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316 Stainless Steel Sewer OB's

Derwent Industries 316 Stainless Steel Sewer OB’s are Australian manufactured. Sewer OB’s are a permanent sewer branch connection and can also be used for repairs on Non-Pressure Sewer pipelines. Manufactured in accordance with AS4181and the new WSAA specifications.

Technical Data Sewer OB:


Size Range:                               DN100 – DN 450

Offtake Sizes:                           DN 100 / 150 / 225 
                                                   (Offtake size is dependent on host pipe)


Temperature Range:                -10°C to 60°C

Max. Operating Pressure:       100 kPa

Quality Assurance:                  ISO9001:2015

Certificate Number:                QEC2004

WSAA Certification:                 PA 1917              

Please refer to your local water authority for schedule of approved products.




  • 316 Stainless Steel for Superior Corrosion Protection

  • Bolts and Nuts coated with molybond to prevent galling.

  • Sewer OB's provide a simple and permanent connection whilst supporting the integrity of the main.

  • Nitrile Gasket providing a full circle seal.

  • Sewer OB's are fully passivated.

  • Junctions available in 45° and 90°

  • uPVC coupling attached to offtake to allow for ease of connection to PVC property drain.

  • All bolts are supplied with plastic thread protectors.



The Derwent Industries Sewer OB's are ideal for new service connections on existing or new sewer mains. The Sewer OB's can also be used for repair and reconnecting a damaged branch. Sizes are available for new and older styles of sewer mains.


Please refer to installation instructions provided for all installations.


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