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.

《城镇燃气输配工程施工及验收规范》CJJ33-2005第7.2.9条规定：聚乙烯燃气管道敷设时，应在管顶同时随管道走向敷设示踪线，示踪线的接头应有良好的导电性。

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、示踪线的作用

1、 The role of tracer lines

“示踪线”用于对PE管道的探测、追踪及定位。“示踪线”同PE管一起铺设；一般会采用金属线芯，通过探测设备给“金属线”施加信号，由探测接收机接收信号，从而找到示踪线的准确位置，即同步追踪到PE燃气管道的具体位置；以便于对PE管道进行改造及维修。

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、示踪线的发展

2、 Development of Tracer Lines

代示踪线：是由铝箔和塑料薄膜的母体组成，铝箔主要是传输信号，母体是固定铝箔。这种示踪线缺点：铝箔强度非常低，即使在生产，运输过程中也很容易断裂，辅设易损伤，同时铝箔的电阻非常大，有效探测距离和深度有限。

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.

第二代示踪线：是由钢丝和塑料薄膜压制而成，该示踪线由钢丝为导体，电阻大，探测距离有限，难以满足实际需要。

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.

第三代示踪线：是由铜包钢金属线芯和PE外保护层组成，外观成线状。

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、示踪线铺设注意事项

3、 Precautions for laying tracer lines

、踪线埋设时应紧贴PE管道呈直线状，并位于管道的顶面为好。请勿以螺旋状缠绕在PE管道上埋设，这样易导致探测结果不准确。

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.

在窨井或出地处示踪线应该预留出一定长度的导线（1m以上为宜），供探测施加信号所用。这样可提髙探测效率和精度。

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.

示踪线接头或分支点一定要连接牢固，保持良好导电,并用绝缘胶布包好，防止地下潮湿而造成腐蚀断线情况，使探测信号中断。管道的钢塑转换接头处示踪线可以焊接在法兰上，接点处做好防腐处理，防止日久后腐蚀断线。

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.

为增加示踪线的信号强度并让信号分布均匀，施工时须尽量减小示踪线埋地末端的接地电阻，采取剥掉绝缘层裸露芯线30cm的良好接地措施。特别是对于长度较短的分支管的末端，一定要接地良好，否则分支上的信号会非常弱而探测不到。

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.

若管道埋地长度超过1km，中间又没有窨井等设施供预留示踪线头满足探测之需，则建议每处设一个测试桩并预留示踪线接头供探测时使用。

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.

在非开挖工程施工中，PE管道外面的示踪线在拖管过程中容易被扯断，简便的办法是选择截面积更大、强度更高的导线或钢丝绳，或者在管道的内部预穿一条示踪线即可避免断线，其探测效果如同在外面一样，但这样做时需处理好内部示踪线头与外面示踪线连接的问题。

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.
在某些特殊情况下，对PE管道无法应用示踪线，这时可采用预埋示踪球的方法满足今后的探测定位需要。

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.