Worcester HEATSLAVE 9.24 RSF Installation And Maintenance Instructions Manual page 22

Fig. 23 Side fiYe application.
Clamping
ring;
Slide
back.
down
flue pipe 25 mm 11.0 in.).
Twist as shown. P ass through air
duct
socket by entering1his
eodf<st. -
l
Bor . • c a s e D
Flue
duct.
-
Ai• ducts pig£
1
9. OPEN VENT PRIMARY
SYSTEM
See
fig .
24.
NOTE : A
22
m m combined f eed and vent pipe must be
connected to t he
~
Rc (% in.
B.S.f'
.Int.) connect ion at t he t op
of the appliance. See Fig. 1.
1.
For sizes of f low and return pipe work refer to Technical
Data , Sect ion
2
and Fig. 2.
2. FEED AND EXPANSION CISTERN
The feed and vent pipe shou ld be
:2
2 mm d iameter rising
continuously from t he appliance to the feed and expansion
cistern. T he use of long horizontal runs should be avoided .
The
feed
and expansion ciste rn should be arranged so t hat
it provides a minimum static head of 300 m m { 12 in .) 8bove
t he t op of t he appliance or above t he highest point in the
heat ing circu it , whichev er is t he great er.
3. FILLING AND VENTING
A manual air vem is fitted to t l'le outlet pipe of the black
water t o wat er heat exchanger situated below the boiler.
air should be vented from this point manually as filling takes
place . See
F~g .
40.
Any other air within t he appliance will be expelled v ia t he
feed and vent connection or d issipated into t he rest o l the
system. The heating syst em should be fitted with manual
air vents at any high point.
4. SYSTEM BY-PASS
See Table4.
A suitable by -pass designedto give t heminimumflow rate
indicated in Table 4 corresponding to t he heating output
used must be fitted .
A suitable position for the by -pass is shown in Fig. 24 . The
by-pass must be connected between the main 22 mm f low
and return pipes at least 2m (7
ft .)
from t he app liance.
The by·pass mu st contain a suitable v al ve to pfovide
adjustment and can be 15 mmdiameter if the length is less
th an 1 m (3 ft .l. lf the length of t he by-pass is greater than
1 m 13ft .) then 22 mm diameter pipe must be used. To
adjust t he by-pass the appliance should be operated on hot
water and central heating wit h t he radiat or valves and
system by· pass set fully open for at least 45
m~nutes .
With
t he aid of a contact t hermometer. balanc e t he heating
system. Restrict the by-pass by t he minim um amount
necessa ry to give a tem perature rise across the flow and
return pipe
of 11 °C 120°F).
5. PUMP
lf
t he pum p is f itted w ith speed adjustment it will be set at
MAXIM UM and should not be reduced.
6 .
The appliance c an
be
u sed with a sealed water system
provided additional ext erna l components are fitted as
detailed in Se<:tion
1 0.
10. REQUIREMENTS FOR
SEALED PRIMARY SYSTEMS
1.
GENERAL
See Fig. 25.
T he installat ion must comply w ith t he requirements of BS
6798: 1987 and BS 5449:1 .
For sizes o1 flow and ret um
pipew ork ref er
to
Tecllnical Data. Sect ion
2
and Fig .
:7. .
2. SAFETY VALVE
A spring loaded safety valve set to operate at
3
bar
(4 5
lb /in
2
)
must be used. The safety valve must be fitted close
to the app:iance
on
t he vent pipe by a horizontal or vertically
upward connection. There must not be any valves bet ween
t he safety valve
and
t he appliance. It should be accessible
for testing . The vaive must be positioned.
or
any dischafge
pipe so arranged that discharge of water or st eam from the
valve cannot create a hazard
to
occupants of t he premises
or cause damage
to
elect rica l components and w iring. The
safety valve should comply with t he general requifements
/ of
BS. 75 9.
22
3. PRESSURE GAUGE
A pressure gauge covering at least the range 0- 4 bar
10-60 p .s .i.) must
be
1itted to the system
4 . THE EXPANSION VESSEL
A diaphragm type e)(pansion vessel must be connected
to
the appliancevent pipecloselotheappliance . See Fig. 2 5.
The expansion vessel must be cnosen to suit the volume
of water in the system . Refer to
BS . 5449:1 1977,
~lausc
25.
forfurther details . The
ch~:~r g e
pressure must not be less
t han the static heact at
the
point of connection {i. e. height
of t he top poi nt of the syst em above the expansion vessel!.
The ratio of tot al system volume to expansion vessel
volume depends ori several factors such as vessel charge
pressure. init ial system pressure and maximum boilet
temperature. For most systems t he ratio wilt be between
8 : 1 and 12: 1. Se BS. 5449: 1 for spec ific information. The
volumeo1 waterin t heapplian ceis 2 .71i1res 10. 59gallons).
SizingTa~e
Air or Nitrogen chl!rge pres~ure !barj
o.s
1.0
Pre-press~risat io'1 pres$vre (bar)
None
1 1 .0
Ncne 1.0
Ellpaosiol'l vessel volume llitresl
A ~ c.oe?l
Ax O .H .t-.K0.11
Ax0. 2~
A ,... SYSTEM VOLUM£ !t.ITAESI
5 .
MAKEUP
Prov isio n must be made for replacing water lost f rom the
system eitl'ler f rom
a
make up vessel mounted
in
a posit ion
higher
th<~n
t he top point of the system
and
con nected
t hrough a non return valve to the system
on
t he return side
on th e heating c ircu it , or where access to a m ake up vessel
wou ld be difficu lt, provision f or make up can be made by
pn;-pressurisat ion of the system.
6 .
MAINS CONNECTION
There must be no connect ion t o t he mains w ater sup ply
or to a wat er storage cistern supplying domestic w ater
ev en through a non ret urn valve without t he approva l
o~
the local water un dertaking.
7. FILLING
The system should be fitted with a fi lling point at low level.
Met hods of f illing an d making up sealed systems are
descr ibed in BS
5 376:part 2:1 976
Appendix A. Two
m et hods of filling a sealed system are show n in Fig. 2 5.