Hoffman Specialty radiator traps reduce start-up times and improve overall efficiency. These radiator traps are small, simple in construction, and have the capacity for various applications, including in low-pressure heating systems. Balanced pressure radiator traps use a special bellows diaphragm. The diaphragm is designed to open in response to pressure and temperature to discharge air and condensate, and to close against passage of steam. The temperature at which a radiator trap opens varies.