| 摘要 |
A tubular casing 2 has a pipe connection 1 with a venting valve (not shown) which communicates with the vapour space of a container, for example, a bulk liquid transporter. The casing has two free ends 3, spaced from said pipe connection, each free end having a removable end cap 4, 4. A spring-loaded valve rod 5 extends between said caps, said rod having apertured closures 6 thereon which are capable of coacting with apertures 11 to seal the vapour space from the atmosphere under certain conditions e.g. connection of one end of said casing to the vapour space of another container by a compensation line 12 permits the valve rod 5 to move along the casing to allow closure 6 to seal apertures 11 and thereby to seal the vapour space of the first-mentioned container from the atmosphere. Pumping of liquid from one container to the other causes gases to pass from said other container to said one container instead of passing into and polluting the atmosphere. in a further embodiment, Figs. 3 & 4, (not shown), lift valves coact with seats provided in the casing. <IMAGE> |
