This appraisal is for Derwent resilient seated PN 16 hydrant and air valve isolators and NZ underground screw-down fire hydrants manufactured in compliance with the material and performance requirements of NZS 4522:2010 Underground fire hydrants. This Issue 2 is to close out a future work item that required a AS/NZS 4020 test to be completed for the isolator.

The two product configurations included in the scope of this Appraisal are:

  • Hydrant and air valve isolators with a studded outlet suitable for attaching AS/NZS 4087 Fig B5 DN 100 flanged fittings including spring hydrants, air valves or threaded outlets. The flanged inlet is slotted to accommodate attachment to either AS/NZS 4087 Figure B5 DN 80 or DN 100 flanges.
  • NZ underground fire hydrants in squat and tall versions. The outlet is a 2 TPI threaded outlet and the flanged inlet incorporates slotted holes to accommodate both AS/NZS 4087 Figure B5 DN 80 (146 PCD) and AS 2129 Table D DN 90 (165 PCD), as specified in NZS 4522.

The NZ underground fire hydrants are intended exclusively for the New Zealand market.



Product categoryHydrant Isolators
PA NumberPA 2060 Issue 2
Report holderDerwent Industries Pty Ltd
StandardNZS 4522:2010 Underground fire hydrants
Publication date
Expiry date

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PA 2060 Issue 2 - Derwent - Hyd and AV Isolators and NZ Fire Hydrant-Final-1.pdf PDF