Abstract: A valve for regulating the flow of fluid through an access port in a fluid chamber includes a body having a first end and a second end, the second end being located in the access port and the first end protruding outside of the access port. An axial bore extends from the first end to the second end, an injection fitting is formed at the first end of the body in fluid communication with the axial bore, and the second end of the body includes a selective sealing interface. The body forms a sealing interface with a threaded inner wall surface of the access port. A one-way valve assembly is positioned within the axial bore, and is arranged to permit a flow of fluid therethrough in a downstream direction and prevent the flow of fluid therethrough in an upstream direction. A bypass passageway extends from the selective sealing interface separate from the axial bore. A connecting passageway connects the bypass passageway with the axial bore upstream of the one-way valve assembly.