Attributes . Crouse-Hinds series explosionproof unions are installed in rigid/IMC conduit systems to connect conduit to conduit, a conduit fitting, junction box or device enclosure. Expansion unions are also available, which allow for expansion and contraction of conduit and compensate for conduit cut too short. Available in a variety of materials, including stainless steel, to suit customer preferences. Explosionproof elbows allow for a 90° change in direction to the conduit run, or when terminating at a box or fit . Names