Install the Valves, Filter, Pressure Regulator and Valve Box
- The valves, filter and pressure regulator are typically located inside a valve box which is usually placed near the backflow preventer.
- Do not put too many valves in one valve box. Two valves per box are recommended. Leave enough room in each valve box to allow yourself to work comfortably with the valves and wires and to easily remove and replace the filter later on during routine maintenance.
- For aesthetic and practical reasons, it is better to place valve boxes below ground, making the top of each valve box about two inches above grade (this will put valve boxes at ground level after the top dressing has been installed).
- After determining the best place for the valve box, dig out the area adequately so that the top of the valve box will rest at grade (it will be raised above grade later on during the installation process).
- Because the system will experience higher pressure before the valve, schedule 40 PVC pipe should be used between a PVB or RP backflow preventer assembly and the valve.
- After the control valves are installed, attach a filter and a pressure regulator to each one.
- Wrap a small amount of Teflon tape around all threaded fittings to help lubricate and seal them. Make sure all fittings are good and tight.
- Now it is time to place the box over the valves. You may have to cut additional holes in the sides of each box to allow for proper location of the pipe/poly tubing.
- Place bricks or blocks strategically under the edges of each box to provide stability. This should raise your box two inches above grade.
- Be sure the box is level; then replace soil around the outside edges of the box. Cover excess openings around pipes with fabric or tape to keep soil from entering the box.
- Fill the bottom of each valve box with one to two inches of gravel to promote drainage and to avoid muddy conditions inside the box.