Worcester HEATSLAVE 9.24 RSF

Fig. 23 Side fiYe application.
Clamping r ing; Slide back. down flu e pipe 25 mm 11 .0 in. ).
Twist as show n. P ass th rou gh a ir duct socket by en t eri n g1 h is
eodf<st. - l
Bor.•case D
Flu e duct.
-
Ai• ducts p ig £ 1
9. OPEN VENT PRIMARY
SYSTEM
See fig . 24 .
NOTE : A 22 mm combi ned feed and ven t pipe must be
connec t ed to the ~ Rc (% i n. B.S.f' .I nt .) connec tion at t he top
of the a pp liance. See Fig. 1.
1. Fo r sizes of fl ow and re turn pi pe work refer to Tec hnical
Data , Secti on 2 and Fig. 2.
2. FEED AND EXPANSION CISTERN
Th e feed and vent p ipe s ho uld be :2 2 mm d iameter rising
conti nuously from the applia nce to the fe ed and ex pansi on
cistern. The u se of long horiz ont al r un s shou ld be av oided.
The feed and expa nsion cistern shou ld be ar ra ng ed so th at
it provides a mini mu m stat ic head of 300 mm { 12 in.) 8bove
the t op of t he applian ce or a bove t he hig h es t poi nt in th e
heating
circ uit , which ever is t he great er.
3. FILLING AND VENTING
A manual air vem is fitte d to tl'le out l et pipe of the bl ack
wate r t o wa t er hea t exc han ge r sit u ated below the boi l er .
air should
be vente d f rom this poi nt manua ll y as fi lling takes
place. See F ~g . 40 .
Any ot her air wit h in the applia nce will be expell ed via t he
feed a nd vent con nectio n or dissi pate d int o t he rest o l the
system. T he heat ing s ys t em should be fi tt ed with manua l
air
ven ts at any hi gh po int .
4. SYSTEM BY-PASS
See T abl e4 .
A
suit able by -passd es ig ne dt o g ive t hemi nim um fl ow rate
ind i cated in T ab le 4 corres ponding to t he heating outpu t
used must be fi tt ed.
A
suitab le pos i tion fo r the by-pass is shown in F ig . 24 . Th e
by -p as s must be connected between the main 22 mm fl ow
and retu rn pip es at lea st 2m (7 ft .) from the a pp liance.
The by·p ass mu st contain a s uit abl e v alve to p fovide
ad ju st ment a nd can be 15 mmdiame t er if the lengt h is l ess
th an 1 m (3 ft .l. lf the l ength of t he by-pass is greater than
1 m
13f t .) then 22 mm diam ete r pi pe must be used. To
ad j us t the by-pass th e applian ce sho uld be operat ed on hot
wa ter a nd cent ral he at i ng wi th t he rad iat or valves a nd
syst em by· pass set fully op en for at le as t 45 m~ nute s . Wit h
the aid of a contac t t h ermometer. balance t he he at in g
sy
st e m. Restrict t he by -pass by the mi nimum am o unt
nec essary to gi ve a t em perat ure rise ac r os s t he fl ow a nd
r et urn pipe of 11 °C 120°F).
5. PUMP
lf t he pum p is fi tte d w it h speed adjust men t it will be s et at
MAX IM UM and s hou ld n ot be redu ced .
6. Th e ap pliance can be used with a sealed water syst em
prov id ed addi ti onal ex ternal comp on e nt s are fitted as
deta iled in Se<: t io n 1 0.
10 . REQUIREMENTS FOR
SEALED
PRIMARY SYSTEMS
1. GENERAL
See Fig. 25.
The installation mus t comp ly w it h t he requireme nt s of BS
6798: 1 987 and BS 5449:1 . For size s o1 flow and ret um
pipew o rk refer to T eclln i ca l Data . Sec t ion 2 and Fig. :7. .
2. SAFETY VALVE
A s pring loaded safety val ve se t to operate at 3 bar (4 5
lb/in
2
)
mu st be used. T he safety va l ve mus t be fitted close
to the app:iance on t he vent pipe by a horizontal or vert ically
upw ard connection. There must not be a ny valves bet ween
the saf ety va lv e and t he app l iance . It sho u ld be accessible
fo r te s ting . The vaive mu st be po s it ion ed . or any disch af ge
p ip e so arranged th at discharge of water or steam from the
va l ve cannot create a hazard to occupants of the premises
or cause damage to electrical components an d wiri ng . The
safety valve should comply with t he gene ral requifeme n ts
/ of BS . 75 9.
22
3. PRESSURE GAUGE
A pressure ga ug e cover i ng 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)(pa nsion vesse l m ust be connected to
th e appliancevent p ipeclo s elothea pp liance. See F ig. 2 5.
Th e ex pansion vessel must be cnosen to suit the volume
of water in the system . Refer to BS . 54 49 :1 1977 , ~lausc
25 . forfurt her details. T he ch~:~ r g e pressure must n ot be less
than the sta tic heact at the po int of co n nection {i.e. height
of the top point of the syst em above the expansion vessel !.
The ra tio of to t al syste m volume to ex pan sio n vessel
vol ume depe n ds ori severa l fac tors suc h as vessel charge
pr es sure. initial system pressure and maximum b oi l et
te mp e rat ure. For mos t s ys tems the r ati o wilt be between
8 : 1 and 12: 1. Se BS. 5 44 9: 1 fo r specific i nformat i on . The
volumeo 1 wa t erin theapplianc eis 2. 71i1res 10 . 59gal l ons ).
SizingTa~e
Air or Nitrogen chl!rg e pres~ur e !b arj o.s 1.0
Pre-press~risa t io '1 pres $ vre (b a r)
None 1 1.0
N cne
1.0
Ellpaosiol'l ve ssel vo l ume llit res l A ~ c .oe ?l Ax O.H
.t- .K0. 11
Ax0 . 2 ~
A ,... SY STE M VOLUM£ !t.ITAESI
5 . MAKEUP
Provision must be made for replacing wa ter l os t from the
system eitl'ler fr om a make up vessel m ou n ted in a positi on
higher t h<~n the t op poin t of the system and con n ecte d
thr
ough a non ret urn va l ve to the system on the r eturn side
on
th e he at ing ci rc u it, or wh ere access to a m ake up ves sel
wo u ld be d iffic u lt , provision for ma ke up can be made by
pn ;-pre s su risati on of the system.
6 . MAINS CONNECTION
T he re must be no co n nec t io n to t he mains w ate r supply
or
to a wa ter sto rage cist ern supplying d omestic w a te r
even
th rough a no n ret urn val ve without the appro va l o~
the local water un dertaki n g.
7. FILLING
The system sho u ld be f itted with a fi ll ing po int at low l eve l.
Me t hods of filli ng and ma ki ng up seal ed s ys t ems are
d
escr i be d in BS 5 376 :part 2 :1 976 Appe nd ix A. Tw o
methods of fi ll in g a sealed sys t em are sho w n in Fig. 2 5.