Product specifications

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.
ATMOS MULTI Mk 2 version 2008
Page 17