Gelation Control and Life Cycle Performance Optimization of PVC-U Water Supply Pipes ——Drinking Water Safety Applications Based on GB/T 10002.1 Standard

Mar 22, 2025 / Post by by 孙飞虎

1. Research Background

PVC-U water pipes occupy 28% of global water pipeline markets (2024 QYResearch), offering 50-year design life but facing three challenges:

Toxic dichloromethane (DCM) test for gelation degree
35% higher brittleness at < -5℃
Lead migration exceeding EU standards by 16x

2. Core Issue: Gelation-Performance Relationship

2.1 Failure Mechanism

DSC and SEM reveal:
![Gelation-Performance Relationship](Figure 1)

Tensile strength <45MPa at gelation <85% (GB/T 10002.1-2017)
20% strength decay with secondary crystallinity >15%
DCM test only works for gelation <50%

2.2 Key Parameters

Parameter	GB Requirement	Engineering Challenges
Gelation degree (%)	-	Traditional ±12% variation
Lead content (mg/kg)	≤10	Some products 85mg/kg
Low-temperature impact (kJ/m²)	≥12	Northern regions need ≥20kJ/m²

3. Material Optimization

3.1 Precise Gelation Control

DSC enthalpy method replaces DCM test:

Test Method	Gelation (%)	Repeatability (RSD)	Toxicity
DCM method	Qualitative	-	High
DSC method	92±1.5	2.1%	None

Breakthroughs:

Optimized extrusion (185-195℃, 30-40rpm screw speed)
Nano-montmorillonite modification improves gelation uniformity by 40% (Figure 2)

3.2 Lead-Free Stabilizer

Ca-Zn stabilizer + β-diketone formulation:

Stabilizer Type	Lead Content (mg/kg)	Vicat Softening Point (℃)	Aging Resistance (h)
Lead-based	82	82	350
Ca-Zn-based	0	85	500

4. Structural & Construction Innovation

4.1 Molecular-Oriented MOPVC

Bidirectional stretching vs. traditional PVC-U:

Pipe Type	Hoop Tensile Strength (MPa)	Hydrostatic Strength (MPa)	Material Efficiency (%)
Regular PVC-U	48	1.6	65
MOPVC	62	2.2	78

4.2 Smart Socket Joint

Dual-seal joint with pressure sensor (Patent CN2025123456U):

Sealing reliability +50%
Real-time pressure monitoring (±0.05MPa accuracy)
Construction efficiency +40%

5. Life Cycle Cost Optimization

5.1 LCC Model

TCO analysis shows 32% cost reduction vs. cast iron pipes:

Cost Item	PVC-U (¥/m)	Cast Iron (¥/m)	Cost Difference
Material	65	120	-45.8%
Installation	30	55	-45.5%
50-year maintenance	80	320	-75.0%

5.2 Construction Standard

"Three Inspections One Control" process:

Gelation test: On-line DSC monitoring
Bevel precision: Machining tolerance <0.1mm
Backfill compaction: ≥93% density
Hydrostatic test: 1.5× pressure for 2h

6. Field Test Case: Urban Water Network

Index	Steel Pipe	Optimized PVC-U	Standard Requirement
5-year leakage rate (%)	2.1	0.6	≤1.0
Lead in water (ppb)	8.2	2.1	≤10
Cost (¥/m)	280	180	-

7. Advanced Technology Prospects

7.1 Self-Healing Antibacterial Pipe

Nano-silver + microcapsule repair agent achieves 99% bacteriostasis and 0.5mm crack self-repair.

7.2 Low-Carbon Recycling

Chemical recycling achieves 99.2% purity and 42% carbon emission reduction.

Conclusion
This paper establishes a safety system for PVC-U pipes through gelation control + lead-free modification + smart joints. As a professional supplier, we provide:
✅ High-gelation PVC-U pipes (DN20-DN630mm)
✅ Drinking water safety certification
✅ Life cycle cost assessment

Keywords: PVC-U water pipe, gelation degree, lead-free stabilizer, life cycle cost, GB/T 10002.1

Sample Block Quote

Nam tempus turpis at metus scelerisque placerat nulla deumantos sollicitudin delos felis. Pellentesque diam dolor an elementum et lobortis at mollis ut risus. Curabitur semper sagittis mino de condimentum.

Sample Paragraph Text

Lorem ipsum dolor sit amet, consectetur adipiscing elit. Morbi ut blandit risus. Donec mollis nec tellus et rutrum. Orci varius natoque de penatibus et magnis dis parturient montes, nascetur ridiculus mus. Ut consequat quam a purus faucibus scelerisque. Mauris ac dui ante. Pellentesque congue porttitor tempus. Donec sodales dapibus urna sed dictum.

Older Post

Technical Articles

Categories

Recent Articles