Current Status and Market Use of Galvanized Threaded Steel Pipe

One. Classification of corrugated culvert:

Corrugated Culvert Pipe can be roughly classified from the following three aspects:

1. According to the number of layers, it can be divided into single-layer metal corrugated culverts and double-layer metal corrugated culverts. Single-layer corrugated culverts have superior impact resistance and compression resistance, while double-layer corrugated culverts have lower stiffness than single-layer corrugated culverts. some. But no matter how it is classified, the quality of metal corrugated culverts is well known.

2. From the classification of forming process, metal corrugated culvert can be divided into rolling forming, hydroforming mode, deposition forming and welding forming and other metal corrugated culverts. These are all derived from the good plasticity and toughness of metal corrugated culverts. The advantage is that the corrugated culvert is designed into corrugated culverts of different shapes suitable for use, and the performance and functions of the metal corrugated culverts pressed by different methods are also different.

3. According to the use of welded metal corrugated culvert, it can be roughly divided into airtight and watertight type and winding type. Air-tight and water-tight is a metal corrugated culvert specially used to transport gas or water heaters. It has good airtightness and can avoid air leakage and water leakage. The coiled metal corrugated culvert is mostly used as corrugated culvert for magnetic card telephones or desk lamps. The safety of this kind of corrugated culvert is very high;

Corrugated Culvert Pipe

Two, the use of corrugated culvert

Although metal corrugated culvert pipe has many advantages, if it is installed improperly or used unreasonably, it will not be able to achieve the desired effect and even bring about economic losses. The following items must be paid attention to when using or modifying:

1. To prevent the metal corrugated culvert from being subjected to torsion and shearing force, special attention should be paid when screwing the joint nut.

2. Reasonably select the actual bending radius R. R can be selected as follows: R=KRmin. Allowable minimum bending radius for corrugated culvert. K is the empirical coefficient. If the K value is selected too small, the hose diameter will be repeatedly bent, which is prone to fatigue failure and stress concentration; if the K value is too large, it will cause material waste and difficulty in layout. Generally selected in the range of 1~2.2.

3. In the process of use, ensure that the hose braided mesh sleeve is not mechanically damaged by knocks, bumps, abrasions, and bumps.

4. Correctly choose the nominal length L of the metal corrugated culvert. The price of corrugated culvert is higher. If the length is too long, it will increase unnecessary investment, increase flow resistance, and may cause additional vibration. However, if the length is not enough, it is easy to bend at the joint welding seam, and the metal corrugated culvert cannot work in the natural bending state, and the service life will be shortened. For the metal corrugated culvert configured with two parallel sections moving longitudinally, it should be determined as follows: L=4R ten 0.5S+△ where: R is the actual bending radius of the hose; S is the distance between the opening and closing positions of the hot plate ;△The height difference between the opening and closing position of the hot plate and the fixed joint end of the hose. Obviously, the fixed end of the metal corrugated culvert is set at the center height of the opening and closing position of the pressure plate, and L is the shortest.

Third, the advantages of prestressed metal corrugated culvert

1. Prestressed metal corrugated culvert pipe adopts double threads, and its performance indexes such as strong rigidity are better than single thread. 2. Good adhesion to concrete, strong engineering adaptability. It can ensure that the steel strand ducts have good quality, achieve straight straight lines and smooth curves. For the long steel bundles of long-span bridges, its superiority is more prominent.

3. The pipe friction loss is small. Because the prestressed metal corrugated culvert pipe is in point contact with the steel strand, the friction coefficient and deviation coefficient of the pipe are small, thereby reducing the friction loss and increasing the effective prestress. After many tests, the friction coefficient between the steel strand and the pipe wall is 0.16~0.22, with an average of 0.19; the deviation coefficient k value is (0.6~1.0)x10-sl. , The average is o. 8x10 a 3Zm.

4. The pre-stressed metal corrugated culvert has high work efficiency and significant economic benefits. The use of corrugated culvert pipes can ensure the quality of the project, and is easy to operate, easy to wear, can shorten the construction period, save investment, and have significant economic benefits.