If a spacer was plumbed in prior to the valve installation, loosen all bolts on the spacer and remove from manifold

Position the fully assembled wetware between the Van Stone flanges fixed to the inlet and outlet pipe ends

Ensure that the flow of water matches the directional arrows on the valve body

Rotate the valve to the desired orientation

Ensure that the washers are centered between the flanges

Insert all bolts and hand tighten

Tighten bolts 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)