Table of Contents
Advertisement
cage or similar guard is positioned to prevent contact, whilst maintaining visibility;
and
(d) discharges at high level: e.g. into a metal hopper and metal downpipe with the
end of the discharge pipe clearly visible or onto a roof capable of withstanding high
temperature discharges of water and 3m from any plastic guttering system that would
collect such discharges.
3.63 The discharge would consist of high temperature water and steam. Asphalt, roofing
felt and non-metallic rainwater goods may be damaged by such discharges.
600mm maximum
300mm minimum
Metal discharge pipe (D2) tundish with
continuous fall. See 3.56, Table G3 and
worked example
Table G3 – Sizing of copper discharge pipe 'D2' for common temperature relief valve outlet sizes
V a l v e
Minimum size of
o u t l e t
discharge pipe D1
size
G½
15mm
G¾
22mm
G1
28mm
20
Installation
temperature relief valve to tundish
Tundish
Figure G3: Typical discharge pipe arrangement
Minimum size of
discharge pipe D2
from tundish
22mm
28mm
35mm
28mm
35mm
42mm
35mm
42mm
54mm
HR s & Jumbo : A1007851 - 661Y1200 • E
Maximum resistance
allowed,
expressed
as a length of straight
pipe (i.e. no elbows or
bends)
Up to 9m
Up to 8m
Up to 27m
Up to 9m
Up to 8m
Up to 27m
Up to 9m
Up to 8m
Up to 27m
UK
Discharge below fixed
grating (3.61 gives
alternative points of
discharge)
Fixed grating
Trapped gulley
Resistance
crea-
ted by each elbow
or bend.
0.8m
1.0m
1.4m
1.0m
1.4m
1.7m
1.4m
1.7m
2.3m
EN
Advertisement
Table of Contents
