CN201757696U - Low temperature pipeline welding bead leak detection tool - Google Patents

Abstract

The utility model discloses a low temperature pipeline welding bead leak detection tool comprising a tool body and a conversion joint. The tool body comprises a pipe body and a circular ring pipe body welded on the outside of the pipe body. The pipe is provided with an installation hole, which is welded with a short tube. The tool body can be cut symmetrically along the axial direction of the pipe body. The end of a short pipe is provided with a conversion joint, which is constituted by a lock nut, a compaction gasket, a sealing ring and a quick-release clamp. The conversion joint is connected to the leak detection tool through the quick-release clamp. The inner diameter of the circular ring pipe is smaller than the outer diameter of the pipe body, and the inner diameter of the pipe body as well as the inner diameter of the circular ring pipe is a little larger than the outer diameter of the detected pipe. The utility model has advantages of simple structure, convenient, reliable connection, use, low costs, and improving the sensitivity of the leak detection tool without being influenced by the disturbance of helium leakage from elsewhere.

Description

Cryogenic piping weld seam leak detection tool equipment

Technical field:

The utility model relates generally to a kind of cryogenic piping weld seam leak detection tool equipment, be mainly used in the leak detection of the very high various cryogenic piping weld seams of leak rate requirement, as: various Cryo Refrigerator internal pipelines, various cryogenic vacuum pipelines, various magnet experiment cryogenic systems, superconducting Tokamak etc.

Background technology:

The general exigent vacuum of cryogenic system is conducted heat to reduce gaseous exchange, reduces the thermal load of device.So cryogenic system pipeline and equipment generally all are installed in the container that has vacuum insulation.The pipeline of cryogenic system has many weld seams in installation process, in order to reach very condition of high vacuum degree, the leak rate of butt welded seam requires very high.Just need leak detection, leak test plant commonly used is a helium mass spectrometer leak detector.Main leak hunting method commonly used has the suction gun method and finds time to spray the helium method.The suction gun method is exactly to fill helium with at tested pipe interior to press, and inhales the commissure in the pipeline outside with suction gun.If detected weld has leakage, helium will spill and be detected by suction gun by weld seam, and helium mass spectrometer leak detector will reaction and display goes out the size of leak rate.Find time to spray the leak detection of helium method, will vacuumize in the pipeline exactly, and be connected to helium mass spectrometer leak detector, at the outside commissure spray of pipeline helium, if weld seam has leakage, helium will be inhaled into leak locator by weld seam.Suction gun method ratio of precision finds time to spray low 1 to 2 order of magnitude of helium method, and the omission possibility is big, and the influence that is subjected to other places weld seam leakage helium simultaneously is big, erroneous judgement easily.Ordinary priority adopts and finds time to spray the leak detection of helium method in the leak detection.Find time to spray the helium method, pipe interior need be found time, and require the interior helium of pipeline residual very low, otherwise leak locator just can't be worked.But we often run into cryogenic system and can't carry out pipe interior and find time, and perhaps the pipe interior helium is residual very high, and can't find time to spray the leak detection of helium method.When finding time to spray the leak detection of helium method in addition, the helium pressure reduction on pipeline both sides has only 1bar, know that according to formula (1) size of leak rate is square being directly proportional with the helium pressure reduction on pipeline both sides, in fact the cryogenic piping major part is all worked under high pressure, so find time to spray leak rate that the helium method detects and be far smaller than the leak rate of pipeline under in working order sometimes with common.

$Q=\frac{P^2}{{\mathrm{<figure-callout\; id="2"\; label="P\; atm"\; filenames="HSA00000054262100021.png"\; state="\{\{state\}\}">P</figure-callout>}}_{\mathrm{atm}}^{}}\&CenterDot;\frac{{\mathrm{\&eta;}}_{293K}}{{\mathrm{\&eta;}}_T}\&CenterDot;Q_{\mathrm{atm},293K}---\left(1\right)$

$\frac{{\mathrm{\&eta;}}_{293K}}{{\mathrm{\&eta;}}_T}={\left(\frac{293}{T}\right)}^{\mathrm{\&alpha;}}$

The utility model content:

The purpose of this utility model is that to find time to spray in the helium method helium pressure reduction less in order to remedy the deficiency of prior art, a kind of cryogenic piping weld seam leak detection tool equipment to be provided, having solved, and pipes can't be found time and found time to spray the situation of helium method leak detection in those.

The utility model is achieved through the following technical solutions:

A kind of cryogenic piping weld seam leak detection tool equipment includes frock main body and X-over, it is characterized in that: described frock main body: include body, the body two ends are welded with interior annulus respectively, and described interior internal radius is less than internal diameter of tube body; Be welded with the short tube of a UNICOM on the tube wall, described body cuts vertically, and the frock main body is divided into two parts; Described X-over includes the Quick Release Hoop that an end and leak locator are connected fast, the other end of Quick Release Hoop is provided with external thread, external thread screw togather outward have central openings, front end have in the ring edge swivel nut, be provided with packing ring between the front end face of ring edge and Quick Release Hoop in the described swivel nut, described short tube is plugged in the other end of described Quick Release Hoop, and fastening by swivel nut.

Described a kind of cryogenic piping weld seam leak detection tool equipment, it is characterized in that: described annulus internal diameter of tube body is littler than body external diameter, described internal diameter of tube body and annulus internal diameter of tube body all are a bit larger tham tested outer diameter tube, and internal diameter of tube body is usually slightly larger than the (short tube of tested pipeline of general 5mm～10mm), the internal diameter of annulus body is than the big 0.5mm of tested outer diameter tube, and described body length is about 8cm.The diameter of tested pipeline has a variety of, and described X-over can publicly use.

The utility model has the advantages that:

1, easy to connect reliable

Adopt the general clip interface of general KF, reach the purpose of quick-release.Vacuum mud can be reused, and uses also very simple;

2, process simple cost economic

Only need process one for a kind of pipeline, processing, and low cost easily.To multiple pipeline specifications, can make serial frock;

3, improved the sensitivity of leak locator

Use this frock, can improve the helium pressure reduction of tested pipeline both sides, amplified the helium leak rate, solved the common helium method leak detection both sides pressure reduction problem less than normal of finding time to spray;

4, be not subjected to the interference of other places helium leak

Solved the problem of easy erroneous judgement of suction gun method and omission;

5, having solved a lot of pipelines can not find time, and can find time but helium is residual very high and cause spraying with finding time the situation of helium method leak detection in the pipeline

Description of drawings:

Fig. 1 is the utility model structural representation.

Fig. 2 is the utility model frock main body front view.

Fig. 3 is the utility model frock main body vertical view.

Fig. 4 is the utility model frock main body exploded chart.

Fig. 5 is the utility model X-over sectional view.

Embodiment:

A kind of cryogenic piping weld seam leak detection tool equipment includes frock main body and X-over, and described frock main body includes body 1, and body 1 two ends are welded with the interior annulus 2 of one, and body 1 middle part is welded with the short tube 3 of UNICOM, and described body 1 symmetry vertically cuts; Be divided into two parts.

X-over 4 includes the KF25 Quick Release Hoop 8 that an end and leak locator are connected fast, KF25 Quick Release Hoop 8 other ends are provided with external thread, external thread and have central openings, front end have in the swivel nut 5 at ring edge cooperate, be provided with packing washer 6, O-ring seal 7 between described swivel nut 5 and the Quick Release Hoop 8, described short tube 3 is plugged in the other end of described Quick Release Hoop 8, and fastening by swivel nut 5.

During use, tested pipeline is filled middle helium, reach as high as pipe design pressure according to its pressure of condition, half of frock links to each other with corrugated tube by X-over, and corrugated tube is linked leak locator.Two body portion of frock are closed in detected weld place symmetry, stick with paste sternly in the junction with vacuum cement is careful, that opens leak locator slightly takes out valve, very little space with the sealing that forms between frock and the pipeline, be evacuated, after vacuum reached requirement, leak locator just can be worked and be begun leak detection.Generally need about 5 minutes to pulling down the process at one weld seam of detection again from installing to leak detection, very convenient.

Claims (1)

1. a cryogenic piping weld seam leak detection tool equipment includes frock main body and X-over, it is characterized in that: described frock main body: include body, the body two ends are welded with interior annulus respectively, and described interior internal radius is less than internal diameter of tube body; Be welded with the short tube of a UNICOM on the tube wall, described body cuts vertically, and the frock main body is divided into two parts; Described X-over includes the Quick Release Hoop that an end and leak locator are connected fast, the other end of Quick Release Hoop is provided with external thread, external thread screw togather outward have central openings, front end have in the ring edge swivel nut, be provided with packing ring between the front end face of ring edge and Quick Release Hoop in the described swivel nut, described short tube is plugged in the other end of described Quick Release Hoop, and fastening by swivel nut.

Images