NBS Source
List your products

Screwed rainwater outlets are recommended where connection to the outlet occurs within the thickness of the slab, and threaded connections will form a completely gas-tight seal. Two-way screw outlets have a female parallel thread to BS 21 for connecting directly to threaded tubes conforming to BS 1387. This ensures a completely watertight seal when screwed fully home into the outlet body.

Screwed rainwater outlets are suitable for direct connection to cast iron pipework to BS 416 or BS EN 877 or to PVC ‘O’-ring socket pipe (for 3HP-F, 4HP-F and 6HP-F outlets only).

General information

LM6 grade aluminium alloy to BS 1490

Uniclass 2015
Gravity rainwater outlets (Pr_65_50_35_37)Primary
Specification data - Gravity rainwater outlets
Product Reference

HP vertical screw outlet



50 mm nominal bore, flat grating.


75 mm nominal bore, flat grating.


100 mm nominal bore, flat grating.


150 mm nominal bore, flat grating.

Contractor's choice

As drawing ___


50 mm PVC adaptor

75 mm PVC adaptor

100 mm PVC adaptor

150 mm PVC adaptor

To suit pipework

Contractor's choice

As drawing ___

Standard product features


LM6 grade aluminium alloy to BS 1490.

Secure gratings:

Gratings are secured with stainless steel fixings that require either a socket wrench or spanner for removal and replacement.

Flow rate (35 mm head over outlet body):

  • 2HP-TD: 1.7 L/s.
  • 3HP-TD: 5.0 L/s.
  • 4HP-TD: 10.7 L/s.
  • 6HP-TD: 13.5 L/s.

Area drained (rainfall intensity 75 mm/hr):

  • 2HP-TD: 81 m².
  • 3HP-TD: 240 m².
  • 4HP-TD: 514 m².
  • 6HP-TD: 648 m².


  • 2HP-TD: 2.29 kg.
  • 3HP-TD: 2.32 kg.
  • 4HP-TD: 4.03 kg.
  • 6HP-TD: 4.13 kg.

Product Options


Gun-metal to BS 1400 available to special order. Gun-metal should be specified for use in conjunction with copper or lead-clad roofs or when connected to copper pipes.


PVC adaptors are available for threaded outlets – HP vertical screw (HP-TD); and HP two-way (HP-2W) systems. PVC adaptors provide a quick and convenient connection to standard PVC pipework. The adaptors are suitable for connection to all types of pipe systems including cast iron socketed or socketless systems.

Similar products from ACO Technologies plc