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THE ROTORK GEARS MOW RANGE OF MODULATING WORM GEAR VALVE ACTUATORS Rotork gears has extended the range of applications of their worm gearboxes with a design for modulating duties. The modulating operators are available to suit valves or dampers requiring multi-turn or part-turn inputs. The design employs the principles developed for the well established IW range of gearboxes. Particular design features include grease lubrication, a ground and polished worm shaft and an aluminium bronze wormwheel. The advantages of the standard range have been retained. Notably, the output sleeve is easily removable for machining to customer requirements. All gearing is totally enclosed and sealed for life within the gearcase. Operating temperature ranges from -20oC to +120oC. Other temperature ranges are available on request. Gearboxes can be manufactured to a wide range of environmental specifications, including low and high temperatures, submersible, buried service, marinised and AWWA. Exeeco modulating gear operators are designed for use on valves or dampers requiring constant movement. They are suitable for continuous duty of 1200 starts per hour and give a positional accuracy of ± ½ o. The MOW range has been designed with customer stocking in mind and has a removable steel drive sleeve to facilitate bore and keyway machining. This separate drive sleeve can be positioned through 90 o steps in the MOW3 to MOW8 and 45o steps In the MOW9 to MOW11. The basic standard units are grease filled for life, sealed to IP67, and finished with grey primer. The mechanical stops are adjustable at 90o ± 5o travel. The baseplate has the facility for positioning through 45o steps on the MOW3 to MOW5 and 22½o steps on the MOW6 to MOW11, thereby catering for on or off centre mounting on the valve stool without special machining. Standard input and output flanges are to ISO 5211/1 standard. However, equivalent standards eg DIN and ANSI can be supplied MATERIAL SPECIFICATION Gearcase Cast Iron to BS1452 grade 250 (MOW3 to MOW8) SNG Iron to BS2789 grade 420/12 (MOW9 to MOW11) Baseplate Cast Iron to BS1452 grade 250 End Cap Cast Iron to BS1452 grade 250 or Steel to BS970 grade 070M20 Actuator Flange Cast Iron to BS1452 grade 250 Indicator Plate Steel to BS970 grade 070M20 Wormwheel Aluminium Bronze to BS1400 grade AB2 Wormshaft Steel to BS970 grade 045M10 O Rings Synthetic Rubber Fixing Screws HT Steel metric standard BS3692 and BS4168 Worm Shaft Bearings Angular Contact Ball Bearings Output Sleeve Steel to BS970 grade 070M20 (MOW3 to MOW5) Steel to BS970 grade 080M40 (MOW6 to MOW9) Steel to BS970 grade 070M55 (MOW10 to MOW11) Grease Renolit LST 0 Due to Rotork gears policy of continuing improvement, the Company reserves the right to change specification details without prior notice. Design life For modulating duty torque ratings of gearboxes are based on a minimum maintenance free life of two years or 17,520 hours continuous operation. Life tests These are based on two years continuous operation at an average of one third modulating torque. The test is accelerated by limiting operation to 30o at output and using the load versus time relationship of BS721. The test duty cycle is 50% (1½ seconds on, 1½ seconds off) with 1200 starts per hour. Positional accuracy is maintained at ±0.5%. ISSUE 2 14.11.00 SW d:\265331700.doc