ASCO is the leader in the design and manufacturing of quality solenoid valves, from around the corner or around the world. ASCO combines over 100 years of leading edge experience with technology, innovative engineering and commitment.........bringing or customers, the highest level of performance, dependability and support. You cannot go through a day without being impacted by one of our valves. While a doctor uses ASCO's micro miniature solenoid valves to keep saline flowing to a patient's eye during microsurgery, the world's largest refineries are using ASCO pilot valves to regulate and control the flow of oil and gas.