| 摘要 |
A container 1 has a thermoplastic body 2 and a neck 3 incorporating a pressure relief valve 7, 30-33, wherein the neck is to be fitted with a closure 4 to retain pressurised contents within the container. The container may be a keg suitable for beer, made from stretch blow moulding (SBM), and the pressure relief valve (PRV) may be contained within the wall thickness of the neck to release gases on the occurrence of an over-pressure event. The PRV may comprise a bursting element 21 (fig 3), which renders the container unusable, or a spring-loaded seal 30 which re-seals after the release of excess pressure. The valve may vent gas between the closure and the neck of the container, and it may be permanently changed to an open condition by removal of the cap, preventing re-use of the container. |
