Sierra Series 830/840/860 Side-Trak™ and ... - Sierra Instruments

Chapter 4 MaintenanceSeries 830/840/860 Instruction ManualValve MaintenanceElectromagnetic valves may require spring-tension adjustments forvarious reasons (See Valve Adjust Procedure). No maintenance isrequired under normal operating conditions other than an occasionalcleaning. Use of certain corrosive gases may require frequentreplacement of the valve plug and O-rings. This indicates aneed for a different elastomer. Viton is standard, with Neoprene,Kal-Rez (or equivalent), and PFA Teflon offered as options.Do not attempt any valve adjustments while the meter is “on-line”with any dangerous gas. All controllers should be thoroughly leaktestedfollowing any valve adjustment.For the Model 860 Auto-Trak, refer to “Piston Tube CalibrationProcedure” for instructions on how to re-adjust the electromagneticvalve for proper operation.Electromagnetic Valves - Low and Medium Flow ControllersControllers with a low or medium flow body use the same valve;high flow models use a larger version. Cleaning can often be accomplishedby opening the valve, using the purge function andflushing in both directions. Alternatively, the valve may be manuallyopened by loosening the 6-32 lock nut on top of the valve andturning the adjustment screw fully counterclockwise.To disassemble the low and medium flow valve for inspection:Caution!When using toxic or corrosivegases, purge theunit thoroughly with inertdry gas before disconnectingfrom the gas line.1. Remove the unit from the system.2. Remove the two 4-40 Phillips head screws on top of the enclosure.Remove the enclosure by sliding it up and off. Removethe metal cap on top of the valve by inserting a flat tip screwdriverinto the slots provided and prying upward.3. Use a 5/8 inch nut driver to loosen and remove the 5/8 inchnut at the top of the valve. Remove the coil, coil enclosure andwarp washer.4-8 IM-83/84/86-H