Wolf TSW-120 Installation Instructions Manual page 10

Typical discharge
pipe arrangement
safety device
(eg.
temperature
relief valve)
500 mm maximum
300 mm
minimum
metal discharge pipe (D2) from
tundish, with continous fall,
see table an worked example
Sizing of copper discharge pipe 'D2' for common temperature relief valve outlet sizes
Valve Minimum
outlet size of
size discharge
pipe D1*
G½ 22 mm
* See Worked examples and scheme above
Worked example
The example below is for a G½ temperature
relief valve with a discharge pipe (D2) having 4
No. elbows and length of 7 m from the tundish
to the point of discharge.
From Table
Maximum resistance allowed for a straight length
of 22 mm copper discharge pipe (D2) from a G½
temperature relief valve equates to: 9 m
Subtract the resistance for 4 No. 22 mm elbows
at 0.8 m each = 3.2 m
Therefore the maximum permitted length equates
to: 5.8 m.
10
Installation of the tundish
metal discharge pipe (D1) from
temperature relief valve to tundish
tundish
Minimum
size of
discharge
pipe D2*
from tundish
28 mm
35 mm
42 mm
discharge below fixed
grating or as para 1 (b)
Maximum resistance
allowed, expressed
as a length of
straight pipe (ie.
no elbows or bends)
up to 9 m
up to 18 m
up to 27 m
5.8 m is less than the actual length of 7 m
therefore calculate the next largest size.
Maximum resistance allowed for a straight
length of 28 mm pipe (D2) from a G½
temperature relief valve equates to: 18m
Subtract the resistance for 4 No. 28 mm
elbows at 1 m each = 4 m
Therefore the maximum permitted length
equates to: 14 m
As the actual length is 7 m, a 28 mm (D2)
copper pipe will be satisfactory.
Installation instructions DHW cylinders TSW-120/CSW-120
fixed louvred grating
trapped gully
Resistance
created by
each elbow
or bend
1.0 m
1.4 m
1.7 m
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