20" Distribution and Valve Box (8 Hole,7 Hole, 6 Hole)

We have the solution to all of your onsite needs with our 20” Distribution Box! This box is great for large or small applications. No other box allows you to choose where to set your inlets or outlets. There’s no need to worry about different colored fittings or plugs to inventory because as well as accepting 2”, 3” & 4” pipe, our equal flow distribution boxes can also accept 6” pipe. Our 20” Distribution Box will also accept our 20” Risers so you can easily bring the box to grade. It is the most versatile Distribution Box available on the market today!


  • Easy to install.
  • Accepts risers to bring to grade.
  • Accepts 6", 4", 3" & 2" pipe.
  • Pipe can be installed at various heights.
NOTE: Not recommended for burial below 4 feet.

Part Number

  • 3017-206 (20" D-Box, 6 Hole with Flat Cover)
  • 3017-207 (20" D-Box, 7 Hole with Flat Cover)
  • 3017-20 (20" D-Box, 8 Hole with Flat Cover)

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Goes Well With


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Patent No# 5,154,353; 5,107,892; 5,680,989


Roto-Flow enables equal distribution to your leaching fields. Available in 3'' and 4'' sizes. The Roto-Flow gives you the low cost solution to your D-Box flow regulating problems. The simple Roto-Flow for D-Box outlet pipes gives you the easiest “set & forget” flow regulator available. The Roto-Flow fits both Schedule 40, SDR 35 and thin wall pipe sizes. Simply place the Roto-Flow into the D-Box outlet pipe, and adjust to equalize flow.

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Patent Pending


Polylok's dipper box guarantees uniform dosing for leaching systems. The Dipper is designed on the basic pivot and balance principle which insures equal distribution. The system works in unity instead of a ''trickle effect'' by providing equal flow distribution to each outlet. Polylok’s Dipper is easily installed in any septic system. Whether existing, new, reclining or flat — the action of the Dipper allows the entire system to work in unison. Insist on the DIPPER.

U.S. Patent No# 4,838,731

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20" x 6" Risers

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U.S. Patent No# 6,655,093; 6,688,072; 6,484,451; 6,877,28

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The best just got better. You asked for it and now we have it. Polylok is proud to introduce our 1 foot tall by 20" riser. It has the same high quality as our 6" tall by 20" risers, but with fewer screws that you and your customers have to put together.  Structural ribs inside prevent frost from adhering to the riser in frost prone areas.