Norwesco 62787 4" bolted ball valve is precision molded in glass reinforced polypropylene, for strength and chemical resistance while also being light weight and easy to handle. It has an interlocking body and end plate to allow easy thread connection when installing valves. Teflon seats allow self aligning ball to rotate freely with low torque. Viton O-ring stem seal and EPDM O-ring body seal to handle most fertilizers and many chemicals.