The parts of the flush bottom valve are identical to that of a globe valve and the closing and opening actions are also similar. The shut off is achieved by disk closing against the body seat. The disks in closed position match with the bottom of the vessel or piping leaving no room for hold up or stagnation.

Normally, the inlet size of a standard flush bottom valve is one size higher than that of the outlet size. There are special constructions possible with both sizes same. The outlet port is at an angle to the inlet port. Normally 45 or 60 degrees deviation is provided.