Flygt 4910, Flush Valve - MIDI Bobinage

Flygt 4910, Flush Valve (EN)Figure 18: After 30-40 secondsBefore first start:During the running-in period there is some risk that the valve will become clogged withsolid particles and sludge stirred up from the sediment on the bottom. In order to preventthis, it is recommended that the sump should be emptied and cleaned before the flushvalve is put to use.INSPECTION AND SERVICEOilInspectionMajor OverhaulThe flush valve 4910 is delivered with a rapeseed oil which is “environmentally friendly”.The freezing point of this oil is –30°C. Xylem recommends this oil because of itsenvironmental safety features. An alternative to this oil is to use a mineral oil in accordancewith ISO VG 32 (alternatively ISO VG-68, which will extend the flushing period comparedto the delivered oil).Note!An oil with a higher viscosity gives a longer flushing period and an oil with a lower viscositygives a shorter flushing period compared to the delivered oil.Regular inspection and preventive maintenace ensure more reliable operation. The flushvalve should be inspected when the pump is inspected. When the flush valve is taken outof the liquid for more than four days, the ball and the inner wall of the valve body shouldbe greased.The ball must be replaced if the inner diameter is less than 34 mm.Under normal operating conditions, the flush valve should be subjected to a majoroverhaul in a service workshop every third year.TROUBLESHOOTINGThe most frequent problem is that the inlet to the flush valve is clogged by a hard particle,too large for the valve throughlet.Providing that the flush valve is working within the limits, but does not close withinreasonable time, check the following:30 Flygt 4910, Flush Valve Installation, Care and Maintenance