| Patent Number |
Title Of Patent |
Date Issued |
| 5657527 |
Methods for making light-weight drainage line units |
August 19, 1997 |
| A method for manufacturing preassembled drainage line units comprises feeding a length of perforated vent pipe along a direction of manufacture longitudinally through a tubular mandrel, feeding a continuous sleeve of netting concentrically over the vent pipe along the direction of ma |
| 5639364 |
Light-weight drainage line units |
June 17, 1997 |
| A method for manufacturing preassembled drainage line units comprises feeding a length of perforated vent pipe along a direction of manufacture longitudinally through a tubular mandrel, feeding a continuous sleeve of netting concentrically over the vent pipe along the direction of ma |
| 5535499 |
Methods for making light-weight drainage line units |
July 16, 1996 |
| A method for manufacturing preassembled drainage line units comprises feeding a length of perforated vent pipe along a direction of manufacture longitudinally through a tubular mandrel, feeding a continuous sleeve of netting concentrically over the vent pipe along the direction of ma |
| 5378357 |
Light-weight drainage line unit employing end-to-end connectors |
January 3, 1995 |
| Preassembled drainage line units for a septic tank nitrification field employ a predetermined length of perforated conduit having an aggregation of discrete, crush resistant, light-weight elements surrounding the length of conduit and a perforated sleeve member enveloping the aggregation |
| 5154543 |
Method and apparatus for installation of drainage field |
October 13, 1992 |
| A preassembled unit for a sewage nitrification field has minimum outward dimensions of loose, lightweight plastic aggregate material enveloped and bound by a plastic sleeve around a horizontal conduit. In one embodiment, the unit takes a bag form with an aggregate-filled netting sleeve |
| 5051028 |
Method and apparatus for installation of drainage field |
September 24, 1991 |
| A preassembled unit for a sewage nitrification field has minimum outward dimensions of loose, lightweight plastic aggregate material enveloped and bound by a plastic sleeve around a horizontal conduit. In one embodiment, the unit takes a bag form with an aggregate-filled netting sleeve |
| 5015123 |
Method and apparatus for installation of drainage field |
May 14, 1991 |
| A preassembled unit for a sewage nitrification field has minimum outward dimensions of loose, lightweight plastic aggregate material enveloped and bound by a plastic sleeve around a horizontal conduit. In one embodiment, the unit takes a bag form with an aggregate-filled netting sleeve |
