Process and prefabricated parts for producing branch pieces for pipes

One or a plurality of valve-operated branch pieces can be attached to any point of any pipe. To this end, two opposite openings (16, 18) are made in the pipe (10), and a branch valve body is clamped about the pipe in bracket-like manner at the prepared site.

BACKGROUND OF THE INVENTION 
The present invention relates to a process for producing one or a plurality 
of valve-operated branch pieces for a pipe conducting a medium. The 
invention further proposes embodiments of the parts required for this 
purpose. In many technological fields one is confronted with the task of 
forming branch pieces for a main pipe conducting a medium, said branch 
pieces each diverting a certain amount of said medium from the main pipe, 
with a valve provided at the branching site controlling the amount to be 
diverted. 
Examples of such may be the so-called heating circuit distributors in 
central heating systems, although the medium to be distributed thereby may 
also be oil or lubricant, one may consider pipe branches which become 
necessary in chemical process engineering. The range of applications is 
unlimited. The medium to be circulated may also be gaseous. 
Just like the media to be diverted from a main pipe may be of very 
different nature, the present invention also comprises all kinds of 
materials from which the pipes and the branch pieces are made. These may 
be metallic pipes, iron pipes or pipes made of non-ferrous metals or they 
may also be reinforced or non-reinforced plastic pipes. Even the use of 
glass pipes may be considered. 
Moreover, it is irrelevant for the purposes of the present invention 
whether the branch pieces are installed at a later stage in an already 
existing system, whether they are produced upon completion of a system in 
an assembling state or whether they are prefabricated branch pieces. 
Various means are known for tap-boring pipes which will remain in operation 
during this process. German patent DE 42 39 573 A1 for example discloses a 
tap-boring device for pipes under pressure. This device will first serve 
as a hole gauge for a drilling tool which gauge may be clamped onto said 
pipe. This drilling tool is connected with a valve disk which will assume 
the function of the valve. 
German utility model DE-GM 74 10 858 discloses a tap-boring pipe clip for 
pressurized air and water. Also in this case the drilling tool is provided 
with a sealing element. This prior art aims at providing a pipe in 
operation with a branch piece, with the drilling aid remaining on the pipe 
as a valve organ. 
In contrast thereto, it is the object of the present invention to provide 
any number of valve-operated branch pieces at any point on a pipe which is 
not in operation. 
SUMMARY OF THE INVENTION 
According to the basic concept of the present invention, for each 
valve-operated branch piece two opposite openings are first made in the 
pipe transversely to the main pipe axis. To this end, a hole may be bored, 
by means of a drill, into the two opposite surface areas of the pipe 
transversely to the main axis of the metal pipe. According to the 
invention, a prepared two-part unit composed of a top part and a bottom 
part is placed on the branching site thus defined. The bottom part of said 
prepared unit has a through passage for the medium to be diverted which 
passage matches the bottom predrilled bottom opening. The top part of said 
unit on the other hand includes a valve core which fits into the opposite 
opening. Both parts are firmly and sealingly clamped onto the pipe from 
the exterior. Advantageously, the two halves of the prepared unit may be 
connected via a hinge for this purpose so that the prepared unit may be 
placed onto the two prepared openings like open tongs and is then clamped 
onto the pipe by screwing up or otherwise tightly connecting the free ends 
of said "tongs". 
In accordance with the invention, said clamping onto the pipe may also be 
effected on either side by means of a screwed joint instead of the hinge. 
Further details, features, advantages and applications of the present 
invention may be gathered from the following description of two embodiment 
of the invention.

FIG. 1 shows how a medium-conducting pipe 10 is prepared according to the 
inventive process in a simple manner so that valve-operated branch pieces 
or valve-operated recirculation pieces for recirculating the medium into 
the pipe may be mounted thereon. The pipe may be made of any material such 
as iron, non-ferrous materials, metal, metallic alloys, plastics or glass. 
For use according to the present invention, the pipe may be in an assembly 
state, a state prior to assembly or in a temporarily halted operative 
state. The medium to be diverted or recirculated may be liquid or gaseous. 
It may be oil, coolant, separating agent, lubricant, non-aggressive 
chemicals, or hot or cold water. One field of application is a heating 
circuit distributor in a central heating system. Any other application in 
the construction of systems, in the construction of test systems or for 
subsequent installation in existing systems of this kind is conceivable. 
In contrast to the common prior art, the pipe 10 need not be interrupted or 
provided with a thread or flange or the like at the branching site. As is 
shown in FIG. 1 by way of example, a drill 12 is placed on the site 14 
intended for the branch transversely to the axis of the pipe 10, and at 
right angles to the pipe axis two openings, a top opening 16 and a bottom 
opening 18, are drilled in a single step, thus preparing the pipe 10 for a 
valve-operated branch piece at the drilling site 14. 
The valve with the branch connection piece is preferably a finished 
preassembled unit 20 which is ready for installation after the two 
openings have been provided, and may be placed across the openings 16 and 
18 and around the pipe 10 in a simple, bracket-like manner and clamped 
tightly thereon. 
As shown in FIGS. 3 and 4, the unit 20 is essentially composed of a bottom 
part 22 and a top part 24. Both parts 22 and 24 are connected via a hinge 
26 and may be made of plastics, metal or metal alloys. 
The bottom part 22 comprises a firmly held pipe portion 28 with a through 
passage such as an inner duct 30 which represents the branch. The 
branching is effected via a pipe which is screwed onto a thread 32 by 
means of a union nut. The top opening edge of said duct 30 is surrounded 
by a sealing ring 34 which is stepped for optimum fit. 
The top plastic part 24 holds the fully preassembled parts of the closing 
element for closing the top opening of the duct 30. This closing element 
includes a valve body 40 firmly connected with the plastic top part 24. 
The bottom part of the valve body 40 and the adjoining section of the 
plastic top part 24 are surrounded by a sealing ring 42 which is stepped 
for optimum fit. The valve body 40 guidingly surrounds a valve stem 44 
which is sealed from the top by means of a bush 46. Furthermore, a spring 
48 is provided in the valve body 40 which spring cushions the stem 44. At 
the bottom of the stem 44 a valve disk 50 is provided. At the top of the 
stem 44, the stem is connected with a rotary handle 52 the internal thread 
54 of which engages an external thread 56 provided on the top collar of 
the plastic top part 24. By turning the rotary handle 52, the valve disk 
50 is raised or lowered. 
Of course, this common valve structure may be modified as desired according 
to the purpose of the individual application. What is essential to the 
present invention is merely that the structure composed of a bottom part 
22 and a top part 24 connected via a hinge or in a tong-like manner is 
used such that the bottom part with the sealing ring 34 may first be 
inserted in the opening 18. Then the top part 24 is swung aroung the hinge 
26, with the bottom valve stem 44 and the valve disk 50 being inserted in 
the pipe 10 via the opening 16. Finally, on the side opposite the hinge 
26, the top and bottom parts 24 and 22 are firmly closed as a unit 20 and 
firmly clamped onto the pipe 10 by tightening a screw 60 which has been 
inserted in a thread 62. In this final state, the valve stem 44 and the 
valve disk 50 are axially flush with the through duct 30, and a 
valve-operated branch from the pipe 10 into the duct 30 has been created 
in a simple manner. By turning the handle 52 the branching valve may be 
opened more or less, or closed completely. 
The important advantage here is that a valve-operated branch piece may be 
produced at any site on a pipe by using one single pre-assembled part. 
However, also a two-part unit as shown in FIG. 5 may be used. In this 
Figure, like reference numerals indicate like parts. The difference with 
regard to FIGS. 3 and 4 is that the bottom part 22 and the top part 24 are 
connected by means of a second screw 64 instead of the hinge 26. 
A further advantage is obtained in that the bracket formed by the parts 22 
and 24 insulatingly surrounds the pipe 10 at the branching site. If 
insulation 70 (FIG. 2) is also required for adjacent parts of the pipe 10, 
then the adjacent insulations may also be firmly tightened on the pipe 10 
by clamping the parts 22 and 24. 
FIG. 6 shows an embodiment which is particularly advantageous for branches 
on forward runs. In this Figure, like reference numerals indicate like 
parts. The difference with regard to FIGS. 3 and 4 is that the stem 44 on 
which the valve disk 50 is mounted is firmly fitted into the bush 46, with 
the combination of bush 46, stem 44 and valve disk 50 being movable along 
the axis of said passage or the duct 30 by means of a screw 72. 
Advantageously, the screw 72 may be connected with an external handle (not 
shown). Also in this embodiment, the bottom part 22 and the top part 24 
may be connected by means of a second screw instead of the hinge 26. The 
advantage of the embodiment example shown in FIG. 6 is amongst others that 
when pressure acts on the side of the pipe facing away from the duct 30, 
e.g. due to the fact that the pressure prevailing in the pipe 10 
containing the medium is higher than the pressure in the pipeline screwed 
onto the thread 32, no undesired closing of the valve may occur.