Gate valves from Asahi/America can be used for on/off service and for throttling. Their nonrising stem design provides a larger seating area than conventional gate valves. The seating area, which runs 360 degrees around the cylindrical plug, also virtually eliminates valve chatter. When fully open, they allow straight-through flow, which minimizes pressure drop. Available in sizes 1.5 through 14 inches, valve bodies are high-impact PVC with polypropylene gates and EPDM seals and can be electrically actuated up to 3 inches. Options include a 2-inch operating nut, stem extensions, locking handles and FKM seals. They are rated for full vacuum service and are NSF 61 certified. 800-343-3618; www.asahi-america.com.