Hi I have just fitted a ballofix vavle and filled up with no leaks as i was tiding up ~I notice a direction arrow on the ballofix vavle, i thought you could fit them anyway round...does it matter as i really dont want to drain down and turn the vavle round if i dont have to..its only a 15mm vavlue that you turn on and off with a screw driver...does it matter!!