Automatically stops the water supply to an RO system when the storage tank reaches full pressure. Reduces water waste and extends membrane life. No electricity required — operates on pressure differential. All 1/4″ quick-connect ports.

What it does

This auto shut-off valve (ASO) monitors the pressure in your RO storage tank. When the tank is full (pressure equalizes), the valve automatically closes and stops water from flowing through the membrane — no more continuous draining to waste while you’re not drawing water.

Installed between the RO membrane and the storage tank on the purified-water line, with a connection to the waste line. It operates entirely on pressure differential — no electricity, no batteries. When you open the faucet and tank pressure drops, the valve opens and the system resumes production.

Key benefits

• ✓Automatic shut-off — stops water supply when tank is full
• ✓Reduces water waste — no continuous drain when not in use
• ✓Extends membrane life — membrane rests when not needed
• ✓No electricity — operates on pressure differential
• ✓1/4″ QC ports — push-fit, tool-free installation
• ✓Compatible with most standard residential RO systems

Specifications

Compatibility

Often used with

Good to know before you buy

• Install between the membrane and storage tank on the purified water line. Also connect the waste line port.
• Confirm port orientation — inlet, tank, and waste ports must be connected correctly.
• Push 1/4″ tubing into each QC port until seated.
• After installation, verify the system shuts off when the tank is full and resumes when you draw water.