The built-in Anti-Siphon Valve of AUTOAQUA Diaphragm Pump can resist the forward siphon pressure of 1 feet (30 cm) max. height from inlet water level to the outlet tube. If user wants to increase the anti-siphon pressure, please additionally purchase an AUTOAQUA Anti-Siphon Valve and connect it to the tube outlet to prevent forward siphon.

One Anti-Siphon Valve can stop around 2 feet (60 cm) of water of the forward siphon pressure.

● What is Forward Siphon ?

As inlet water level is higher than outlet tube, the water will be draw over continuously without pumping.

● AUTOAQUA Anti-Siphon Valve (Model : SV-100)

One Anti-Siphon Valve can stop around 2 feet (60 cm) of water of the forward siphon pressure.

If you need higher anti-siphon pressure, you can purchase AUTOAQUA Anti-Siphon Valve in addition.

Anti-Siphon Pressure Calculation:

*Please connects 2 pcs Anti-Siphon Valve in maximum on a water tube for proper water flow performance.

● Scenario 1 : Reservoir is higher than Tank/Sump

As Diaphragm Pump stops and water level of Reservoir is over 30 cm to the refill tube outlet, it might cause forward siphon (water keeps dripping into Tank/Sump).

Please follow below 4 methods to solve forward siphon :

1. Move the Reservoir lower
2. Move the Refill Tube Outlet higher
3. Please install AUTOAQUA Anti-Siphon Valve at the end of outlet tube to stop forward siphon.
4. If the water level of Reservoir is over 5 feet (150cm) to the refill outlet tube, please use a pin to puncture a hole on the inlet tube to break siphon.

● Scenario 2 : Waster Water Container is lower than Tank/Sump

As Diaphragm Pump stops and water level of Tank/Sump is over 30 cm to the drain tube outlet, it might cause forward siphon (water keeps dripping into Waster Water Container).

Please follow below 4 methods to solve forward siphon :

1. Move the Waste Water Container higher
2. Move the AWC Drain Tube Outlet higher
3. Please install AUTOAQUA Anti-Siphon Valve at the end of outlet tube to stop forward siphon.
4. If the water level of Tank/Sump is over 5 feet (150 cm) to the drain outlet tube, please use a pin to puncture a tiny hole on the inlet tube to break siphon.