Introduction to KRAH pipe

What is KRAH pipe? KRAH pipe is high-density polyethylene structural wall thermal winding pipe, HDPE winding structural wall pipe, it is a new type of special-shaped structural wall pipe, made of high-density polyethylene thermal winding molding process. KRAH pipe products are mainly high-density polyethylene resin (HDPE) as raw material, with PP or PE corrugated pipe as auxiliary support pipe, high-density polyethylene large-diameter winding reinforced pipe produced by thermal winding molding process. Because this kind of pipe was originally introduced from the German KRA Company by a domestic company, it is commonly known as KRAH pipe in China. The official name of this kind of pipe in China is: high-density polyethylene structural wall thermal wound pipe, the national standard is GB/T 19472. 2-2004 B-type structural wall pipe. The KRAH pipe product is an environmentally friendly and safe product with the advantages of light weight, strong pressure bearing capacity, high interface quality, long life, corrosion resistance, high ring stiffness, and convenient construction. It is widely used in urban water supply, drainage, long-distance Water delivery and farmland irrigation and other projects. The diameter of the pipe is from DN300-DN4000. The pipe material is light in weight and has good overall flexibility. It is the main pipe material of choice for buried sewage and drainage.

KRAH pipe standards and specifications

KRAH pipe standard

1. Executive standard: German DN16961 standard, GB/T19472.2-2004, CECS164:2004, GB50268-2008

2. KRAH pipe product specifications (mm): DN300, DN400, DN500, DN600, DN700, DN800, DN900, DN1000, DN1100, DN1200, DN1300, DN1400, DN1500, DN1600, DN1700, DN1800, DN1900, DN2000, DN2200, DN2400, DN2500, DN2600, DN2800, DN3000

3. KRAH pipe ring stiffness: up to 20KN/m2 (according to user needs, SN8; SN10; SN12.5; SN16), and the depth of covering soil can reach 20m.

4. The internal pressure level of KRAH pipe: 0.3MPa, the maximum pressure can reach 0.45Mpa.

5. KRAH pipe flexibility: 183m can be coiled into a circle.

KRAH pipe product classification

KRAH pipe products can be divided into three series: PR, OP, SQ, VW, among which: PR, OP-mainly used for buried drainage pipes, SQ-mainly used for making containers or manholes, VW-mainly used for tee, bend The most widely used products are the PR series. The product has a smooth inner surface and a special-shaped reinforced structure on the outside. The standard length of the pipe is 6 meters, and the inner diameter of the pipe ranges from DN300 to DN4000. The product indicators all reach GB /T 19472. 2-2004 B-type structural wall pipe standard and PREN-13476 European standard requirements.

Four, KRAH pipe performance characteristics

The performance characteristics of HDPE winding structure wall pipe (KRAH pipe) are as follows:

1. The quality of the hot winding seam is good

The flat material strips and U-shaped material strips extruded from the die of the extruder in the molten state are evenly wound on the heated drum mold according to the predetermined position, which ensures the quality of the welded seam of the structural wall pipe. Especially in the structural design, the welded seam of the flat material belt is covered by the polyethylene-coated support pipe, which improves the overall external pressure resistance of the product.

2. Excellent installation performance

The pipe connection adopts the socket electric fusion connection technology of the same material as the electric fuse embedded in the socket, and the connection quality is high. It can be 100% leak-free, ensuring the same life of the pipeline system and the safety of operation. At the same time, because the product is lighter than other pipes under the same application conditions, it is easy to transport, convenient and quick to construct, and can reduce construction costs. , Basically, it is done while excavation, pipe down, and backfilling, which simplifies the construction procedure and shortens the construction period. In the acceptance of the project, the closed air test is used instead of the closed water test, which not only speeds up the acceptance speed, but also saves the complicated work and a large amount of test costs in the closed water test.

3. Good flexibility

The high-density polyethylene winding structure wall pipe has good flexibility on the macro level, and the local pipe section has strong rigidity and overall external pressure resistance, which can ensure the safety of traffic when used under the road with overweight load. Due to the flexibility of the pipe, the damage and loss of the pipe can be minimized in the event of geological activities such as earthquakes and uneven settlement on the surface, thereby improving the ability of public facilities to resist earthquakes and reduce disasters.