Tack Fia.
Hittade lite mer om sandfilter.
"How do I Backwash my Sand Filter"
When the pressure gauge is reading 8-10 lbs above the clean, starting pressure (after backwashing), it is time to backwash the filter.
This process involves turning a valve so that the water will flow through the filter backwards, flushing out the dirt. Hence the name back-washing. Sand filters can have either a push-pull valve (aka slide valve) or a multiport valve. The multiport valve has multi- ports on the valve, usually 6 positions:
FILTER: Keep it here 99%, except when backwashing, rinsing or wasting
RINSE: Use this setting for 20 seconds after backwashing to rinse tank
RECIRCULATE: Use this if the filter's broken; at least you're circulating.
BACKWASH: Use this setting to reverse the flow in the filter and send water out of the waste line. Make sure valves are open or hoses rolled out
CLOSED: Put here to close off flow from the pool, usually to work on the equipment. Do not operate pump with valve in closed position
WASTE/DRAIN: Another filter bypass setting, but this one sends the water out of the waste pipe (hose), instead of returning it to the pool. Used to lower pool water level or to vacuum to waste
So, to backwash a sand filter with a multiport valve;
Shut off pump motor
Press down on valve handle, rotate valve from FILTER to BACKWASH position
Roll out any backwash hose or open any waste line valves
Open air bleeder assembly on filter, and turn pump on.
Watch pressure gauge for backpressure and hose for kinks. Be prepared to shut off pump quickly
After hose fills with water, run for 2-3 minutes or until water runs clear
Shut off pump motor and move multiport valve handle to RINSE position Run on rinse for 15-25 seconds.
Shut off pump motor and move multiport valve handle to FILTER position
Turn pump back on and note lower pressure. Roll up backwash hose
Källa:
http://www.poolcenter.com/filter.htm//Janne
