the flanges. A measuring unit i.e. manometer, measures the pressure in the chamber. An independent claim is also included for a method for verifying sealing of manhole of a tank or tank vehicle.