Abstract: A combination reheater isolation device and chemical connector is provided which is particularly adapted for use on lines leading to and from the reheater in a boiler-turbine plant system wherein the device can be used under normal system working conditions as a normal T-type fitting, wherein it can be modified to accept a chemical connector attachment for use in chemical cleaning and flushing and wherein the device also serves as an isolation device for hydrotest purposes. The device of the present invention employs relatively few parts and these are rugged and easy to assemble and disassemble.