Mixergy M0008, Installation And Servicing Instructions

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Discharge pipework
Discharge pipe D2
• The discharge pipe (D2) from the tundish should have a verti-
cal section of pipe at least 300mm long below the tundish be-
fore any elbows or bends in the pipework. It should be installed
with a continuous fall of at least 1 in 200.
• The discharge pipe (D2) should be made of metal or other
material that has been demonstrated to be capable of safely
withstanding temperatures of the water discharged and is
clearly and permanently marked to identify the product and
performance standard (e.g. as specified in the relevant part of
BS 7291-1:2006.)
• The discharge pipe (D2) should be at least one pipe size larg-
er 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. for discharge pipes between 9m and 18m the
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.
• Where a single common discharge pipe serves more than one
system, it should be at least one pipe size larger than the larg-
est individual discharge pipe (D2) to be connected.
An alternative approach for sizing discharge
pipes would be to follow Annex D, section D.2 of
BS 6700:2006 + A1:2009 Specification for design,
installation, testing and maintenance of services
supplying water for domestic use within buildings
and their curtilages.