Due to the non conductivity and non magnetism of the PE pipe, it is not possible to track the PE pipe, which will bring inconvenience to future pipeline maintenance. The gas tracing line effectively solves the problem of non-metallic pipelines that cannot be detected using metal pipeline detectors.

《城鎮燃氣輸配工程施工及驗收規范》CJJ33-2005第7.2.9條規定：聚乙烯燃氣管道敷設時，應在管頂同時隨管道走向敷設示蹤線，示蹤線的接頭應有良好的導電性。

Article 7.2.9 of the "Code for Construction and Acceptance of Urban Gas Transmission and Distribution Engineering" CJJ33-2005 stipulates that when laying polyethylene gas pipelines, tracer lines should be laid at the top of the pipeline along with the pipeline direction, and the joints of the tracer lines should have good conductivity.

一、示蹤線的作用

1、 The role of tracer lines

“示蹤線”用于對PE管道的探測、追蹤及定位。“示蹤線”同PE管一起鋪設；一般會采用金屬線芯，通過探測設備給“金屬線”施加信號，由探測接收機接收信號，從而找到示蹤線的準確位置，即同步追蹤到PE燃氣管道的具體位置；以便于對PE管道進行改造及維修。

The "tracer line" is used for detecting, tracking, and locating PE pipelines. The "tracer line" is laid together with the PE pipe; Generally, metal wire cores are used to apply signals to the "metal wire" through detection equipment, and the detection receiver receives the signal to find the accurate position of the tracer line, that is, to synchronously track the specific position of the PE gas pipeline; To facilitate the renovation and maintenance of PE pipelines.

二、示蹤線的發展

2、 Development of Tracer Lines

代示蹤線：是由鋁箔和塑料薄膜的母體組成，鋁箔主要是傳輸信號，母體是固定鋁箔。這種示蹤線缺點：鋁箔強度非常低，即使在生產，運輸過程中也很容易斷裂，輔設易損傷，同時鋁箔的電阻非常大，有效探測距離和深度有限。

The first generation tracer line is composed of a matrix of aluminum foil and plastic film. The aluminum foil mainly transmits signals, while the matrix is fixed aluminum foil. The disadvantage of this tracer line is that the strength of aluminum foil is very low, and even during production and transportation, it is easy to break, and the auxiliary equipment is easily damaged. At the same time, the resistance of aluminum foil is very high, and the effective detection distance and depth are limited.

第二代示蹤線：是由鋼絲和塑料薄膜壓制而成，該示蹤線由鋼絲為導體，電阻大，探測距離有限，難以滿足實際需要。

The second generation tracer line is made by pressing steel wire and plastic film. The tracer line is made of steel wire as the conductor, with high resistance and limited detection distance, making it difficult to meet practical needs.

第三代示蹤線：是由銅包鋼金屬線芯和PE外保護層組成，外觀成線狀。

The third generation tracer wire: It is composed of a copper clad steel metal wire core and a PE outer protective layer, with a linear appearance.

三、示蹤線鋪設注意事項

3、 Precautions for laying tracer lines

、蹤線埋設時應緊貼PE管道呈直線狀，并位于管道的頂面為好。請勿以螺旋狀纏繞在PE管道上埋設，這樣易導致探測結果不準確。

When burying the trace line, it should be closely attached to the PE pipeline in a straight line shape and located on the top surface of the pipeline. Do not bury PE pipes in a spiral shape, as this may lead to inaccurate detection results.

在窨井或出地處示蹤線應該預留出一定長度的導線（1m以上為宜），供探測施加信號所用。這樣可提髙探測效率和精度。

A certain length of wire (1m or more is recommended) should be reserved for the tracing line in the inspection well or at the exit point, for the purpose of detecting and applying signals. This can improve detection efficiency and accuracy.

示蹤線接頭或分支點一定要連接牢固，保持良好導電,并用絕緣膠布包好，防止地下潮濕而造成腐蝕斷線情況，使探測信號中斷。管道的鋼塑轉換接頭處示蹤線可以焊接在法蘭上，接點處做好防腐處理，防止日久后腐蝕斷線。

The connector or branch point of the tracer line must be firmly connected, maintain good conductivity, and be wrapped with insulating tape to prevent corrosion and wire breakage caused by underground moisture, which may interrupt the detection signal. The tracing line at the steel plastic conversion joint of the pipeline can be welded to the flange, and the joint should be treated with anti-corrosion measures to prevent corrosion and wire breakage over time.

為增加示蹤線的信號強度并讓信號分布均勻，施工時須盡量減小示蹤線埋地末端的接地電阻，采取剝掉絕緣層裸露芯線30cm的良好接地措施。特別是對于長度較短的分支管的末端，一定要接地良好，否則分支上的信號會非常弱而探測不到。

To increase the signal strength of the tracer line and ensure uniform signal distribution, it is necessary to minimize the grounding resistance at the buried end of the tracer line during construction, and take good grounding measures by peeling off the insulation layer and exposing the core wire for 30cm. Especially for the ends of shorter branch pipes, they must be well grounded, otherwise the signal on the branch will be very weak and cannot be detected.

若管道埋地長度超過1km，中間又沒有窨井等設施供預留示蹤線頭滿足探測之需，則建議每處設一個測試樁并預留示蹤線接頭供探測時使用。

If the buried length of the pipeline exceeds 1km and there are no inspection wells or other facilities in the middle to reserve tracer heads to meet the detection needs, it is recommended to set up a testing pile at every kilometer and reserve tracer line joints for use during detection.

在非開挖工程施工中，PE管道外面的示蹤線在拖管過程中容易被扯斷，簡便的辦法是選擇截面積更大、強度更高的導線或鋼絲繩，或者在管道的內部預穿一條示蹤線即可避免斷線，其探測效果如同在外面一樣，但這樣做時需處理好內部示蹤線頭與外面示蹤線連接的問題。

In non excavation engineering construction, the tracer line outside the PE pipeline is prone to being torn during the dragging process. A simple method is to choose a larger cross-sectional area and higher strength wire or steel wire rope, or to pre thread a tracer line inside the pipeline to avoid wire breakage. The detection effect is the same as on the outside, but when doing so, it is necessary to handle the problem of connecting the internal tracer line head to the external tracer line.
在某些特殊情況下，對PE管道無法應用示蹤線，這時可采用預埋示蹤球的方法滿足今后的探測定位需要。

In some special cases, it is not possible to apply tracer lines to PE pipelines. In this case, the method of embedding tracer balls can be used to meet future detection and positioning needs.