Dual-purpose central heating boilers

The connection strip is for use with a dual-purpose hot water and central heating boiler. The strip comprises four modules made of molded hard plastic and assembled side-by-side by being mutually juxtaposed with tie bars passing through them, the modules being respectively associated with outgoing heating water, outgoing domestic hot water, incoming cold water, and returned heating water, each module including the corresponding stopcocks and ducts together with lengths of a short-circuit duct enabling the modules to co-operate to form a short-circuit on the heating circuit, suitable for feeding water to said heating circuits and for enabling leak tests to be performed when the boiler is not present.

FIELD OF THE INVENTION 
The invention relates to dual-purpose central heating boilers, i.e. to 
devices for heating water in two circuits, one for providing central 
heating by circulating hot water through radiators or the like, and the 
other for providing hot water to be drawn off for the purposes of washing, 
cooking, . . . , and referred to as "domestic" water, with the heat 
necessary for heating the water preferably being generated by burning a 
gaseous fuel. 
The invention relates more particularly to portions for connecting such 
boilers to external pipework for feeding the boiler with cold water or 
with warm water and for taking hot water therefrom. 
BACKGROUND OF THE INVENTION 
In prior embodiments of such devices, it is necessary to interpose a whole 
series of accessories between the boiler as delivered from the factory and 
the external pipework therefor, particularly to make it possible to feed 
circuits with water under pressure (generally coming from an outside water 
main), and to provide respective stopcocks for each of these circuits, 
together safety precautions concerning excess pressure or leaks. 
In addition, with such embodiments, it is not generally possible to apply 
pressure to the central heating circuit comprising the radiators for the 
purpose of leak testing until the boiler is installed: this constitutes a 
drawback while the premises to be fitted is still being built and is 
therefore not protected against theft or damage. 
The invention enables these drawbacks to be remedied, and to this end it 
proposes that the connection portions for boilers of the type in question 
should be constituted by special "strips" which are particularly simple 
and cheap to make, which strips make it possible to test the central 
heating circuit under pressure in the absence of the boiler per se, i.e. 
in the absence of the active portion of the boiler comprising its burner 
and its heat exchangers. 
SUMMARY OF THE INVENTION 
To this end, the invention provides a connection portion of the type in 
question and essentially comprising: 
four molded modules assembled side-by-side by mutual juxtaposition and by 
common tie bars passing therethrough and preferably including threaded 
ends co-operating with clamping nuts; 
wherein the first module comprises an inlet connectable to outgoing heating 
pipework of the boiler, an outlet connectable to outgoing heating pipework 
leading to the radiators, a duct connecting said inlet to said outlet, a 
manual stopcock mounted on said duct, a safety valve connecting said duct 
to a drain, and a length of short-circuit suitable for connecting the 
above duct to the second module; 
wherein the second module comprises an inlet connectable to the outgoing 
domestic hot water pipework of the boiler, an outlet connectable to 
outgoing domestic hot water pipework for at least one tap for drawing off 
water, a duct connecting said inlet to said outlet, a length of 
short-circuit passing through said second module from the first module to 
the third module, and a pressure gauge connected on said length; 
wherein the third module comprises an outlet connectable to the incoming 
domestic cold water pipework of the boiler, an inlet connectable to the 
pipework for feeding cold water under pressure from the outside, a duct 
connecting said inlet to said outlet, a stopcock mounted on said duct, a 
length of short circuit passing through said third module from the second 
module to the fourth module, and a barrier member interposed between said 
last-mentioned length and the last-mentioned duct; and 
wherein the fourth module comprises an outlet connectable to the return 
heating pipework of the boiler, an inlet connectable to the return heating 
pipework coming from the radiators, a duct connecting said inlet to said 
outlet, a stopcock mounted on said duct, and a length of short-circuit 
suitable for connecting said duct to the length of short circuit of the 
third module; 
the various modules being organized in such a manner that the various 
lengths of short circuit included therein are connected end-to-end in 
watertight manner merely by the four modules being juxtaposed. 
In preferred embodiments, use is made of one or more of the following 
dispositions: 
the third module is associated with a safety member which is itself 
connected to the drain of the first module via respective drain lengths 
contained in each of the first three modules and automatically connected 
end-to-end in watertight manner merely by juxtaposing these three modules; 
the barrier member of the third module is a valve having two valve members 
mounted in series between the domestic cold water feed duct and the length 
of short-circuit in said third module, and said valve is associated with a 
"disconnector" safety member and with a central compartment connected to 
the atmosphere and suitable for collecting leaks of water that may occur 
between the two valve members; 
the fourth module includes a delivery valve mounted on the length of 
short-circuit of said fourth module, said valve being urged towards a 
closed position by a spring which is rated in such a manner as to open 
only if pressure loss exceeding a given threshold exists in the heating 
circuit, e.g. because of thermostatic valves closing; 
the stopcock of the fourth module is fitted with a filter that is easily 
removable when the cock is closed, the filter serving to retain impurities 
coming from the heating circuit and preventing them being delivered to the 
heat exchanger of the boiler; 
at least one other molded module is assembled against the assembly of the 
four above-defined modules using the same tie bars that are used for 
assembling said four modules, namely a fifth module comprising an inlet 
connectable to pipework providing an outside feed of gas under pressure, 
an outlet connectable to pipework for feeding the burner of the boiler 
with gas, a duct connecting said inlet to said outlet, and a stopcock 
mounted on said duct, and optionally a sixth module for the various 
electrical connections of the boiler; 
each module is made of hard plastic, which plastic may differ from one 
module to another; 
each molded module comprises a prismatic or cylindrical peripheral band 
whose outline is substantially rectangular with rounded corners, four 
rectilinear channels being disposed in respective ones of the four corners 
of said band for receiving the tie bars, and a plurality of rectilinear or 
bent tubular lengths reinforced by generally plane webs extending 
perpendicularly to the generator lines of the prism of cylinder defining 
the band; and 
the inlets or outlets for connection to the boiler are all disposed on a 
top face of the strip, and most of the inlets or outlets for connection to 
external pipework are disposed on the rear face of the strip. 
In addition to these main dispositions, the invention includes various 
other dispositions which are preferably used together and which are 
described in greater detail below.

DETAILED DESCRIPTION 
In conventional manner, the dual-purpose boiler under consideration 
comprises a housing 1 containing a gas-fired burner 2 fed with gaseous 
fuel under pressure from mains 3 via a gas pipe 4 associated with safety 
means (not shown) and a stopcock 5. 
The closed circuit for heating comprises, inside the housing 1, a heat 
exchanger 6 in which circulating water is heated by flames 7 from the 
burner 2, and outside said housing, pipework 8 passing successively 
through heating radiators 9 and a circulation pump 10. 
Finally, the circuit for drawing off water comprises in succession, 
starting from an external source 11 of water under pressure and generally 
constituted by a water main, external supply pipework 12, a heat exchanger 
13 inside the housing 1 and also capable of picking up heat produced by 
the flames 7, and outlet pipework 14 terminated by at least one faucet or 
tap 15 for drawing off water. 
The invention relates essentially to the connection portion R which is 
interposed between the external pipework 8, 12, and 14, and the internal 
pipework including the heat exchangers 6 and 13. 
In this case, the connection portion R is constituted by a set of modules 
made of molded plastic which are juxtaposed next to one another and which 
are assembled together by tie bars 16 advantageously constituted by rods 
having threaded ends cooperating with clamping nuts 17. 
There are at least four of these modules, and they are allocated 
respectively as follows: 
the first module A to outgoing heating water; 
the second module B to outgoing domestic hot water; 
the third module C to incoming domestic cold water; and 
the fourth module D to returning heating water. 
The first module A comprises an inlet 18 connectable to boiler pipework 19 
for outgoing heating water, an outlet 20 connectable to pipework 21 for 
conveying outgoing heating water to the radiators, a duct 22 connecting 
said inlet to said outlet, a manual stopcock 23 mounted on said duct, a 
safety valve 24 connecting said duct 22 to a drain duct 25, and a length 
of short-circuit 26 suitable for connecting the above duct 22 to the 
second module B. 
The second module B comprises an inlet 27 connectable to boiler pipework 28 
for outgoing domestic hot water, an outlet 29 connectable to the pipework 
14 for conveying domestic hot water to at least one tap 15, a duct 30 
connecting said inlet to said outlet, a length of short-circuit 31 passing 
through said second module B from the first module A to the third module 
C, and a pressure gauge 32 connected to said length 31. 
The third module C comprises an outlet 33 connectable to boiler pipework 34 
for receiving incoming domestic cold water, an inlet 35 connectable to the 
pipework 12 for supplying cold water under pressure from the outside, a 
duct 36 connecting said inlet to said outlet, a stopcock 37 mounted on 
said duct, a length of short-circuit 38 passing through said third module 
C from the second module B to the fourth module D, and a barrier member 39 
interposed between said length 38 and the last-mentioned duct 36. 
The fourth module D comprises an outlet 40 connectable to boiler pipework 
41 for receiving returning heating water, an inlet 42 connectable to 
pipework 43 for returning heating water from the radiators, a duct 44 
connecting said inlet to said outlet, a stopcock 45 connected on said 
duct, and a length of short-circuit 46 suitable for connecting said duct 
44 to the length of short-circuit 38 in the third module. 
These various modules are organized in such a manner that the various 
lengths of short-circuit 26, 31, 38, and 46 contained in the four modules 
are interconnected end-to-end in watertight manner merely by juxtaposing 
the modules. 
To this end, the endpieces of the lengths to be connected together are 
designed to interfit with interposed O-rings 47 received in suitable 
grooves formed in the outside cylindrical faces of the male endpieces in 
the various pairs of endpieces. 
As a result, merely assembling the four modules A, B, C, and D together 
makes it possible automatically: 
to connect a short-circuit channel 26, 31, 38, 46 between the two openings 
18 and 40 which correspond to couplings with the respective ends 19 and 41 
of that portion of the closed circuit for heating which passes inside the 
boiler; and 
to connect the outside pipework 12 for supplying cold water to the heating 
circuit merely by opening the barrier member 39 after the stopcock 37 has 
been opened. 
It should be observed that there is no need for the boiler to be installed 
at this stage, but that it is nevertheless possible to perform leak 
testing under pressure on that portion of the central heating circuit 
which is outside the boiler. 
This can be done merely by placing three plugs (not shown) respectively in 
the three openings 18, 33, and 40 of the connection strip R that are 
represented by crosses in FIG. 1, and then opening the various stopcocks 
23, 37, and 45, and the barrier member 39. 
This facility for performing leak testing under pressure on the entire 
central heating closed circuit apart from the portion thereof lying inside 
the boiler, even when the boiler is not present, constitutes an important 
advantage of the present invention. 
The preferred embodiment illustrated implements various other dispositions, 
and in particular those described below: 
The third module C is associated with a safety member 48 (FIG. 2) organized 
firstly to enable the heating circuit and more precisely the short-circuit 
channel 26, 31, 38, 46 to be supplied with water under pressure from the 
mains, and secondly to make impossible for a portion of the water 
circulating in the heating circuit, and more precisely in the 
above-mentioned short-circuit channel to return to the duct 36, and thus 
to the water mains 11. 
This member 48 is connected to the drain duct 25 in the first module via 
drain lengths 49, 50, and 51 included in respective ones of the first 
three modules A, B, and C and organized, like the above-described 
short-circuit length, so as to be automatically connected together 
end-to-end in watertight manner merely by juxtaposing the three modules 
concerned. 
The barrier member 39 is constituted in this case by a valve having two 
valve members 52 and 53 connected in series on a common rod 54, and 
suitable, respectively, for causing the duct 36 to communicate with a 
compartment a, and for causing the length 38 to communicate with a 
compartment b, with said rod passing through both of said compartments 
which are themselves interconnected by the safety member 48. 
A third compartment c disposed between the two compartments a and b and 
likewise having the rod 54 passing therethrough is connected to the 
atmosphere via a duct 55. 
This duct serves to drain away such drops of water as may leak through the 
seals where the rod 54 passes through the separating partitions, i.e. the 
partition between the compartments a and c, and the partition between the 
compartments b and c, which seals are constituted by o-rings 56, or the 
like. 
It should be observed that the two valve members 52 and 53 are closed 
simultaneously by acting on the single rod 54 only. 
Controlling both valve members together constitutes an advantage compared 
with prior solutions in which the two valve members correspond to two 
separate stopcocks both of which need to be closed after each occasion on 
which the central heating installation is connected to water pressure. 
The safety member 48, sometimes known as a "disconnector", may be 
constituted in any conventional manner and does not form part of the 
present invention. 
The member 48 may be incorporated in the module C, or it may be applied 
thereto, in particular by means of screws. 
The fourth module D advantageously includes a delivery valve 57 (FIG. 2) 
mounted on the length 46, said valve being biased towards its closed 
position by a spring 58 which is rated so as to enable the valve to open 
only if pressure loss in the heating circuit exceeds a given threshold, 
e.g. due to too large a number of thermostatic valves closing. 
The stopcock 45 in the fourth module D is advantageously fitted with a 
filter 59 which is easily removable when the associated cock is closed, 
which filter serves to retain impurities coming from the heating circuit 
and to prevent them from passing into the heat exchanger of the boiler. 
In addition to the four modules A, B, C, and D corresponding to connections 
to be made with water circuits, it may be advantageous to add at least one 
more module on the same ties bars 16 as the above modules. 
This applies, for example, to a fifth module E comprising an inlet 60 
connectable to the pipe 4 for providing an external feed of gas under 
pressure, an outlet 61 connectable to the pipe 4 for feeding the burner 2 
of the boiler with gas, and a duct 62 interconnecting said inlet to said 
outlet, with the above-mentioned stopcock 5 being mounted on said duct 62. 
This also applies to the sixth module F which is used for the various 
electrical connections required by the boiler. 
The molded material from which the modules are made may differ from one 
module to another, and it is adapted to operating temperature, such that 
the modules for conveying a flow of cold water or of cool water (C and D) 
or for providing electrical connections (F) may be made of lower grade 
material than the modules for conveying hot water (A and B) or the module 
for conveying gas (E). 
The material may be a metal such as an aluminum alloy, but it is preferably 
an injected plastic, which has numerous advantages (cheapness, lightness, 
corrosion resistance, . . . ). 
For example, the plastic may be a polyether sulfone (PES), a polyether 
imide (PEI), or a polyphenylene sulfone (PPS) for the modules A, B, C, D, 
and F, and also for a peripheral portion of the module E, with an inside 
portion of said module E that comes directly into contact with the gas 
then being formed by a metal core. 
Alternatively, module E may be entirely made of an epoxy resin. 
Advantageously, each molded module comprises a cylindrical or prismatic 
peripheral band 63 (FIG. 4) whose outline is substantially rectangular 
with rounded corners, four rectilinear channels 64 disposed in respective 
ones of the four corners of the band for the purpose of receiving the tie 
bars 16, and a plurality of bent or rectilinear lengths of tube T 
reinforced by webs V that are generally plane and that extend 
perpendicularly to the generator lines of the prism or cylinder defining 
the band. 
The module which is shown on its own and in perspective in FIG. 4 is module 
B. 
As can be seen in the drawings, all of the connections between the strip of 
valves R and the boiler are disposed on the top face of the strip, whereas 
most of the connections between the strip and external pipework are on the 
rear of the strip. 
Using such a strip makes it extremely simple to install and remove a 
boiler. 
To this end, the strip R is initially mounted on a wall at a relatively 
large distance therefrom, e.g. about 20 cm, by means of two metal cheek 
plates 66 through which the ends of the tie bars 16 pass. 
The connections with external pipework 21, 14, 12, 43, and 4 can then 
easily be established via the waiting inlets and outlets 20, 29, 35, 42, 
and 60 at the rear of the strip R, i.e. between the strip and the wall, 
and this may be done, in particular, by means of screw couplings. 
Thereafter, the boiler can be connected to the strip R after it has been 
installed and connected in this way by placing the boiler above the strip, 
with the endpieces of the lengths of pipework 19, 28, 34, 41, and 4 inside 
the boiler opening out side-by-side and facing downwards at the bottom of 
the boiler, with the boiler then being lowered so as to juxtapose 
appropriate coupling members terminating said endpieces with coupling 
members weighting for them at 18, 27, 33, 40, and 61, and then finally 
interconnecting the juxtaposed pairs of couplings. 
FIG. 4 shows a clip 65 which facilitates such couplings, which clip is 
described in the present Applicant's French patent application No. 89 
08894. 
The above-described lowering of the boiler onto the strip is advantageously 
guided by pegs 67 provided on the top of the strip co-operating with 
complementary recesses in the boiler. 
In any event, whichever embodiment is adopted, the end result is a strip of 
cocks and pipework for a dual-purpose central heating boiler, with the 
structure of the strip being clear from the above. 
The use of such a strip presents numerous advantages, and in particular the 
following: 
the central heating circuit can be tested under pressure without the boiler 
per se being installed; 
the boiler is easily installed and removed; 
the various items of pipework feeding both circuits of the installation 
with water under pressure are implemented and connected simply; 
the modules are assembled to one another simply; and 
long service life, good appearance, and cheapness, with cheapness being due 
in particular to the low cost of the plastic used for making the various 
modules, even when different plastics are used. 
Naturally, and as follows from the above, the invention is not limited to 
the particular application and implementation that has been more 
particularly described. On the contrary, the invention extends to any 
variants thereof.