Shutoff valve for fuel truck or tanker drain off downspouts

In a shutoff valve for fuel truck and tanker drain off downspouts, the combination including a base having a cylindrical tubular portion and an integral flange portion projecting radially outwardly from said tubular portion, said base including a valve seat located at the inner junction of said tubular portion with said flange portion, said tubular portion defining an outlet passageway communicating with said valve seat, means for connecting said tubular portion of said base to a downspout, a housing fixed to said base, said housing including a cylindrical peripheral wall and a top wall defining a chamber, said peripheral wall of said housing including a plurality of inlet openings communicating with said chamber, a ball valve disposed in said chamber and adapted to seat against said valve seat, means including a coil spring biasing said valve towards said valve seat, means including handle means for manually opening said valve, an adjustable stop member carried by said housing and engageable by said handle means whereby said valve is held away from said valve seat, and fusible means effective to disable said stop means in the event of a fire and permit said ball valve to engage said valve seat.