The 683B intelligent exhaust throttle valve integrates all control, communication, and driver circuits via a compact “add-on” electronics module onto an MKS Type 253 throttle valve assembly, thereby eliminating the need for mounting a separate pressure control electronics module. The second generation PID control algorithm can be tuned to drive the system to set point fast and with minimum overshoot, and ensures repeatable process recipes without operator involvement. The loop tuning parameters are completely adjustable to accommodate variations in system parameters.
The Type 683 Throttle Valve operates in two modes: flapper positioning or pressure control, either of which can be user-activated through the network communications interface. All of the adjustable setup parameters, run time operation, and diagnostics information is available through the network communications interface. The Type 683 also includes adjustable soft-start functions for set point changes to minimize turbulence and thus particle distribution in the chamber. Two alarm relay outputs are fully adjustable to trip at specified pressure, valve position or set point deviation settings. The Type 683 is designed to be compatible with MKS Digital Baratron® Capacitance Manometers to offer all of the components required to perform closed-loop pressure control over the network. Alternately, the Type 683 will accept a 0-10 VDC signal from a traditional analog Baratron Capacitance Manometer for closed-loop control.
This downstream pressure control technique provides wide dynamic range, works with all types of pumps, provides fast response, and is tolerant to most effluent gases.
The 683B communicates using DeviceNet™, a high performance communication link based on a broadcast-oriented protocol called Controller Area Network (CAN). The DeviceNet protocol, is easy to install and provides a simple and economical way for instruments and controllers to be interoperable on a network. The “intelligent instrument” concept results in valuable system space savings, improved noise immunity, and easy access to time-critical process and calibration information as well as on-board diagnostic functions. System design, installation, maintenance, and labor costs are reduced as compared to the traditional analog I/O.
The Type 683 is based on the field-proven Type 253 valve, a direct-drive design with no belts to wear or slip, thereby improving performance. The valve driver includes a unique cosine generator placed between the flapper shaft and the motor drive shaft which generates a more linear valve transfer characteristic and provides high resolution pressure control. The robust, high torque motor provides extended uptime and reduces preventative maintenance cycles — a great advantage in demanding processes where just one hour of downtime can cost thousands of dollars.
The valve is constructed of corrosion-resistant 316 stainless steel for the toughest process gases and is available in standard ISO-KF and MF flange styles with bore sizes from ¾” to 4” (20-100 mm). Consult factory for availability of additional flange styles. Standard seals offered are Viton®, alternate materials can be specified for compatibility with various process chemistries.