MEGAFLO 2sf, Инструкция по эксплуатации

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(c) if plastic pipes are used as branch pipes carrying
discharge from a safety device they should be either
polybutylene (PB) to Class S of BS 7291-2:2006 or cross
linked polyethylene (PE-X) to Class S of BS 7291-3:2006;
and
(d) be continuously marked with a warning that no
sanitary appliances should be connected to the pipe.
Note:
1. Plastic pipes should be joined and assembled with
fittings appropriate to the circumstances in which they
are used as set out in BS EN ISO 1043-1.
2. Where pipes cannot be connected to the stack it
may be possible to route a dedicated pipe alongside or in
close proximity to the discharge stack.
Termination of discharge pipe
3.61 The discharge pipe (D2) from the tundish should
terminate in a safe place where there is no risk to persons
in the vicinity of the discharge.
3.62 Examples of acceptable discharge arrangements
are:
(a) to a trapped gully with the end of the pipe below a
fixed grating and above the water seal;
(b) downward discharges at low level; i.e. up to
100mm above external surfaces such as car parks, hard
standings, grassed areas etc. are acceptable providing
that a wire cage or similar guard is positioned to prevent
contact, whilst maintaining visibility; and
(c) 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.
Worked example of discharge pipe sizing
Fig. 12: shows a G1/2 temperature relief valve with a
discharge pipe (D2) having 4 No. elbows and length of
7m from the tundish to the point of discharge.
From Table 4 page 17:
Maximum resistance allowed for a straight length of
22mm copper discharge pipe (D2) from a G1/2
temperature relief valve is 9.0m.
Subtract the resistance for 4 No. 22mm elbows at 0.8m
each = 3.2m
Therefore the permitted length equates to: 5.8m
5.8m is less than the actual length of 7m therefore
calculate the next largest size.
Maximum resistance allowed for a straight length of
28mm pipe (D2) from a G1/2 temperature relief valves
equates to 18m.
Subtract the resistance of 4 No. 28mm elbows at 1.0m
each = 4.0m
Therefore the maximum permitted length equates to:
14m
As the actual length is 7m, a 28mm (D2) copper pipe will
be satisfactory.