2)
Using a set of expansion controls
(Fig. 2 & 3).
If it is not possible to accommodate the expansion in the system pipe work,
it is then necessary to use a set of expansion controls. These comprise of
an expansion vessel and non-return valve (Kit A) and generally a pressure
reducing valve (Kit B). It is however possible to use Kit A without Kit B, but
the mains water pressure must never reach over 3.5 bar for the expansion
vessel to operate correctly. Therefore if the value of mains water pressure
cannot be guaranteed Kit B should be installed.
Dielectric
junctions
Hot
Cold
Pressure relief valve
(6 bar)
Nearest cold water
draw-off
Pressure reducing valve
(set at 3.5 bar)
Isolating valve
(fixed jumper or
1/4 turn ball type)
Cold
water
mains
Expansion vessel
(charge at set 3.5 bar)
Non-return
valve
Supply to other parts
of plumbing system
Discharge
Fig.. 2
EP 10/15
Dielectric
junctions
Hot
Cold
Pressure relief valve
(6 bar)
Discharge to drain
Nearest cold water
draw-off
Pressure reducing valve
(set at 3.5 bar)
Isolating valve
(fixed jumper or
1/4 turn ball type)
Cold
water
mains
Expansion vessel
(charge set at 3.5 bar)
Non-return
valve
Supply to other parts
of plumbing system
Temperature & pressure
relief valve (7 bar/90˚C)
Tundish
Fig. 3
EP 30 R 3KW
5
