Rointe Dalis 200DHW4, Instruction Manual

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- External surfaces such as car parks, hard standings, grassed areas etc. are acceptable
providing that where children play or humans/animals otherwise come into contact with
discharges, a wire cage or similar guard is positioned to prevent contact whilst maintaining
visibility.
- Discharge at high level, e.g. into a metal hopper and metal down pipe with the end of the
discharge pipe clearly visible (tundish visible or not) or onto a roof capable of withstanding
high temperature discharges of water and 3 m from any plastic guttering system that would
collect such discharges (tundish visible).
- Where a single pipe serves a number of discharges such as in blocks of flats, the number
served should be limited to not more than six systems so that any installation discharging
can be traced reasonably easily. The single common discharge pipe should be at least one
pipe size larger than the largest individual discharge pipe to be connected. If unvented hot
water storage systems are installed where discharges from safety devices may not be appar-
ent (i.e. in dwellings occupied by blind, or disabled people), consideration should be given to
the installation of an electrically operated device to warn when discharge takes place.
IMPORTANT
Rointe do not take responsibility for any damage caused from discharges.
Figure 12 - sizing table for copper discharge (D2) pipe for common temperature relief valve outlets
Valve outlet size
(diameter, inches)
Min. size of discharge pipe
before tundish (mm)
Min. size of discharge pipe
D2 after tundish (mm)
Max. allowed length of pipe
after tundish (m)
G 1/2 15
22 9
28 18
35 27
G 3/4 22
28 9
35 18
42 27
8.11.1. Calculated example
The example below is for a 1/2” diameter temperature relief valve with a discharge pipe (D2) having
4 x 22mm elbows and a length of 7m from the tundish to the point of discharge.
The maximum resistance allowed for a straight length of 22mm copper discharge pipe (D2) from a
1/2” diameter temperature relief valve is 9.0m. Subtract the resistance for 4 x no 22mm elbows at
0.8m each = 3.2m.
The maximum permitted length equates to: 5.8m, which is less than the actual length of 7m, there-
fore, calculate the next largest size.
Maximum resistance allowed for a straight length of 28mm pipe (D2) from a 1/2” diameter tempera-
ture relief valve equates to: 18m. Subtract the resistance for 4 x 28mm elbows at 1.0 each = 4m.
Therefore the maximum permitted length equates to: 14m. As the actual length is 7m, a 28mm
diameter copper pipe will be satisfactory.