In the construction of water supply projects of modern rural construction, numerous problems frequently appear due to the restriction of site and environment.
In this article, HDPE pipe fitting suppliers summarize the following optimization tips to help you:
Optimization - Hot melt welding interface quality
Notes for hot melt docking:
(1) Must comply with the docking equipment operation procedures and precautions;
(2) Operators must wear gloves, wear work clothes, do a good job of self-protection, to avoid being electric shock or burns;
(3) The heating plate and the connecting end face of the connecting piece should be kept neat:
(4) The actual value of the docking pressure to be adjusted to the field connection:
(5) Polyethylene pipe can not use open flame heating;
⑥ Welding interface should be protected from sand and rain.
The following problems are likely to occur at hot melt welding joints:
There are some quality problems, such as the asymmetry of rolling edge, excessive amount of wrong edge, bubble sag and pitting on weld surface.
Analyze the reasons:
(1) Welded pipe specifications are different;
(2) Semi-automatic welding machine is used and welding is not performed according to the specified welding parameters, such as the dragging pressure of the welding machine is too large and the cooling time is too short;
(3) The performance of the automatic welding machine is not qualified;
(4) The parameter settings of the hot melt welder are not consistent with the characteristics of the pipe (PE pipes produced by different manufacturers have different properties (such as thermal stability)).
(5) Construction under humid and other bad weather conditions;
(6) The specified hot melt fixture and roller bracket are not used during welding, and the matching quality does not meet the requirements;
(7) Welding machine operator without professional training without license.
2. Optimize the welding quality of electric fusion connection
Electromelt connection is a welding method that is least affected by the external environment.
Electric fusion connection is to use a special electric fusion pipe with embedded resistance wire and the connection part of the pipe or pipe fitting close contact with electricity, through the embedded resistance wire heating connection part, so that it is fused together until the joint cooling. Electromelt connection can be used to connect polyethylene pipe or socket fittings of different types and different melt flow rates. Electromelt connection is divided into electromelt socket connection and electricity saddle connection.
The welding joint of electric hot melt welding is prone to the following problems: mainly "false welding".
Analyze the reasons:
(1) When connecting PE pipe, the special fixed fixture is not used to keep the two PE pipe interfaces "concentric", resulting in uneven interface clearance and reduced interface fusion area;
(2) There are compatibility problems between pipe and accessory devices. Pipe fittings and PE pipe are not from the same manufacturer.
(3) The removal of oxide layer is not implemented or the removal is uneven, resulting in unroundness at the end of PE pipe, resulting in uneven interfacial clearance and virtual welding;
(4) Moving the connector in the connection process;
(5) The melting cooling process is not carried out in a natural state, with water or forced air cooling;
(6) The length of the electromelt fitting inserted into the pipe is insufficient, which may cause swelling.
3. Optimize the quality of PE pipe and fittings
PE pipes and fittings are prone to the following problems:
As we all understand, PE is a highly common polymer material in life. The plastic bags used in shopping are made of PE plastic.
The advantages of PE pipe are extremely obvious compared with metal pipe, physical performance is extremely superior, PE pipe material is non-toxic, impact resistance, stress cracking resistance are excellent. PE pipe can be divided into three types: PE mine pipe, PE sewage pipe, PE water supply pipe.
Such problems are mostly caused by non-standard operations in the process of transportation and construction.
Here's why:
(1) After the excavation of the trench, it fails to backfill in time according to regulations, and is covered and soaked by construction waste and rainwater for a long time, which affects the operation safety and service life of the pipeline;
(2) In the process of transportation, handling and storage is not standardized operation, such as dragging and throwing PE pipe, resulting in pipe damage;
(3) The roller support is not used in the construction process, causing scratches on the PE pipe wall;
(4) Pipe placement problem: no shelter measures such as sun protection and rain prevention are taken to protect the pipe stored on site, which affects the service performance and shortens the service life of the pipe;
(5) The quality of pipes and fittings is not up to the requirements or expired pipes and fittings are used.
4. Alternative optimization directions
(1) The warning belt is not laid in the pipeline backfilling according to the regulations, and the trench depth is not up to the standard;
(2) Yellow sand and fine soil are not used as required to backfill PE pipelines. Compressed pipelines covered with stones or sharp objects are prone to air leakage at the interface, which gravely threatens the safe operation of pipelines in the future;
(3) The pipe opening is not blocked after the interruption of pipeline construction or the water is covered with soil during the construction backfilling process, which may cause a large amount of impurities and rainwater left in the pipeline and affect the safe and smooth operation of the pipeline in the future.