Abstract: A pipe joint assembly joins two double wall pipe sections together. The pipe joint assembly includes a first pipe section having at least one double wall corrugation on an end portion, a second pipe section having at least one double wall corrugation on an end portion and a joint formed by locating the first pipe section end portion and the second pipe section end portion in an overlapping relationship. The pipe joint assembly substantially increases the strength of the joint relative to conventional pipe assemblies.

Abstract: An improved barrel extruder for extracting oil from seeds and other vegetable matter comprises a barrel screw that extends a substantial distance from the barrel downstream end and substantially through an extractor head. The extractor head is divided into three sections comprising a screen section and a port section where oil is extracted under extreme pressure and a tip section where the pulp is forced through a narrow gap to provide back pressure to the pulp in the port section. Under the extreme pressure developed in the port section, a substantial portion of the oil content of the oil seed or vegetable matter is extracted from the pulp. The extractor head is configured to permit the screen section and port section and separately the tip section to be easily exchanged for oil seeds and vegetable matter with different pulping characteristics and oil volume or percentage content.