Benchmark Centerstore 120 Installation And Servicing Instructions page 7

Worked example of discharge pipe sizing
Fig. 5: shows a G1/2 temperature relief valve with a
discharge pipe (D2) having 4 No. elbows and length of
7m from the tundish to the point of discharge.
From Table 3:
Maximum resistance allowed for a straight length of
22mm copper discharge pipe (D2) from a G1/2
temperature relief valve is 9.0m.
Subtract the resistance for 4 No. 22mm elbows at 0.8m
each = 3.2m
Therefore the permitted length equates to: 5.8m
5.8m is less than the actual length of 7m therefore
calculate the next largest size.
Maximum resistance allowed for a straight length of
28mm pipe (D2) from a G1/2 temperature relief valves
equates to 18m.
Subtract the resistance of 4 No. 28mm elbows at 1.0m
each = 4.0m
Therefore the maximum permitted length equates to:
14m
As the actual length is 7m, a 28mm (D2) copper pipe
will be satisfactory.
WARNINGS:
•
Under no circumstances should the factory
fi tted temperature/pressure relief valve be
removed other than by a competent
person. To do so will invalidate any
guarantee or claim.
• The cold water combination valve assembly
must be fi tted on the mains water supply to
the CENTERSTORE cylinder.
• No control or safety valves should be tampered
with or used for any other purpose.
• The discharge pipe should not be blocked or
used for any other purpose.
• The tundish should not be located adjacent
to any electrical components.
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