Prior to installing the 4-inch Lumo valve, the manifold should be modified using a Lumo-specific spacer.

The Lumo spacer matches the length of the assembled 4-inch valve (22.23 inches) and the inlet/outlet connections (4-inch Van Stone flanges). It’s watertight and can be pressurized when plumbed properly.

The Lumo valve should always be located on the outflow side of the manifold, downstream of any filters, manual (ball) valves, and pressure regulating valves.

To reduce turbulence and ensure accurate flow measurement, include at least 14 inches of straight pipe upstream of the Lumo valve (no elbows or T’s right before the valve) - equivalent to 3.5 times the diameter of the valve.

The 4-inch Lumo valve and spacer uses standard Van Stone flanges. When installing the spacer, use standard 4” washers for a watertight connection.

Each flange has 8 bolt holes. When tightening bolts, work in a star pattern to apply equal pressure across the flange (see drawing below for example). Use a torque wrench set to the torque specified on the pipe-end flange (typically 25 foot pounds for PVC Van Stone flanges).

If you don’t plan to pressurize the system before the valve is installed, bolts don’t need to be fully tightened.