Abstract: A dual-wall fitting includes an outer fitting member and a fitting insert. The fitting insert may be slideably placed within the outer fitting member. The outer fitting member has an inner surface and a channel surface. The inner surface defines an upper channel and the channel surface defines a first leakage channel that extends from an exterior of the outer fitting member to the upper channel. The fitting insert has an outer insert surface that defines a groove. When the fitting insert is slideably placed within the outer fitting member, the inner surface of the outer fitting member and the groove defined by the fitting insert define a second leakage channel. The first leakage channel is in fluid communication with the second leakage channel.