D-Plate Septic Tank/D-Box Adapter (Adapter Only) FREE SHIPPING


Septic-Direct’s 30″ x 36″ Fiberglass D-Plate Adapter allows you to connect any riser system (i.e. Tuf-Tite, Polylok, etc.) to a new or existing concrete D-Box.


Septic-Direct’s 30″ x 36″ Fiberglass D-Plate Adapter (Model DP3036) allows a new way to connect any riser system (i.e. Tuf-Tite, Polylok, etc.) to a new or existing concrete D-Box or Septic Tank.

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Made from durable composite fiberglass, the D-Plate is designed to withstand deflection caused by heavy soil loads.  The strength of the 1/4″ fiberglass D-Plate allows for the marriage of the larger diameter poly riser over top of the smaller opening of the square concrete d-box.

The D-Plate can also be used as an adapter for any riser system over a septic tank opening.  The D-Plate’s large 36″ x 30″ footprint provides coverage and security over any large septic tank opening that you are trying to gain access to with poly risers.

To install, apply sealant (i.e. Conseal Mastic, I/I sealant, Orenco ADH200, etc.) around the rim of the exposed concrete D-Box.  Fasten the D-Plate to the D-Box with concrete fastening screws (i.e. TapCons).  Fasten appropriate Adapter ring over the opening of the D-Plate with 5/16″ x 1″ self-tap screws and sealant.  Adapter Ring Models are listed below.  Use desired Risers and Lid to extend to grade.

Adapter Rings, Risers & Lid Models compatible with the D-Plate: pdf

Manufacturer                                Size                         Adapter Ring

Tuf-Tite                                             20″                           20-RTT

Tuf-tite                                             24″                            24-RTT

Polylok                                            20″                            3009-RTR20

Polylok                                            24″                            3009-RTR24

Polylok                                           24″                             3009-AR-C

Orenco                                           24″                               RRFTA24

EZSet                                              24″                               Adapter Flange

Sim/Tech                                       24″                              STF-AR2

D-Plate Brochure


Additional information

Weight 48 oz
Dimensions 36 × 30 × 1 in

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