Forbes Marshall Bimetallic Steam Traps are thermostatic type of steam traps. Bimetallic steam traps work on the principle of bimetallic strip. A bimetallic strip comprises of two metals with different coefficients of thermal expansions joined together. As the hot condensate or steam enters the bimetallic trap, the two metals expand by different lengths. This bends the bimetallic strip and closes the trap port. Forbes Marshall Bimetallic Traps are robust and operate efficiently