DE8414099U1 - GAS SHUT-OFF VALVE - Google Patents

Description

Gas shut-off valve |

The invention relates to a gas shut-off valve with an inner part which is attached to a cavity for the receptacle a shut-off means of the gas shut-off valve and to which a connecting pipe is connected, the Inner part and the connecting pipe electrically from each other via a high temperature resistant, flame retardant Insulating material are insulated.

It is known that in underground pipes made of metal - such as gas pipes - leakage currents due to Creep stresses occur and cause harmful corrosion. Therefore, such lines are on the part the operator is supplied with auxiliary currents to compensate for the disadvantageous leakage currents in order to protect against corrosion to ensure.

At the point where the line leads into a house, however, the "responsibility" of the operator or provider ends of the pipes laid in the ground, and at this point of separation the gas shut-off valves of the input mentioned genus is used and installed.

to prevent creeping voltages or currents get into the house, where they migrate to the power grid

the gas shut-off valve according to Art built up of an electrical insulating piece, i.e. the existing relevant parts - connecting pipe and inner part - are electrically isolated from each other, which is an important feature of a gas shut-off valve.

In addition to the insulation mentioned, there is also a gas shut-off valve yet another important aspect, which is the mechanical stability and load regards. The underground lines mean that considerable forces act on the gas shut-off valve can. Such a case is given when earthworks using an excavator or the like over the Steel pipe forces are directed to the gas shut-off valve. The latter must therefore be able to both axial and to be able to absorb radial forces.

In known gas shut-off valves, it has been shown in practice that the axial and radial force absorption is frequent is not sufficient. The forces that occur go beyond the insulation required for the reasons mentioned above and are "caught" by it. There is a risk of shearing off, causing the gas shut-off valve becomes unusable with the dangerous consequences of uncontrolled escaping gas.

This is where the invention comes into play, which is based on the object of avoiding the above disadvantages, a gas shut-off valve to create that with a flawless electrical Isolation ensures a firm and secure fit of the electrically isolated parts, so that the gas shut-off valve can withstand extreme radial and axial forces.

This object is achieved in the gas shut-off valve mentioned in the preamble of claim 1 in that that the outer wall of the connecting pipe at its end facing the inner part is conical with in the direction of the Inner part is designed with an increasing outer diameter, since a more encompassing the inner part and the end of the cone annular outer jacket is provided, which is conical in the area of the connecting pipe with pointing away from the inner part Direction of decreasing inner diameter is formed that between the cone end of the connecting pipe and a first conical insulating ring is arranged on the outer jacket, and that the inner part as well as the connection pipe in a shrink fit with the outer jacket.

The essential feature of the gas shut-off armature according to the invention can be seen in the fixed shrink fit in connection with the conical design. This will be

achieved two significant advantages. On the one hand, because of the conical design, the insulating ring is also the There is practically no risk of shearing off, and for others the shrunk connection means one fcxtremely tight fit to absorb axial and radial forces.

The invention is based on the consideration that the possible forces occurring go through the insulation, which - rather as a previous weak point in known ones Gas fittings require a special arrangement. This important aspect is in the invention by the conical Seat taken into account, which ensures that shearing off, especially in the case of dangerous tensile forces of the insulating material is avoided.

The stable mechanical structure or the tight fit of the individual parts can, in an expedient configuration, of the Invention can be further improved in that the outer jacket has a conical inner surface has axially extending knurling through which a force flow is established with the conical insulating ring can be.

Another advantageous embodiment of the invention provides that on the outer jacket at its cone end

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a protective cap made of plastic is placed, which rests against the connecting pipe. This can avoid that between the outer jacket and the connecting pipe due to metallic deposits an electrical conductive bridge is created.

Further expedient refinements and developments of the invention are specified in the subclaims and the drawing can be seen as an embodiment of the invention

a partial cross-sectional view of a gas shut-off valve

shows. The in their entirety with the reference number 10 j;

designated gas shut-off valve has, in a manner known per se, a housing 12 with a lower flange 14, which Has bores 16 for attachment by means of a screw connection.

Further, the Gasabsperrarmatur comprises a cavity 18 in which Y is adjacent a metallic inner part 20th At the cavity 18 b ^ w. a connecting pipe 22 made of metal is connected to the inner part 20, and for the purpose of insulation an insulating ring 3 2 is provided between the inner part 20 and the connecting pipe 22.

Two alternatives for sealing are shown in the drawing. In the right half of the picture can you can see a flat seal 34, while O-rings 36 are shown in the left half of the figure. It can a soft iron seal - e.g. copper - can be used.

As an outer part, the gas shut-off valve has a metal outer jacket 26, which the cavity 18, the Inner part 20 and partially also the connecting pipe 22 covers or surrounds.

According to a further feature of the invention is the Outer jacket 26 is conical at its upper end and provided with a conical end 28. Correspondingly, it sits also the lower end of the connecting pipe 22 at this point a cone end 24, and between this and the cone end 28, an insulating ring 3O is arranged.

An O-ring 38 for sealing is embedded in a groove on the outer circumference of the inner part 20, and another O-ring 44 is located at the lower end of the outer jacket 26 at the transition point to the housing 12.

About the creation of an electrical bridge through metal deposits or the like between the outer jacket

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and to prevent the .connection pipe 22 is on the outer jacket 26 a protective cap 40 made of plastic is attached. Finally, there is an operating lever in the drawing 42 for the operation of the gas shut-off valve 10 is shown.

In the arrangement described so far, two features are particularly noteworthy: on the one hand, the conical Training or the cone ends 2 4 and 28 and on the other hand the shrink fit of the outer jacket, which ensures that the gas shut-off valve can absorb sufficient axial and radial forces.

To prepare the shrink fit, the outer shell 26 is about 150 - heated to 350 ° C, and since ζ inner part 10 is set to about - subcooled 19O ° C. The two parts are then brought into one another, the outer jacket 26 cooling down and the inner part 20 heating up.

Thus, the inner part 20 experiences due to the heating Expansion, while the cooling outer jacket 26 experiences an opposite length expansion. To this Way, the parts get in an extremely tight shrink fit.

In the area of the cone end 28, the outer jacket 26 can be attached

its inner surface with an axially extending knurling (not shown) be provided by which an additional frictional connection with the insulating ring 30 is produced.

Due to the conical shape of the cone ends 24 and 28, tension is also achieved in the axial direction, so that the seat as a whole is very firm and stable in all directions. The conical seat enables in the upper area also the transmission of a torque

As an insulating material for the insulating rings 30 and 32 a high-temperature-resistant, flame-retardant, solid, non-flowable plastic is used. Through this is excluded that the insulating material in a Basement fire of the house melts and flows out. Otherwise it could be under pressure Flow out the gas from the fitting and push out the insulating material. The outflowing that ignites Gas could cause considerable damage. These disadvantages are in the invention because of high thermal load capacity of the insulating rings 30 and 32 is not given.

The protective cap 40 already mentioned above forms a cavity 46 around the connecting pipe 22 in order to prevent the formation of a moisture bridge in the case of dew zones. In an expedient embodiment of the invention, the protective cap 40 can be provided with slots at the top / to enable ventilation of the cavity 46.

Claims (9)

dipL.-ingV üwethömen EUROPEAN PATENTATTORNEY Jeschke, Immanuel 400/1 Claims for protection 1. Gasabspiirrarmatur with an inner part which is adjacent to a cavity for receiving a shut-off means of the gas shut-off valve and to which a connecting pipe is connected, the inner part and the connecting pipe electrically isolated from each other via a high-temperature-resistant, flame-retardant insulating material, characterized in that the The outer wall of the connecting pipe (22) is conical (24) at its end facing the inner part (20) with an outer diameter that increases in the direction of the inner part (20) so that an annular outer jacket ( 26) is provided, which in the area of the connecting pipe (22) is conical (28) with decreasing direction in the direction away from the inner part (20) Inner diameter is formed that between the cone end (24) of the connecting pipe (22) and the outer jacket (26) a first conical insulating ring (30) is arranged, and that the inner part (20) and the Connecting pipe (22) are in a shrink fit with the outer jacket (26). 2. Gas shut-off valve according to claim 1, characterized in that the outer jacket (26) has an axially extending knurling on its conical (28) extending inner surface. 3. Gas shut-off valve according to one of the preceding claims 1-2, characterized in that a protective cap (40) made of plastic is placed on the outer jacket (26) at its cone end (28). 4. Gas shut-off valve according to one of the preceding claims 1-3, characterized in that a second insulating ring (32) is arranged between the inner part (20) and the connecting pipe (22). 5. Gas shut-off valve according to claim 4, characterized in that a seal (34; 36) is provided between the second insulating ring (32) and the connecting pipe (22) and between the insulating ring (32) and the inner part (20). 6. Gas shut-off valve according to claim 5, characterized in »that the seal is formed by an O-ring (36). 7. Gas shut-off valve according to claim 5, characterized in that the seal is formed by a flat seal (34). 8. Gas shut-off valve according to one of the preceding claims 1-7, characterized in that a groove is embedded in the outer surface of the inner part (20) in which an O-ring (38) is located. 9. Gas shut-off valve according to claim 3, characterized in that the protective cap (40) is provided with slots.