AquaFlo Installation, Maintenance and User Instructions
Page 18 of 24
V 2.01 - October / 2012
Discharge arrangement
General guidance is provide by the diagram on page 19, extracted from the G3 Building
Regulation Guidance. This guidance is available as a free of charge download of the G3
Approved Document from www.planningportal.gov.uk.
The discharge from both the Temperature relief and expansion relief valves can be joined
together via a 15mm end feed Tee.
It is important that any discharge water does not collect in this pipe-work and can run freely to
the tundish. The tundish should be mounted in a vertical and visible position located in the same
space as the unvented hot water storage system and be fitted as close as possible and within
600mm of the safety device e.g. the temperature relief valve. The discharge pipe-work from the
tundish must be routed in accordance with Part G3 of the Building Regulations.
The discharge pipes and tundish should be installed in a visible location away from any electrical
devices, should terminate in a safe place where there is no risk to persons in the vicinity of the
discharge, be of metal and:
•
Be at least one pipe size larger than the nominal outlet size of the safety device unless its
total equivalent hydraulic resistance exceeds that of a straight pipe 9m long i.e. discharge
pipes between 9m and 18m equivalent resistance length should be at least two sizes
larger than the nominal outlet size of the safety device, between 18 and 27m
at least 3 sizes larger, and so on. Bends must be taken into account in calculating the
flow resistance.
An alternative approach for sizing discharge pipes would be to follow BS6700
Specification for design installation, testing and maintenance of services supplying water
for domestic use within buildings and their curtilages.
•
Have a vertical section of pipe at least 300mm long, below the tundish before any elbows
or bends in the pipework.
•
Be installed with a continuous fall.
• It is preferable for the discharge to be visible at both the tundish and the final point of
discharge but where this is not possible or practically difficult there should be clear
visibility at one or other of these locations.
Examples of acceptable discharge arrangements are:
• Ideally below the fixed grating and above the water seal in a trapped gulley.
•
Downward discharges at a low level; i.e. up to 100mm above external surfaces such as
car parks, hard standings, grassed areas etc. are acceptable providing that a wire cage or
similar guard is positioned to prevent contact whilst maintaining visibility.
•
Discharges at a high level; e.g. in to metal hopper and metal down pipe with the end of
the discharge pipe clearly visible or onto a roof capable of withstanding high temperature
discharges of water and 3m from any plastic guttering systems that would collect such
discharges.
Содержание AquaFlo II AF3090
Страница 2: ...Inside Back cover Inside Front cover...
