Tight shutoff at any pressure.
High-performance fluid applications requiring tight shutoff at full-rated ANSI pressures, such as cooling-water lines in air conditioners, aircraft fuel lines, or oil refinery pipelines, are the potential uses for the K-LOK 310/312 Butterfly Valve, designed by Keystone Valve USA Inc., a division of Keystone International Inc. in Houston.
The K-LOK is equipped with a heavy-duty circular key that holds the reinforced polytetrafluorethylene (PTFE) valve seat and carbon steel retaining ring in place. The setup provides bidirectional, dead-end service at full-rated pressure while eliminating the need for retaining screws, which can corrode easily and are difficult to remove after exposure to surface conditions. K-LOK's uninterrupted gasket surfaces also allow the use of standard spiral-wound gaskets. When the K-LOK is throttling, its 316 stainless-steel disc is cammed away from the seat, reducing wear and deformation.
The K-LOK's interference seat design has an energized elastomer O-ring, so the valve can be shut off tightly at lower pressures. The stem packing consists of force-dried, soft-braided PTFE rings and molded PTFE V rings to provide a tight seal. Press-fit steel or stainless steel bearings are located near the valve disc to minimize deflection. The carbon steel or stainless steel body of the K-LOK features an extended neck that allows for two inches of insulation and integral-cast travel stop.
K-LOK is available in both wafer or lugged styles, and its seat O-ring comes in a variety of materials for different applications. Original equipment manufacturer Gas Packagers Inc. in Denver incorporated the K-LOK in the gas compression systems it built for Natural Gas Pipeline m Lombard, Ohio, ARCO in Alaska, and Conoco in Texas.