HDPE排污用中空壁缠绕管六种连接方式

　　在我国生产中空壁缠绕管的有关企业通过和用户的密切合作，已经开发出多种连接方法，以适应各种不同工程的需要。以下介绍的6种常用的连接方法，都有优缺点和适用的场合，用户可以根据工程不同的要求和条件选择。例如，有些连接方法用人工较多，施工比较费时间，比较适合于劳动力比较低廉的地区。

挤出熔料焊接

　　挤出熔料焊接就是用手持的焊枪挤出熔融的聚乙烯料，将连接缝两侧的聚乙烯熔接起来。通常采用内外双面焊接，适于内径800mm以上的管材，工人可以进入管内焊接。这一方法的优点是：保证密封不泄漏、连接比较方便和灵活、施工工具简单（只要焊枪和电源）以及材料成本低。缺点是用人工较多，施工比较费时间。

卡箍加密封带连接

　　卡箍加密封带连接就是用剖分的金属卡箍（由对半分的两件组成，大直径可以用4分的4件组成）将待连接的两个管段从外圆周箍在一起。卡箍上做有凸起或弯边，通过卡住相邻的凸棱，可使待连接的两个管段在轴向也被固定住。卡箍和管材之间加一层弹性密封带，并在中空壁缠绕管螺旋槽的断头接缝两端塞上弹性密封块，依靠卡箍的锁紧张力压紧弹性密封带和弹性密封块来实现连接的密封要求。该方法的优点是：连接方便灵活、现场条件适应性强、施工工具简单（只需手工工具）以及人工费用少。缺点是密封可靠性较低，只适合用于排雨水管。

热收缩套（带）连接

　　热收缩套（带）连接用的材料是聚乙烯套（带）和增强纤维网。连接前，经过电子加速器辐射，使聚乙烯交联后再经过加热扩张和冷却定型，同时在管道内壁涂热熔胶。连接施工时，将热收缩套（带）套在待连接管段的接缝处，通过喷灯加热使其收缩，与内壁热熔胶熔接，形成密封好且有一定强度的连接接头。该方法的优点是：连接比较容易、施工工具简单（只要喷枪，不需要电源）且材料成本较低。缺点是用人工较多。

电热熔带连接

　　电热熔带连接用的是专门制作的电热熔带。本体是聚乙烯的电热熔带，其内表面嵌有电热丝，通电后，电热熔带内表面熔融，从而与波纹管的沟槽熔接。连接时，先把一段电热熔带缠绕并拉紧在接缝前的波纹沟槽内，通电使电热熔带内表面熔融，以与中空壁缠绕管的沟槽熔接，电热熔带没有覆盖到的轴向接缝要用挤出熔料焊接。如有必要，在管道内再进行一次挤出熔料焊接。

平直管端用剖分卡箍连

　　这是指在中空壁缠绕管的螺旋端口焊接上特制的聚乙烯连接构件（在制造工厂内完成），此构件可将螺旋端口转化为有锥形凸缘的平端。在铺设现场，用有锥形凹槽的剖分卡箍将两管段的锥形凸缘夹紧连接，依靠凸缘端面间的密封胶圈保证密封。

平直管端用弹性密封圈的承插连接

　　弹性密封圈的承插连接是埋地排水管最常用也是最受用户欢迎的的连接方法，因为铺设时只要进行承插即可完成连接。 　

Through close cooperation with users, relevant enterprises producing hollow wall winding pipes in China have developed a variety of connection methods to meet the needs of various projects. The following six common connection methods have advantages, disadvantages and applicable occasions. Users can choose according to different requirements and conditions of the project. For example, some connection methods use more labor, and the construction is time-consuming, which is more suitable for areas with relatively low labor force.

Extrusion melt welding

Extrusion melt welding is to extrude the molten polyethylene with a hand-held welding gun and weld the polyethylene on both sides of the joint. Generally, internal and external double-sided welding is adopted, which is suitable for pipes with an inner diameter of more than 800mm. Workers can enter the pipe for welding. The advantages of this method are: no leakage of seal, convenient and flexible connection, simple construction tools (as long as welding gun and power supply) and low material cost. The disadvantage is that more labor is used and the construction takes more time.

Clamp encryption sealing belt connection

Clamp encryption sealing connection is to clamp the two pipe sections to be connected together from the outer circumference with split metal clamps (composed of two pieces in half, and four pieces in four for large diameter). The clamp is provided with a convex or curved edge. By clamping the adjacent convex edges, the two pipe sections to be connected can also be fixed in the axial direction. A layer of elastic sealing belt is added between the clamp and the pipe, elastic sealing blocks are plugged at both ends of the broken joint of the spiral groove of the hollow wall, and the elastic sealing belt and elastic sealing block are pressed by the locking tension of the clamp to meet the sealing requirements of the connection. The advantages of this method are: convenient and flexible connection, strong adaptability to site conditions, simple construction tools (only manual tools) and less labor cost. The disadvantage is that the sealing reliability is low and is only suitable for rainwater drainage pipes.

Heat shrinkable sleeve (belt) connection

The materials used for the connection of heat shrinkable sleeve (belt) are polyethylene sleeve (belt) and reinforced fiber mesh. Before connection, polyethylene is crosslinked by electron accelerator radiation, then heated, expanded and cooled, and hot melt adhesive is coated on the inner wall of the pipeline. During the connection construction, the heat shrinkable sleeve (belt) shall be sleeved at the joint of the pipe section to be connected, which shall be heated by a blowtorch to shrink and fused with the hot-melt adhesive on the inner wall to form a well sealed connection joint with certain strength. The advantages of this method are: easy connection, simple construction tools (as long as the spray gun, no power supply) and low material cost. The disadvantage is that more labor is used.

Electric melting belt connection

The electric heating melting belt is specially made for the connection of electric heating melting belt. The body is an electric heating melting belt of polyethylene, the inner surface of which is embedded with an electric heating wire. After power on, the inner surface of the electric heating melting belt melts, so as to weld with the groove of the bellows. When connecting, first wind and tighten a section of electric heating melting belt in the corrugated groove in front of the joint, and power on to melt the inner surface of the electric heating melting belt to weld with the groove of the hollow wall winding pipe. The axial joint not covered by the electric heating melting belt shall be welded with extruded melt. If necessary, perform another extrusion melt welding in the pipe.

Straight pipe ends are connected with split clamps

This refers to the welding of a special polyethylene connecting member (completed in the manufacturing plant) on the spiral end of the hollow wall wound pipe, which can convert the spiral end into a flat end with a conical flange. At the laying site, the conical flanges of the two pipe sections are clamped and connected with the split clamp with conical groove, and the sealing is ensured by the sealing rubber ring between the flange end faces.

Socket connection of elastic sealing ring for straight pipe end

The socket connection of elastic sealing ring is the most commonly used and popular connection method for buried drainage pipes, because the connection can be completed as long as the socket is installed during laying.