Classifications

• • G—PHYSICS
  • G01—MEASURING; TESTING
  • G01M—TESTING STATIC OR DYNAMIC BALANCE OF MACHINES OR STRUCTURES; TESTING OF STRUCTURES OR APPARATUS, NOT OTHERWISE PROVIDED FOR
  • G01M3/00—Investigating fluid-tightness of structures
  • G01M3/02—Investigating fluid-tightness of structures by using fluid or vacuum
  • G01M3/04—Investigating fluid-tightness of structures by using fluid or vacuum by detecting the presence of fluid at the leakage point
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
  • F16L—PIPES; JOINTS OR FITTINGS FOR PIPES; SUPPORTS FOR PIPES, CABLES OR PROTECTIVE TUBING; MEANS FOR THERMAL INSULATION IN GENERAL
  • F16L55/00—Devices or appurtenances for use in, or in connection with, pipes or pipe systems
  • F16L55/18—Appliances for use in repairing pipes
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F17—STORING OR DISTRIBUTING GASES OR LIQUIDS
  • F17D—PIPE-LINE SYSTEMS; PIPE-LINES
  • F17D5/00—Protection or supervision of installations
  • F17D5/02—Preventing, monitoring, or locating loss

Definitions

• the present invention relates, in general, to the field of tightness testing devices for an enclosure.
• Leak tests are generally carried out using leak detectors operating either by direct pumping or by sniffing.
• the test esc is easy to carry out when it is a question of verifying the tightness of a closed enclosure or when it relates to small parts.
• the object of the invention is to propose a leak-tightness testing device which, using the same basic design, which is much more mechanically resistant, provides sealing conditions of increased quality and leads to a significantly improved sensitivity, while being able to meet the requirements of intensive industrial use.
• a sniffing chamber which device, being arranged in accordance with the invention, is characterized in that it comprises: a rigid supporting frame made up of several mutually articulated sections to allow the opening of the collar when it is put in place on the enclosure or its removal, said frame being shaped like a gutter having in cross section the general shape of a U open radially inward, and a mantle of relatively flexible material supported by said frame and shaped, at the level edges of the gutter formed by the frame, in deformable sealing lips suitable for sealingly applied to the surface of the enclosure.
• the rigid supporting frame is metallic, in particular made of aluminum alloy.
• the rigid supporting frame is made up of four sections joined one after the other by three articulations mutually offset by approximately 90 °.
• the pumping inside the cha ⁇ iDre contributes to pressing the armature around the enclosure and therefore to maintaining the device in a functional position around the enclosure; it is however preferable to provide locking means to keep the collar in the sealed closure position around the enclosure to be tested, if only to keep the device in place before the pumping means are started.
• the sealing lips have the relative flexibility necessary to apply sealingly to the enclosure while retaining a relative hardness necessary to prevent excessive fatigue, and ultimately prevent rupture of these lips when a very high vacuum is established, the relatively flexible material constituting the mantle must have a Shore hardness of around 40.
• the mantle is made of a plastic material which molds, externally, the rigid frame .
• the sealing lips protrude beyond the respective edges of the rigid gutter and are opened out to define a relatively wide face of support on the surface of the enclosure.
• the device according to the invention as just described makes it possible to detect leaks at the limit of sensitivity of the detector (of the order of 10 ⁇ 9 or ICA 0 [mbar A s "1 ]). remarkable performance is due in particular to the self-sealing property provided by an adhesion of the flexible lips of the sealing mantle on the enclosure (for example on the periphery of the tube) in proportion to the importance of the vacuum created by the pumping, and this whatever the surface defects of the enclosure.
• this device Because of its one-piece and rigid structure, this device is the only part to handle and, moreover, it can be handled by a single operator; it can be set up quickly due to its easy opening and much greater than the size of the chamber, in particular the diameter of a tube, and this opening ability combined with its compactness make it easily installable in areas difficult to access (tangle of tubes, frequently modified installations, ). No joint is reported: there is therefore no risk of pinching of the joint, which again simplifies the conditions for mounting and functional implementation of the device.
• FIG. 1 is a side view, in diametral section, of a test device according to the invention shown in the mounting position; and
• FIG. 2 is an end view, partially broken away, of the device of FIG. 1.
• the leak test device generally designated by the reference numeral 1
• the enclosure 2 is constituted by a tubular section formed by the ends of two adjacent tubes 4a, 4b which are joined (for example by welding, or by any other means) in a sealed manner.
• the two tubes 4a, 4b have different diameters and are of circular outline.
• the test device 1 consists of the meeting of a rigid support frame 5 and a waterproof jacket 6 supported by it.
• the rigid supporting frame 5 is constituted by a metallic structure 10 in the general shape of a gutter annular (in mounting position) having a generally U-shaped cross section open radially inward.
• This annular gutter structure is constituted by a metallic structure 10 in the general shape of a gutter annular (in mounting position) having a generally U-shaped cross section open radially inward.
• a flange 9 is provided on this structure to allow the connection of a pumping machine.
• the metallic structure in annular gutter 10 is formed by the union of several sections 10a, 10b, ... arranged one after the other and mutually articulated in rotation by articulations 11, which allows the opening of the collar during installation on the enclosure 2 or its removal.
• the metal structure in annular gutter 10 consists of four sections 10a to 10d joined by three joints 11 to 11 3 which are arranged with mutual angular offsets of about 90 °.
• Such an arrangement seems to cover a wide range of needs.
• other arrangements are equally possible, with different angular offsets of the joints
• the supporting frame thus formed is rigid (metallic material, in particular aluminum alloy, polymer, composite).
• locking means 12 suitable for bringing together the two free ends of the annular gutter structure 10 and to clamp this structure around the enclosure.
• Said locking means 12 can for example be of the type comprising a hook 13 mounted on one of the sections (10a) and a loop 14 rotatably mounted on a rocking lever 15 fixed on the section (10d) opposite.
• the coat 6 is made of a relatively flexible material supported by the aforementioned frame 5 (for example the frame is overmolded by the material of the coat). This mantle extends continuously over the entire length of the frame and extends laterally on the wings S. At the curvilinear free edges of the wings 3 ( “edges of the gutter), the material is shaped into lips d 'seal 16, deformable and suitable for sealingly applied to the surface of the enclosure.
• the hardness of the material of the coat must be chosen with care, because it is essentially on this that the perfection of the seal and the performance of the device depend. If the material is too flexible, the lips risk being too stressed in deformation under the action of the high vacuum produced in the sniffing cnamore, and in the long term such fatigue risks leading to rupture. Conversely, too high a hardness would prevent the lips from having the flexibility necessary to be applied perfectly on the surface of the enclosure, and conforming to the slightest variations thereof. To reconcile these contradictory requirements as much as possible, it seems that the material of the coat must have a Shore hardness of around 40.
• the coat can be made of any suitable material, in particular a plastic material. Good results have been obtained with polyurethane, silicone and polyprene, but others may be just as suitable. One constraint is that the material must not create, in the presence of vacuum, immediate degassing which would disturb the results of the leak test.
• the jacket 6 covers at 17 the facing ends of the two extreme sections 10a and 10d of the frame 5 so as to seal their connection.
• a device arranged in accordance with the invention proves to be particularly advantageous because of the simplicity of its arrangement and of its handling.
• the mantle is integral with the frame, it can however be detached (demolded) from the latter when necessary (damaged material, absorption of tracer gas leading to a disturbance in the measurements, etc.).
• the frame can then be kept and molded again, which significantly reduces the operating cost of the device. Tests carried out with this device have shown that it is suitable for measuring leakage rates in the range of 10 ⁇ 9 [mbar. L. s "1 ], with quick and simple implementation.
• Such a device was more particularly designed for checking the tightness of the junction lines between magnets in the CERN LHC collider. But its scope is much broader, and it can find use in a wide variety of fields. In fact, this device must make it possible to test the tightness of any installation used for the transport of dangerous or very clean fluids (liquids or gases) before putting into service. Laboratory facilities and medical, chemical, pharmaceutical, agro-food, electronic, cryogenic as well as petrochemical and space production systems require tubing installations which must guarantee a good level of tightness. A leak test carried out by a conventional method requires a long preparation time.
• the time saved by implementing the device of the invention is of the order of 1 to 3 hours depending on the applications, and this only in the absence of leaks.
• a leak exists, it is often very difficult to locate it when a set of tubes is checked; insulating bag systems are produced for each link, then the tracer gas is sent inside them in order to determine where the leak is coming from.
• the reliability of such a process is limited by the tightness of the pouches themselves (in general 10 "" [mbar. T. S "1 ]) which can let out the gas and pollute the other connections. take care of the insulation of each junction and the intervention time becomes very important (from a few hours to a few days).
• the device of the invention eliminates these manipulations since it allows each link to be reliably isolated and guarantees an immediate location of the possible leak.
• the device of the invention allows temporary repair in this case: it suffices to place the device around the leak and to pump in the shell dynamically or by closing the inlet valve (static vacuum) to temporarily maintain the vacuum at an acceptable level while waiting for a programmed shutdown of the accelerator for final repair.

Landscapes

• Engineering & Computer Science (AREA)
• General Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• Physics & Mathematics (AREA)
• General Physics & Mathematics (AREA)
• Examining Or Testing Airtightness (AREA)
• Investigating Strength Of Materials By Application Of Mechanical Stress (AREA)

Applications Claiming Priority (3)

Publications (1)

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ID=9553287

Family Applications (1)

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Citations (2)

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• 1999
  • 1999-12-15 FR FR9915814A patent/FR2802638B1/fr not_active Expired - Lifetime
• 2000
  • 2000-12-12 CA CA002394961A patent/CA2394961A1/fr not_active Abandoned
  • 2000-12-12 BR BR0016416-0A patent/BR0016416A/pt not_active IP Right Cessation
  • 2000-12-12 AU AU28549/01A patent/AU2854901A/en not_active Abandoned
  • 2000-12-12 EP EP00993439A patent/EP1238252A2/fr not_active Withdrawn
  • 2000-12-12 US US10/149,305 patent/US6799452B2/en not_active Expired - Lifetime
  • 2000-12-12 WO PCT/FR2000/003481 patent/WO2001044773A2/fr active Application Filing

Patent Citations (2)

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