How to Install Krah Pipe?

Krah pipe (HDPE winding pipe) is a flexible pipe. The Krah pipe has the advantages of good connection tightness, strong anti-settlement ability and long comprehensive service life, and has been rated as the key promotion of green environmental protection pipe products by the ministry of municipal construction of China. 

Today we will talk about the installation process of the Krah pipe.

The installation and construction process of cladding pipe is as follows:

1. Excavating the canal trench of carats:

Net width of tank bottom: When the Krah pipe diameter is less than DN450mm, the net width of each side of the pipe is D+ 0.3m, and when the pipe diameter is greater than DN450mm, the net width of each side of the pipe is D+ 0.5m, and the outer diameter of the pipe should be 600mm, so that it is advisable to operate at the bottom of the pipe manually.

2. Lower groove of carat pipe:

1) The Krah pipe must be inspected in accordance with the product standards section by section before laying down the pipe. If it fails to meet the standards, laying down the pipe is strictly prohibited.

2) According to the diameter, groove and construction equipment, it is determined that the pipe shall be put into groove by human or machinery. Flexible and wide belt, sling or sling shall be used to lower the pipe, and the pipe shall not be directly hoisted by wire rope or chain. Stable ditch, not with the wall, the bottom of the ditch fierce collision, lifting should have two supporting points, not two or more of the root of the welding after hanging into the ditch, it is strictly prohibited to hang through the heart.

3) For general soil, a layer of 100mm thick medium sand foundation shall be laid on the undisturbed foundation below the pipe bottom or on the backfilled rammed foundation; Can be used when the foundation soil is poorer, cushion layer is not less than 200 mm of gravel base layer, can also be divided into two layers laid, the lower of gravel, with 32 mm diameter is 5-100-150 mm thick, upper spread medium sand, thickness of not less than 50 mm.

For soft soil foundation, when the foundation bearing capacity is less than the design requirements or due to reasons such as construction of precipitation, the foundation undisturbed soil is affected by disturbance and the foundation bearing capacity, must first to reinforcement of foundation, after reaches the foundation bearing capacity, and laid in the coarse sand base layer.

3. Clean up the sewage at the socket:

1) Before installation of Krah pipe socket team, dirt at the pipe end shall be cleaned to avoid affecting the welding effect.

2) The small diameter pipe adopts the tensioner and binding auxiliary socket, and ensures that the socket is in place.

3) The large diameter pipe adopts the socket assisted by the excavator, but the socket depth line should be marked and pushed forward slowly to avoid damage to the pipe.

4. Cladding pipe connection:

1) Choose the matching welding machine and power supply according to different pipe diameters.

2) Correct welding parameters according to pipe diameter and weather conditions.

3) The connection between the electrode holder and the resistance wire must be firm and reliable to avoid electric spark at the contact part.

4) Tighten the socket with the hoop along the direction of the center of the circle while welding to ensure the tight fit of socket.

5.Cooling

HDPE pipes do not dissipate heat. In order to prevent large amount of heat accumulated in the welding area from burning slowly under the influence of the duct draught, cold water can be poured after natural cooling for forced cooling.

6.Backfilling for construction of cladding pipe：

1) Silt, humus, topsoil and organic matter shall not be backfilled; Backfill should not contain bricks, stones, frozen earth blocks and other miscellaneous hard objects.

2) Sand must be backfilled and rammed layer by layer within 50cm of the pipe top, and the backfilling height of each layer is 15-20cm.

3) Manual backfilling must be carried out within 70cm of the pipe top. Direct earth pushing into the trench is strictly prohibited. Mechanical backfilling can be carried out over 70cm of the pipe top.

4) The joint is exposed during backfilling, which is convenient to check when the water is closed.

7. Closed water test of carat tube:

1) The test head is generally 2M.

2) If the water leakage of the pipeline meets Qs 0.0046Di, it is qualified.

Above is the installation and construction process of the Krah pipe, EAGLE Machinery Co., Ltd hopes to be helpful to everyone.