Ground connection of a pipe line

0001The invention relates to an electrical ground line a metallic insert a in a flange of a Pipe clamped seal with Isolierstoffmantel wherein for connecting the pipe flanges each having a plurality of holes the pipe flanges solid clamping screws are provided and wherein the metal insert for deriving an electrical Charging a between the pipe flanges of the flange outgoing earth strap has.

0002Piping, chemical plants or the like in often be made of special materials and / or internal to Enamel are, often need during assembly at many Sites are interconnected via flanges. In principle it can be formed, for example, welded, Flanges are bolted together. Alternatively, two to be screwed together loose flanges for connecting the tube ends are used.

0003If the pipe ends or flanges are not directly abutted may be, but seals, especially Sealing rings, are between inflict, the seals must usually be in the assembly centers. For inexact centering the seal, the respective connection leak and / or it can be the passage cross section can be reduced.

0004Another problem, involved in pipelines, where Rechargeable fluids such as gasolines (Hepthan-hexane), toluene, Xylene, ether, dioxane, etc. are to be encouraged. In these Cases insulated cable parts with insufficient grounding are so high electrostatic charge that ignitable discharges are conceivable. This applies for example to the inside enamelled pipelines outside epoxy polyester powder coatings are provided as corrosion protection. Such Coatings are poorly electrically conductive.

0005The electrostatic charging of the respective tubular member itself usually makes the smaller problems; it is sufficient to line to ground any point and at any (flange) joint electrically conductive transitions, for example by flap discs, creating rough sheet metal discs, or the like.

0006Intricately it, the seals mentioned itself to earth. For this purpose, in current practice, the metallic Insert, eg a corrugated ring, each sealing a separate wireline grounded. Given the wireline is to an integrally formed on the metal insert seal earthing lug clamped. So if the pipe fitter each Line has fully installed, must each seal be grounded by an electrician. This often head eg work to be performed requires the bolting together multiple Loops and rings, to provide a secure electrical contact to accomplish.

0007The invention is based on the object, the mechanical centering the seals during assembly of the respective pipeline and the electrical earth of the metallic gasket ease; the respective aid effort should reduced and the work result is to be improved; in particular, the aim is without separately to each sealing ring or its grounding strap to be clamped wire lines get along.

0008The inventive solution is in the characterizing part of claim 1 described. The solution for the above-mentioned Ground line essentially is that the grounding strap to herum- the periphery of each tube flange and a on the remote from the other pipe flange back over extends the seat of the respective clamping screw and that the Earthing strap a centering for passing the clamping screw on the other pipe flange facing Flanschvorderseite and a corresponding hole on the ground Flange has. In the present invention, it is irrelevant, whether it is molded to determine the respective tube Flanges or is one or more parts loose flanges. The grounding strap can also referred to as grounding tongue will.

0009According to the invention the grounding lug at least two holes and it is so long that it - approximately radially (with respect to the pipeline or axis) out of the seal out - around the periphery of a pipe flange to above the bore opening extends to the flange back. In the Mounting the earthing strap so the Flanschperipherie wrapped in that the two holes in the grounding lug with a provided for a clamping screw flange bore alignment. The earthing strap is therefore when inserting the screw in the hole pierced twice by the same screw.

0010The grounding clip of the invention has at least two holes; at least two of these holes - so-called main holes - to approximately the diameter of the associated clamping screws Flange own. In addition, holes (possibly different diameter), eg for the connection of an electrical Line, be provided. The spacing of said two main holes on the length of the grounding strap to so its great that the grounding strap (the for passage Plug respective clamping screw) without harmful voltage - but possible at the Flanschperipherie fitting - around the periphery is laying around.

0011The located at opposite longitudinal ends of the earthing strap Main holes of earthing lug have different Objects and advantages. The main hole at the free longitudinal end of the Earthing strap is on the outside of the back of the respective Flange when tightening between clamping screw and expedient a spring washer or the like electrical contact means clamped. About This first main hole, the electrical Contact the pipeline and thus to the earth. It can therefore be called a grounding hole. The other main hole of the earthing strap, the same approximate Distance from the pipe, flange or sealing middle (or - axis) is like having respective flange bore, is relatively close to the seal or even in the area of ​​the seal. It acts on the passage plug or bead of the two Main holes on a clamping bolt centering with respect to the seal and is therefore called centering. If different flange types with one and the same type of seal should be to equip, can (to adapt) or two more grounding and / or centering on distance in the grounding lug be provided.

0012The two main foraminous grounding strap is useful in one piece from the same material as the metallic Gasket. This may in particular their duty then meet well when the a corrugated ring, with respect to Flange axis coaxial rings is formed. Such Deposit has considerable dimensional stability. One of the Insert molded earthing strap can therefore be effortlessly Do not twist about its longitudinal axis.

0013By one and the same action will be according to the invention at the same time a simplified mechanical centering and a simplified achieved electrical grounding. Screwing the grounding hole reached the pipe fitter electrical Grounding of the seal without an electrician called in would be. Furthermore, violations of grounding or damage to the lying close to the Flanschperipherie Earthing strap for additional pipe installations in the neighborhood less than feared in conventional wire grounding. Finally, can the grounding function of the present invention Earthing strap already inspected visually, special Testers are not required.

0014Reference to the schematic representation of exemplary embodiments are details of the invention described. Show it:<dl tsize="7" compact="compact"><dt><b>Fig. 1</b></dt><dd>a section parallel to the tube axis by a flange; and</dd><dt><b>FIG. 2</b></dt><dd>the plan view of the metallic insert a Sealing ring with integrated grounding strap.</dd></dl>

0015In the embodiment of Fig. 1 it is assumed that a glass-lined pipe 1 of steel pipe flanges at their is to be connected. 2 An enamel layer 3 of the pipe inside to the exemplary embodiment, the abutting surfaces of 4 Flanges cover. 2 Between the abutment surfaces 4 after placed Fig. 1 is a PTFE-coated seal 5 (PTFE = polytetrafluoroethylene). The seal 5 is a substantially as resilient corrugated ring formed (with concentric corrugation) contain metal insert 6, the section in the illustrated is U-shaped, surrounded by a PTFE jacket 7; the closed U side is facing the tube axis. 8 On the metallic insert 6 is according to Fig. 1 and 2, a grounding plate 9, preferably one piece (ie the insert 6 and the tab to 9 of a part, for example sheet metal, made), formed. The grounding strap 9 to FIG. 2, has two (main) holes, namely a centering hole 10, substantially adjacent to the body the liner 6, and a grounding hole 11 in the area of ​​free Longitudinal end 12 of the grounding strap. 9

0016To connect the two pipe flanges 2 of FIG. 1 are in Embodiment (split) loose flanges 13. In between the loose flange 13 and the outer or back of Flanges 2 is a rough sheet 14 down to the electrical ensure contact at this point. The loose flanges 13 have more than one, for example four holes 15 (see FIG. Fig. 2), is to be drawn through each of a clamping screw 16. Between the screw head 17 and backing flange 13 and between Nut 18 and backing flange 13 is for ensuring an electrically conductive compound each have a serrated washer 19 or the like is inserted. Thus, when the pipe 1 at any Point is grounded, all the parts described the line with loose flanges and screws mitgeerdet. A Grounding of the metallic mesh 6 of the gasket 5 is, however, not yet been reached in this way.

0017To ground the metallic mesh 6 serves the separate Earthing lug 9. This has according to the invention a centering 10 and a grounding hole 11 (each about the diameter of flange 15). The position of the center hole 10 in relation to the body of the metallic mesh 6 and the spacing of the holes 10 and 11 are chosen such that a and the same clamping screw 16 during installation twice by the around the periphery 20 of one (in Fig. 1, right) loose flange to lead 13 guided around grounding strap 9 through is. The mutual distance of the two holes 10 and 11 So to be selected so large that the grounding lug 9 in the arrangement of FIG. 1 without undue longitudinal tension to the outside Peripheral 20 is around set. During assembly, the Screw 16 in the plug 21 through the first in Fig. 1 left loose flange 13, then through the center hole 10, then by the other loose flange 13 and finally through the ground hole 11 put through. Through one or more serrated washers 19 between the screw head 17 and nut 18 and backing flange 13 is an electrical contact with minimal resistance and between the ground plate 9 and made the tubular body, so that the desired grounding of the gasket 6 is also achieved.

0018There is an electrical ground line a metallic Insert a clamped in a flange of a pipeline, go across the pipe flanges insulated seal. The metal insert has an out of Flange radially outgoing earth strap. Neighbouring Flanges are using by flange holes solid terminal screws interconnected. To the metallic grounding pad, the grounding lug around the periphery is of each a pipe flange around and on its Back on the seat of the respective clamping screw out extended and each having a hole for the passage of the clamping screw equipped on the back and front of the tube flange.

LIST OF REFERENCE NUMBERS

0019<dl tsize="3" compact="compact"><dt>1</dt><dd>= Pipeline</dd><dt>2</dt><dd>= Pipe flange (1)</dd><dt>3</dt><dd>= Enamel layer</dd><dt>4</dt><dd>= Abutment surfaces (2)</dd><dt>5</dt><dd>= seal</dd><dt>6</dt><dd>= Insert (5)</dd><dt>7</dt><dd>= Jacket (5)</dd><dt>8th</dt><dd>= Tube axis</dd><dt>9</dt><dd>= Earthing strap</dd><dt>10</dt><dd>= centering</dd><dt>11</dt><dd>= Grounding hole</dd><dt>12</dt><dd>= Longitudinal end (9)</dd><dt>13</dt><dd>= Losflansch</dd><dt>14</dt><dd>= Rough sheet</dd><dt>15</dt><dd>= Bore (13)</dd><dt>16</dt><dd>= Clamping screw</dd><dt>17</dt><dd>= Screw head</dd><dt>18</dt><dd>= Nut</dd><dt>19</dt><dd>= Serrated washer</dd><dt>20</dt><dd>= O (13)</dd><dt>21</dt><dd>= Plug-in direction</dd></dl>