Abstract: A piston type valve including a valve body having a horizontally disposed fluid flow passageway with an inlet at one end of the passageway and an outlet at the other end of the passageway. A valve piston is mounted in the body for selective vertical movement to and away from the passageway inlet and outlet to selectively close and open the passageway and control fluid flow therethrough. A debris holding tank is disposed on the valve body below the fluid flow passageway and is in fluid flow communication therewith. The passageway outlet has its bottom portion disposed higher than the bottom portion of the inlet whereby debris contained in the fluid flow through the passageway strikes the outlet bottom portion and falls into the tank. The valve piston is cylindrical and is mounted on vertical guide rods to guide the piston in its vertical movement and to prevent it from turning in a horizontal plane.