Water Supply Industry Interpretations and Advice

  • Area of Interest : Backflow prevention
  • Topic : Type DC arrangements
  • Title : Alignment of the installation requirements for Type DC arrangements
  • Clause Reference : Schedule 2 paragraph 15(5)
  • Reference Number : B39
  • Decision Date : January 2008

In the case of Type DC arrangements the WRAS Technical Committee has agreed that a reduction in the distance between the lowest point of the air aperture and the free discharge point or spillover level of an appliance from 300mm to 150mm, in alignment with the requirements specified in the British Standard and European norm, is acceptable. All other installation requirements remain unaltered.

(Also see interpretation E08)