ET bulletin调节阀资料.pdf

Product Bulletin 51.1:ET August 2002 ET Valve Design ET, EAT, and ETR Sliding-Stem Control Valves Design ET, EAT, and ETR general-purpose control valves (figures 1, 2, 3, and 4) are used for throttling or on-off control of a wide variety of liquids and gases. All three valve designs have single ports, balanced valve plugs, and cage guiding. Metal-to-PTFE seating for stringent shutoff requirements is standard in all valves except those with Cavitrol III cages. Metal-to-metal seating for higher temperatures is standard for valves with Cavitrol III cages and optional for all other valves. The temperature limits of Design ET valves can be extended above 232C (450F) by using PEEK (PolyEtherEtherKetone) anti-extrusion rings in combination with a spring-loaded PTFE seal. The PEEK anti-extrusion rings expand to close off the clearance gap between the plug and the cage where the PTFE seal may extrude at high temperatures and pressures. The temperature limits are extended to 316C (600F) for non-oxidizing service and to 260C (500F) for oxidizing service. The easy-e Valve Family Design ET, EAT, and ETR control valves are part of the versatile easy-e family of industrial control valves from Fisher. easy-e valves share the following characteristics: Multiple trim material choices Interchangeable, restricted-capacity trims and full-sized trims to match variable process flow demands Different cage/plug styles that provide particular flow characteristics for highly-specialized W1916-3 / IL applications. The standard cage comes in three different flow characteristics: quick-opening, linear, or equal percentage. Figure 1. Design ET Control Valve with Type 667 Actuator