The core of winter construction for JRPP (reinforced polypropylene) pipes lies in avoiding low-temperature brittleness, ensuring fusion quality, and implementing effective anti-freezing and protective measures. Below are the key considerations by phase, balancing material properties and construction standards.
1. Pre-construction Preparation
Material Storage and Preprocessing
Pipes and fittings should be stored in warehouses or simple sheds, avoiding exposure to freezing temperatures and direct sunlight outdoors. The stacking height should be ≤1.5m to prevent deformation from heavy pressure. Do not throw, drop, roll, or drag during handling to avoid hidden damage.
If there is a significant temperature difference between the site and the storage location, place the pipes and fittings at the site for more than 24 hours before installation to allow their temperature to approach the construction environment, thereby reducing potential connection hazards caused by thermal expansion and contraction.
Before construction, inspect each pipe individually and remove those with stress-induced whitening, scratches, or internal wall damage to eliminate hidden defects.
Environmental and Personnel Control
When the ambient temperature falls below 5°C, warming and insulation measures (such as building insulated sheds or using air heaters) must be taken. Below 0°C, outdoor construction should be minimized, and operations must be suspended during rainy, snowy, or windy weather to prevent joint moisture or brittle cracking of pipes.
Construction personnel must undergo specialized training to become familiar with the adjustment of hot-melt/electric-melt parameters and emergency handling procedures at low temperatures.
Preparation of Tools and Auxiliary Materials
Inspect specialized tools such as hot melt/electric melt welders and cutting machines to ensure they are functioning properly. Prepare auxiliary materials including anhydrous ethanol, fine sandpaper, insulation materials, and sand.
Prepare windproof, rainproof, and thermal insulation facilities, such as thermal blankets and tarps, to avoid interference from environmental factors during the welding process.
II. Construction Process Control
(1) Cutting and Preprocessing
Use a dedicated pipe cutter (≤40mm) or a rotary cutting machine (>40mm) to make vertical, slow cuts. After achieving a smooth cut, remove burrs and rough edges with fine sandpaper. Avoid using hacksaws or gas cutting to prevent cracking or deformation of the cut.
If stress whitening is observed at the pipe end before cutting, discard it immediately. Before connecting, wipe the pipe and fitting connection surfaces with anhydrous ethanol to remove oil stains and dust. When performing electrofusion connection, scrape off the 0.1-0.2mm oxide layer on the pipe surface.
Mark the hot melt insertion depth to ensure proper connection.
(2) Fusion Welding Construction (Core Process)
Connection Method Low-Temperature Adjustment Points Operation Specifications
Hot melt connection Temperature 260±10°C; heating time extended by 50% when ambient temperature <5°C Insert the heating sleeve/header to the marked depth without rotation, then quickly straight-line对接 without rotation after heating. Cooling period (typically ≥30 seconds) prohibits movement, rotation, or pressure application
Electrofusion Connection Adjust the heating time according to the manufacturer's parameters, and extend it appropriately at low temperatures. Keep the fusion surfaces dry. Straighten the coaxial alignment, connect the power supply for heating, and stop immediately when the signal eye shows molten material overflowing. During the cooling period,严禁外力干扰 (strictly prohibit external interference)
(3) Installation and Fixation
Installed pipelines are strictly prohibited from being struck or subjected to heavy pressure. Insulating cotton or protective sleeves must be used to cover overhead or vulnerable sections prone to external forces.
For long-distance laying, thermal expansion allowances must be reserved by installing expansion joints or natural compensation sections (such as L-shaped bends) to mitigate low-temperature shrinkage stress.
The spacing of supports and hangers shall be set according to the specifications to prevent pipe sagging or vibration; metal sleeves shall be installed when crossing walls or foundations, with insulation material filled between the sleeves and pipes.
3. Pressure Testing and Backfilling / Protection
hydrostatic test
Pressure testing is required after installation, backfilling, or before concealed laying: The test pressure for cold water pipes shall be 1.5 times the working pressure and ≥0.9MPa, while for hot water pipes, it shall be 2 times the working pressure and ≥1.2MPa. Maintain the pressure for 30 minutes; the pressure drop must be ≤0.05MPa with no leakage to be considered qualified.
After pressure testing, immediately drain the accumulated water in the pipes to prevent freezing, expansion, and cracking. For pipelines that will be left unused for an extended period without reliable insulation, the remaining water must also be drained.
Backfilling and Frost Protection
When backfilling buried pipelines, first fill with sand or fine soil with particle size ≤12mm up to 0.3m above the pipe top, compact it, and then backfill with the original soil to avoid sharp or hard objects scratching the pipe wall.
Exterior exposed pipes must be wrapped with specialized insulation sleeves or thermal insulation cotton, with additional thickened protection for exposed joints. Buried pipelines must meet the design requirements for burial depth, ensuring sufficient backfill thickness to prevent freezing.
IV. Safety and Finished Product Protection
Open flames are strictly prohibited at the construction site. Do not use open flames to bake pipes and fittings to prevent material deterioration or safety hazards.
After concealed installation, mark the pipeline routes to avoid damage during secondary renovations; place warning signs on completed pipelines to prevent stepping on or collision.
Establish a construction ledger to record environmental temperature, welding parameters, pressure test results, and other data for easy traceability and inspection.
V. Emergency Handling
If leakage is found at the joint after fusion, the joint must be cut off and refused. Repairing at the original joint location is strictly prohibited.
In case of sudden temperature drop, immediately suspend construction, cover installed pipelines with insulation materials, drain accumulated water inside the pipes, and resume work only after temperatures rise and warming measures are implemented.
As the year draws to a close, we set our sights on new beginnings. Today, Qingdao Laoshan Tube Industry Technology Co., Ltd. held a grand year-end summary meeting for 2025 in the company's third-floor conference room. All employees gathered together to review the year's achievements and discuss the development blueprint for 2026. Department heads delivered speeches in turn, followed by remarks from employee representatives, management team leaders, and General Manager Gu. The entire meeting was marked by a warm, practical, and efficient atmosphere, fostering a strong consensus of "gratitude, progress, breakthroughs, and innovation.". Departmental Performance Reports: Addressing Shortcomings in Our Roles, Focusing on Goals for Development The sales department stated in its remarks that it will focus on the core of "service" and clarify the work direction for 2026: "The sales team will always prioritize customer service, adhering to the pragmatic spirit of 'doing more with more effort.' We will actively engage with market demands, enhance customer satisfaction through meticulous and thoughtful service, and secure more collaboration opportunities with integrity and professionalism." The straightforward words reflect the sales team's determination to conquer the market. As the years roll on, looking back at the entire year, the customer service center has consistently upheld its original commitment of "thinking as the customer thinks and acting as the customer acts." With perseverance that "fears not the long and arduous journey" and a sense of responsibility that prioritizes "doing," it has delivered impressive results. We jointly reviewed the financial department's performance throughout the year. Throughout this year, we steadfastly adhered to the service philosophy of "centering on business, addressing its needs, and prioritizing its urgency." With unwavering patience and meticulous effort—"fearless of complexity and triviality"—we delivered a rigorous, standardized, and robust financial report through pragmatic action and precise execution. The speech by the warehousing and logistics department focused on "standardization" and "quality improvement with efficiency enhancement." It mentioned that by 2025, warehouses had achieved certain results in "accounting consistency" and standardized picking and shipping, but issues such as insufficient work motivation and lack of innovation still persisted.
Question 1: In which aspects does Qingdao Laoshan Pipe Industry Technology Co., Ltd.'s core competitiveness manifest? The core competitiveness primarily encompasses three aspects: First, technological and craftsmanship advantages—having dedicated over three decades to the industry, integrating traditional manufacturing wisdom with modern technology to achieve an upgrade from semi-automation to intelligent production, while standing as a "specialized, refined, distinctive, and innovative" enterprise with profound technological expertise. Second, product advantages—products span multiple pipeline series, featuring green environmental protection, safety, non-toxicity, and durability, with some products lasting up to 70 years, meeting diverse needs. Third, brand and reputation advantages—having won honors such as "Qingdao Premium Product" and "Famous Trademark of Shandong Province," the company has established itself as a renowned industry hallmark through superior quality and exceptional service. Question 2: What significant recognition did Qingdao Laoshan Pipe Industry receive in 2024? What other core honors does the company hold? In 2024, the company was included in the second batch of "Qingdao Premium Products" with its "Laoshan Water Supply and Drainage Pipe Materials." In addition, the enterprise was honored as a "Specialized, Refined, Distinctive, and Innovative Enterprise" and a "Demonstrative Specialized, Refined, Distinctive, and Innovative Enterprise in Qingdao," as well as awarded core honors such as "Famous Trademark in Qingdao," "Famous Trademark in Shandong Province," and "China Famous Brand.". Question 3: What are the future development priorities and goals of Qingdao Laoshan Pipe Industry Technology Co., Ltd? Key Development Priorities: 1. Increase R&D investment, deepen industry-university-research collaboration, focus on cutting-edge fields such as new materials, intelligence, and green environmental protection, and drive pipeline technology iteration. 2. Strengthen full-process quality management, implementing refined control over raw materials, production, and installation services. Development Goals: To provide global clients with superior, intelligent, and environmentally friendly pipeline solutions。
Winter Construction Precautions for JRPP Low Temperature Impact: JRPP (jointless reinforced plastic pipe) materials may become brittle at low temperatures, increasing the risk of cracking during transportation, handling, and installation. Pre-construction Inspection: Check pipes and fittings for any signs of damage, such as cracks, dents, or deformation caused by cold weather. Thawing Requirements: If materials are frozen or covered with ice, allow them to thaw naturally in a protected environment before use. Installation Temperature: Avoid installing JRPP when ambient or ground temperatures are too low (follow manufacturer recommendations, typically above 0°C or as specified). Trench Preparation: Ensure trenches are free of frozen soil, ice, or snow. Frozen subgrade should be removed and replaced with suitable backfill material. Backfilling: Use granular, unfrozen backfill material. Avoid using frozen clods or large ice chunks, which can cause uneven settlement and damage to the pipe. Sealing and Connection: Pay special attention to joint sealing. Cold temperatures can affect the performance of adhesives or sealing materials; use products suitable for winter conditions. Protection After Installation: Cover exposed pipes to prevent freezing and damage from construction activities. Product Storage Issues in Winter Storage Environment: Store JRPP in a dry, covered area protected from direct sunlight, rain, snow, and extreme cold. Avoid leaving materials outdoors for extended periods. Temperature Control: If possible, maintain a moderate storage temperature to prevent material embrittlement. Avoid storing near heat sources that could cause thermal stress. Stacking and Handling: Use proper stacking methods to prevent deformation. Avoid dropping or rough handling, as low temperatures increase the risk of cracking. Packaging Protection: Keep original packaging intact to protect against moisture and physical damage. Inventory Management: Rotate stock to ensure older materials are used first, reducing the risk of degradation from long-term winter storage. Risk Mitigation and Recommendations Develop a winter construction plan specific to JRPP, including temperature monitoring and material handling procedures. Train construction personnel on winter installation techniques and the proper use of cold-weather compatible adhesives and sealants. Maintain close communication with suppliers to ensure materials are shipped and stored under appropriate conditions. Conduct regular inspections of stored and installed materials to identify potential issues early. By following these precautions and addressing storage issues, the performance and longevity of JRPP in winter construction projects can be significantly improved.
Company:3999 Yingliu Road, FAW Industrial Park, Jimo District, Qingdao
24-hour free service call: 400-626-7878
Tel:400-626-7878
E-mail: laoshanpipe@163.com
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