Abstract: A drain valve assembly for draining fluid from a container, for example an engine crankcase, is constructed with a first threaded bolt portion having external threads for engaging in a threaded drain outlet of the container and internal threads in an axial passage passing through the first threaded bolt portion, a second threaded bolt portion having external and internal threads whereby, use, the external threads engage in the internal threads of the first threaded bolt portion to seal therewith and whereby passages extend through the first and second bolt portions to permit flow of fluid therethrough. A sealing member forms part of the second threaded bolt portion whereby on full insertion of the second threaded bolt portion in a first position within the first threaded bolt portion, the sealing member engages an adjacent surface to prevent the escape of fluid from the container and, on retraction to a second position, the flow of fluid through the first and second threaded bolt portions is permitted.