IL106026A

IL106026A - Branch connector for piping made of a thermoplastic material

Info

Publication number: IL106026A
Application number: IL10602693A
Authority: IL
Original assignee: Polva Pipelife Bv
Priority date: 1992-07-24
Filing date: 1993-06-15
Publication date: 1996-03-31
Also published as: HU9301970D0; PL299655A1; IL106026A0; DE9310595U1; ATE145713T1; CZ148793A3; CZ288614B6; FI933332A0; EP0580222B1; DE69306186T2; HUT67545A; FI103915B1; TW227596B; SK72693A3; FI933332A7; ES2097438T3; EP0580222A1; BR9302925A; PL171278B1; SK281508B6

Abstract

The branch coupling is equipped with a sealing system (9) incorporated into an open housing (10) provided in the internal wall of the end of the tubular element (5) which is equipped with a shut-off means (6) and constituted by: - a flexible circular valve (11) located in the open housing exhibiting a circular central part (14) coupled to its periphery by a connection element (15); - a flexible sealing ring (16) applied to the circular valve (11) and exhibiting a central opening (17), the diameter of which is less of that of the tool used to pierce the pipeline; and - a fixing sleeve (18) which can be inserted into the open housing (10) to hold the circular valve (11) and the sealing ring (16) in place.

Description

·>υοί?ΑΊκηη miria »yn n*mi> qyo ιαηη Branch connector for piping made of a thermoplastic material DRAKA POLVA B.V.

C. 90282 Branch connector for piping made of a thermoplastic material The invention relates to a branch connector for piping made of a thermoplastic material allowing any undesired loss or escape of the fluid conveyed to be avoided when it is placed and set in use on the said piping.

In Belgian Patents BE-A-750,312, BE-A-833 , 318 and BE-A-833,431, the Applicant Company has already provided branch connectors for piping made of a thermoplastic material, comprising an element in the shape of a saddle fitted with means allowing it to be fastened around the piping to be branched and a tubular T-piece connector element, one end of one of whose branches is connected to the saddle-shaped element and whose opposite end is provided with a leaktight and removable closure means, the end of the lateral branch being provided with means allowing its connection to a branch pipe.

When it is set in use, such a connector is placed around some piping and connected to a branch pipe then, after putting on the closure means, the piping is pierced by introducing an appropriate piercing tool into the tubular connector element and, after piercing and extraction of the piercing tool, the closure means is replaced.

During this setting in use, it appears, from then on, that the fluid conveyed by the piping may escape to the atmosphere between the moment of piercing the piping and the moment of replacing the closure means.

It is therefore desirable to fit such a connector with means allowing any escape of fluid to be eliminated, in particular when the fluid conveyed by the piping is noxious or dangerous .

For this purpose, it has already been proposed in United States Patent US-A-3,240,227 to fit a connector of the above-mentioned type with a valve mechanism of the type with a thermoplastic hinge at the base of the branch of the tubular element provided with a closure means.

It has however been observed that the seal system which is the subject of this patent nevertheless exhibits some drawbacks .

Thus, in the embodiment proposed, the valve mechanism is placed in a recess situated in the part with smallest diameter of a conical space of the tubular element. The result is that, at the time of introduction of and working with the cutting tool, the valve mechanism risks being extracted from its housing with a consequent loss in the desired leaktightness .

Furthermore, during the piercing work, the valve mechanism is held open with the consequence of a passage of fluid through the part of the tubular element situated above the valve mechanism.

Finally, the embodiment proposed requires the abovementioned conical space to be relatively large so as to allow the positioning of the valve mechanism, which may present certain design problems in particular when producing connectors intended to be set in use on piping of small diameter.

The Applicant Company has now developed a novel type of branch connector which no longer exhibits these drawbacks and which is, furthermore, illustrated by the figures of the attached drawings, in which: - Fig. 1 is a sectional view of an embodiment of the branch connector according to the invention; - Fig. 2 is a sectional view of the connector according to Fig. 1 showing the operation of cutting the piping to be branched; - Figs. 3 and 4 are sectional views of the elements constituting the seal system.

The present invention relates, hence, to a branch connector for piping made of a thermoplastic material, comprising: a) an element in the shape of a saddle (1) fitted with means (2) allowing it to be fastened around the piping; and b) a tubular T-piece connector element (3), one end (4) of one of whose branches is connected to the saddle- shaped element (1) and whose opposite end (5) is provided with a leaktight and removable closure means (6)/ the end of the lateral branch (7) of the tubular element being provided with means (8) allowing its connection to a branch pipe, in which the branch of the tubular element (5) provided with a removable leaktight closure means (6) is fitted with a seal system (9) preventing any leakage of the fluid conveyed by the piping when the connector is set in use by piercing the said piping, which is characterised in that the seal system (9) is incorporated in an open housing (10) provided in the internal wall of the end of the said branch and consists of: - a flexible circular valve (11) made of an elastomer material whose thickened edge (12) is disposed in the said open housing (10), the said valve having a partial circular cut-out (13) along the majority of its peri- phery, so as to have a circular central part (14) connected to the periphery by a linkage element (15) acting as a hinge; - a flexible packing ring ( 16 ) applied onto the circular valve (11), the said ring also being made of an elas- tomer material, consisting of a circular disc also having a reinforced edge which is disposed in the said open housing (10) and comprising a central circular opening (17) with a diameter less than that of the tool used for piercing the piping; and - a fastening bushing (18) which can be inserted and fixed in the said open housing (10) in order to hold the circular valve (11) and the packing ring (16) in place.

In the connector according to the invention, the seal system constituted by the valve (11) and the packing ring (16) is disposed in an open housing provided in the upper part of the internal wall of the tubular element (5), which facilitates correct positioning and correct and secure holding in place of the seal system via the closure bushing.

The valve (11) and the packing ring (16) are preferably made from an elastomer such as a synthetic rubber which has a hardness of preferably 50 to 70 IRHD and is chosen such as to satisfy the quality standard GIVEG NEN 7212.

It is however possible to make these two elements from different elastomers which have different hard-nesses. In this case, it is preferable to use an elastomer having a hardness of 50 to 60 IRHD in order to make the packing ring and an elastomer of hardness 60 to 70 IRHD in order to make the valve.

As examples of suitable elastomers, mention may be made in particular of synthetic rubbers based on acrylonitrile and butadiene and elastomers based on polyurethanes .

When making the valve (11), it may be advantageous to provide, in the partial circular cut-out (13), for the holding of breakable thin local strips (19) which prevent any movement of the circular central part (14) during storage and transportation of the connector. These local strips (19) are broken only when the piercing tool is introduced at the time of setting the connector in use. In this manner, it is ensured that the valve (11) remains closed until the time of setting in service and that the latter may then operate correctly. This guarantee is particularly advantageous when the branch connector is intended to be fitted to domestic gas ducts in which the gas is distributed under pressures of 30 to 100 mbar.

The fastening bushing (18) has the function not only of ensuring the holding of the circular valve (11) and of the packing ring (16), but also of guaranteeing good leaktightness .

The fastening of the fastening bushing (18) in the open housing (10) after successive fitting of the valve (11) and of the packing ring may be ensured by any means such as adhesive bonding, screwing, etc. According to a preferred embodiment, it is possible to equip the external wall of the fastening bushing (18) with one or more local protuberances (20) which may fit into corres-ponding recesses provided in the internal wall of the open housing (10) so as to ensure locking in place of the fastening bushing (18).

In order to set the connector according to the invention in use, it is sufficient first to fix the connector onto the piping to be branched and to connect the connector pipe, then to withdraw the removable closure (6) and to pierce the piping using an appropriate piercing tool (21), and finally, after piercing and withdrawal of the piercing tool, to replace the removable closure (6) .

When it is introduced into the tubular element (3), the piercing tool passes through the central opening (17) of the packing ring (16) which, taking into account the diameter of its central opening which is less than that of the tool and the flexibility of its constituent material, presses tightly against the piercing tool (21) and thus guarantees perfect leaktightness against any leakage of fluid. The piercing tool (21), after having possibly broken the strips (19), then causes the valve (11) to open, then finally makes the appropriate opening in the wall of the piping.

After opening the piping and during withdrawal of the piercing tool (21) the packing ring (16) first guarantees the desired leaktightness, whilst, at the end of withdrawal of the piercing tool, the circular central part (14) of the valve (11)/ under the action of the pressure of the fluid, presses onto the central opening (17) of the packing ring (16) and thus prevents any subsequent leakage of fluid. After complete extraction of the piercing tool (21), it is then sufficient to replace the removable closure (6).

The seal system as described also allows subsequent temporary closure of the piping, for example by blowing a gas through the tubular element ( 3 ) , or alternatively closure of the branch pipe by introduction of an appropriate closure bushing into the tubular element (3), once again preventing any leakage of the fluid conveyed by the piping.

Claims

C L A I M S

1. Branch connector for piping made of a thermoplastic material, comprising: a) an element in the shape of a saddle («1^ fitted with means ^A* allowing it to be fastened around the piping; and b) a tubular T-piece connector element one end of one of whose branches is connected to the saddle- shaped element and whose opposite end *(t£i is provided with a leaktight and removable closure means , the end of the lateral branch 4^. of the tubular element being provided with means allowing its connection to a branch pipe, in which the branch of the tubular element 4^ provided with a removable leaktight closure means is fitted with a seal system ^ftf* preventing any leakage of the fluid conveyed by the piping when the connector is set in use by piercing the said piping, characterised in that the seal system is incorporated in an open housing ( ΊιιΓ1 ) provided in the internal wall of the end of the said branch and consists of: - a flexible circular valve f "I ) made of an elastomer material whose thickened edge is disposed in the said open housing H^) the said valve having a partial circular cut-out (UL^along the majority of its periphery, so as to have a circular central part connected to the periphery by a linkage element ^ΛΑ) acting as a hinge; - a flexible packing ring f c ) applied onto the circular valve ifrJnifr) , the said ring also being made of an elastomer material, consisting of a circular disc also having a reinforced edge which is disposed in the said open housing (HrO and comprising a central circular opening ^ 7 ) with a diameter less than that of the tool used for piercing the piping; and - a fastening bushing which can be inserted and fixed in the said open housing frlfl in order to hold the circular valve and the packing ring {-M^ in place .

2. Connector according to Claim 1 characterised in that the valve f V and the packing ring ftbfo) are made from an elastomer having a hardness of 50 to 70 IRHD.

3. Connector according to Claim 1 characterised in that the valve ftkt) and the packing ring ( 16.) are made from different elastomers, the elastomer used for making the packing ring ("Iff having a hardness of 50 to 60 IRHD and the elastomer used for making the valve having a hardness of 60 to 70 IRHD.

4. Connector according to Claim 1 characterised in that the valve f*4 is fitted with breakable local thin strips -fflffl ) which prevent any movement of the central circular part (JL^ during storage and transportation of the connector.

5. Connector according to Claim 1, characterised in that the external wall of the fastening bushing (^i.) is fitted with one or more local protuberances which can be fitted into corresponding recesses provided in the internal wall of the open housing +A&f.