Atmos Multi 24/80, Installation & Servicing Instructions Manual, Page: 17 / 43

ATMOS MULTI version 2002 Page 17
Worked example
:
The example below is for a G ½ temperature relief
valve with a discharge pipe (D2) having 4 No. 22mm
elbows and length of 7m from the
tundish to the point of discharge.
From Table 1
Maximum resistance allowed for a straight length of
22mm copper discharge pipe (D2) from a G ½
temperature relief valve is: 9.0m
Subtract the resistance for 4 No. 22mm elbows at
0.8m each =3.2m
Therefore the maximum permitted length equates
to 5.8m
which is less than the actual length of 7m.
Therefore calculate the next largest size (28mm ) .
Maximum resistance allowed for a straight length of
28mm-pipe (D2) from a G ½ temperature relief valve
is: 18m
Subtract the resistance for 4 No. 28mm elbows at 1.0
m each = 4m Therefore the maximum permitted
length equates to 14m.As the actual length is 7m a
28mm (D2) copper pipe will be satisfactory.