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.

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
Report holderDerwent Industries Pty Ltd
StandardNZS 4522:2010 Underground fire hydrants
Publication date
Expiry date

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