Abstract: A valve assembly used to minimize chemical loss during the transfer of chemicals from one container to another is disclosed herein. The valve assembly minimizes chlorine or other process material loss to the environment by sealing the manifold and the cylinder to be filled from the environment while the valve assembly is connected or disconnected. The valve assembly includes an inlet valve connectable to an outlet valve, the inlet valve comprising a first plug positioned in a bore extending between an inlet and outlet port and a transfer tube engaging a bore of a first insert positionable within the bore of the inlet valve. The outlet valve comprises a second plug positioned in a bore extending between an inlet and outlet port and second insert positionable within the bore of the outlet valve. The transfer tube has a first and second end configured to be insertable at least partially within respective bores of the first and second inserts, the first and second ends each having at least one port.