Water Supply Industry Interpretations and Advice

  • Area of Interest : Backflow prevention
  • Topic : Maintaining an air gap
  • Title : Pre-rinse spray units for catering use
  • Clause Reference : Schedule 2 paragraph 15 & G15.3
  • Reference Number : B19
  • Decision Date : June 2002

A hose and trigger-operated spray attachment of a catering pre-rinse unit (e.g. plate pre-wash rinse sinks) does not require additional backflow protection provided that it is installed to comply with the requirement for an AUK3 air gap and the unit is not damaged or altered such that the outlet compromises the air gap, for example by remaining below the spillover level of the sink. The AUK3 air gap thus provided gives backflow protection against fluid category 5 risk which the sink represents.

If on inspection of premises the air gap was found to have been compromised, alternative means of providing the backflow protection will be required by the water supplier’s enforcement staff.