HDPE Krah Pipe

product details

HDPE Krah pipe (Type B wound structural wall pipe) is manufactured via a hot winding process using high-quality HDPE. The spirally wound profiled wall structure achieves ring stiffness up to SN32, making it ideal for large-diameter, deep-buried and heavy-duty drainage applications.

Corrosion-resistant, UV-stable and non-scaling, the pipe ensures efficient sewage and stormwater flow. Joints are welded using electrofusion belts to form a monolithic, fully sealed connection with zero leakage, eliminating groundwater contamination. Available in diameters from DN300 to DN4000, the pipe weighs only about 1/5 of equivalent concrete pipes, facilitating transportation and installation.

It is commonly used in municipal trunk sewers, urban stormwater culverts, industrial park drainage, sponge city projects, tunnel drainage, river remediation and pump station networks, as well as trenchless pipe jacking and rehabilitation.

Item	HDPE Krah Pipe (Wound Structural Wall)
Material	HDPE
Standard	GB/T 19472.2
Common Size (DN/mm)	DN200 to DN3000
Pressure / Stiffness	SN4 to SN12.5
Connection	Electrofusion Belt Connection
Application	Municipal trunk lines, stormwater culverts, trenchless pipe jacking, tunnel drainage
Key Advantages	Ultra-high ring stiffness, heavy duty, large diameter, zero leakage

Nominal Diameter DN (mm)	Minimum Average Inner Diameter (mm)	Minimum Inner Wall Thickness (mm)	Common Ring Stiffness Grades	Application Scenarios of Ring Stiffness	Recommended Usage
200	195	1.5	SN4, SN8	SN4: Shallow drainage for green belts; SN8: Branch pipes for residential areas	Rainwater and household branch pipes for residential areas
300	294	2	SN4, SN8, SN12.5	SN8: General municipal engineering; SN12.5: Pipes passing under roads	Common branch pipes for residential and municipal projects
400	393	2.5	SN8, SN12.5, SN16	SN8: Auxiliary roads; SN12.5: Main roads; SN16: Heavy loads	Mainstream pipes for municipal rainwater and sewage
500	492	3	SN8, SN12.5, SN16	Buried in municipal roads and highways; Medium-deep burial	Main sewage pipes for urban areas
600	591	3.5	SN8, SN12.5, SN16	Main roads; Underpassing roads; Main pipes in industrial parks	Main drainage pipes for urban areas
800	789	4	SN12.5, SN16, SN20	Main roads; Deep burial; Underpassing highways	Main drainage pipes for urban areas
1000	987	5	SN12.5, SN16, SN20	High cover depth; Main roads; Heavy-load sections	Main sewage pipes in urban cores
1200	1185	5	SN16, SN20	Deep burial; Expressways; Large-scale municipal projects	Main flood relief pipes in cities
1500	1483	6	SN16, SN20	Deep and high burial; Key projects with high load	Main flood relief pipes; Large-scale water system networks
1800	1785	6	SN16, SN20	Extra-deep burial; Key national highway projects	Main flood drainage pipes in urban areas
2000	1985	6	SN16, SN20	Extra-heavy loads; Extra-large drainage projects	General flood control and drainage pipes in cities
2500	2480	8	SN20	Ports; Large-scale flood control; Special projects	Special large-diameter flood relief pipes
3000	2975	10	SN20	Customized extra-large heavy-duty flood control projects	Special large-diameter flood relief projects

Notes on pipelines：

1. Suitable for large-diameter, deep-buried and heavy-duty drainage projects, select ring stiffness (SN16-SN32) according to geological conditions and buried depth.

2. Use electrofusion belt for joint connection, operate in strict accordance with the welding process, ensure the welding surface is clean, and conduct sealing test after welding to achieve zero leakage.

3. The trench must have a solid bearing foundation, soft soil layer needs to be reinforced to prevent uneven settlement causing pipeline fracture and dislocation.

4. During hoisting and handling, use special spreaders, prohibit single-point hoisting and violent collision, avoid damage to the spiral winding structure of the pipe wall.

5. When carrying out non-excavation pipe jacking construction, control the jacking force evenly, avoid excessive local stress causing pipe deformation.

6. Backfill in strict accordance with construction specifications, symmetrically layered tamping, prevent partial pressure from damaging the pipeline; regular inspection of pipeline settlement and deformation.