The screw connection with sight glass is a spare part for the TOP SS and TOP VF series filter vessels, allowing the condition of the flushed water to be monitored directly at the valve without having to disconnect the hose. The transparent window immediately signals the transition from turbid to clean water during backwashing.
The part is designed for the operating pressures typical of sand filters with a top valve and is made of materials resistant to pool chemicals. The sight glass retains its clarity even after long-term operation in chlorinated water.
Replacing the cracked or clouded transparent section restores the ability to visually inspect the backwash. Proper monitoring of the backwash saves water and time by precisely determining the moment when flushing is complete.
