STANDARD OPERATING INSTRUCTIONS NO. 2 MAINTENANCE AND OPERATION INSTRUCTIONS FOR POL FACILITI€S PARRY ISLAND DEHYDRATION OPERATION 8. The dehydrators are equipped with a water trap located in the sump. When the water level rises in the sump pilot operated motor valves No. V6 and V7 are closed, shutting the flow of the diesel oil. Pilot operated motor valves V91 and V92 open, and the water is drained from the sump through valves V90, V93, strainers S3 and $4, and motor valves V91 and V92 to a dry well. These motor valves are operated by a pilot attached to the water trap. When the excess water has been drained off, valves V6 and V7 open, the diesel oil resumes its flow, and the motor valves V1l4 and V15 close, shutting off the water drain, The sumps are equipped with an auxiliary drain and a gauge glass. Should the automatic equipment become inoperative, the water can be drained through this auxiliary drain by operating valves V94 and ¥95. The gasolone dehydration operation is the same as described above. See FS 497 for valve numbers. GLIANING OF DEHYDRATORS 9. The normal pressure drop through the dehydrators is 2 to 3 pounds, and filters should be changed if the drop exceeds 5 pounds. It is necessary to check the pressure drop at ten-day intervals, If new packing is required, a filter recommended or supplied by the manufacturer should be used.