VESSELS WITH PERSONNEL ACCESS PROVISIONS

摘要

A vessel for pref. high-purity and ultra-high-purity gasses has a shell (14), a sleeve (18) mounted on the shell making a passage (20) for gaining personnel access to the interior of the shell, and a cover (22) for covering the passage. The sleeve can be located within the interior of the shell.The cover is permanently connected to the sleeve pref. by a. weld (44). The cover has a skirt (28) and a projection (24) defining a groove where the weld is located. A valve (35) can be mounted on the cover or one or more valve boxes having valves can be mounted at other locations on the shell. The vessel can be partitioned. For gaining access to the vessel the weld (44) is cut and cover (22) is removed by lowering it into the vessel pref. by using a lifting strap.