Company Details
Unisite Group Ltd.
Unisite Group Ltd.
dredging suction pipes,suction tube,suction connecting tube,pipe joint
From the side of the ship one or two suction pipes descend to the bottom of the seabed. On the end of the pipe a so-called trailing Drag Head is connected. This head is comparable to a large vacuum cleaner and is trailed along the seabed. In the head there are nozzles connected to a high pressure water installation that are capable of loosening the material on the seabed. Due to lower pressure in the pipe, the material will be sucked inward and discharged in the hopper.
The vessel should always have a positive speed over the ground. It is possible to regulate the density of the sucked substance. If the head is lowered, more material will be sucked but there is a greater possibility of damaging the installation because the material can get stuck inside the pipes. Once the mixture is loaded inside the hopper, the substance will sink and the water is discharged overboard, creating more room for extra substance. A trailing Suction Hopper Dredger is only capable to suck relatively loose substance because the steel teeth are not so big. Harder substances such as rock, or ironbased rock must be destroyed by a cutter.
Photo of our Suction Pipe:
The specifications of our suction pipe
A. General
High accuracy, fully welded, painted construction can be used for trailing suction hopper Dredger, suction pipe plays an important role. It is approved BV
Suction pipe system ensure full control of the drag head on the bottom, transport the dredge mixture to the hopper, then transmit the trailing force from the drag head to the ship and support pipes and cabling.
B. Construction and procedure
The construction is to be built according to the drawing with rules of good workmanship and to be built the longitudinal frame system.
The construction consist big suction pipes, Turning Gland, joint, jet line, Seamless Pipes, supports for cable and hoses, which are carefully manufactured and checked to ensure total length, straightness, symmetry within the specific tolerances.
C. Procedure
Welding seam preparation-Pre roll bending of plate tip-Rolling-Longitudinal welding (SAW),inside then outside-Crossing welding (SAW) between part tubes to form the whole pipe-US testing and repairing-Adjusting-Assemble other part
D. Materials
All fabricated steelwork used in the construction of the suction pipe will be to manufacturing standard of classification society BV, GL, LR, DNV, especially for neck flange.
All steel used to be blasted and shop primed both sides. Using DH36
All materials proposed will be selected to comply with the latest Health and Safety Rules.
Paint systems for hull protection will be of the highest quality (Hempel, Inter, Sigma, Jotun)
E. Welding
All welding will be performed in accordance with drawing and order and UniSite experience and all welding will be continuous and full penetration.
Welding seam preparation, welding method, welding material and consequent preheating temperature acc. to UniSite standards and approved by clients.
F. Workmanship
The workmanship have good marine practice. Care are taken to ensure fair lines, smooth surfaces and neat welding.
G. Main particulars
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| MAIN PARTICULARS |
| Tolerance | High accuracy(ISO2768, ISO5817, ISO13920) |
| Material | Q345D, DH36 other materials |
| Dimension(L*B*H) | As per drawing, as large as we can |
| OD | 1000mm-2000mm |
| Weight | 15Ton~70Ton |
| Coating | Sa2.5 blasted and two or three layers painted with highest quality |
| Marking | as per clients' requirements |
| Inspection | material, construction, dimension, welding seam, non defective test, paint inspection |
| Experience | We made a whole suction system with length 49.3m for world top dredging company. |
| Others | Recyclable, in line with environmental requirements and standards, and reliable |
