Off Shore EF Coupling system for d1600 mm

Off Shore EF Coupling system for d1600 mm

TEGA has developed a special EF coupling system for water transmission line from Turkey to Cyprus. The technical files of the project has submitted on the attachment. This is unique and patented product.

Off Shore EF Coupling system for d1600 mm

The pipeline will follow the sea floor near the shore at the Cyprus and Turkey ends. When the water depths exceed 280m the pipeline will be suspended using a floating pipe arrangement. In this arrangement, the HDPE pipe is suspended at a water depth pf approximately 250 m in spans of approximately 500m length each. Adjacent spans are mechanically joined by a connector called Y-piece, and the joint is connected to the seabed by means of a tether and anchor system/ A total of 132 regular, and 2 half Y-piece will be used throughout the route.

Y-piece design alternative

By improving this design, TEGA has reached a good offshore engineering solution for connecting PE pipes. The advantages of this design are listed below:

  • The gaskets are not used in this design. Because of it, no need to take the Y-pieces to the sea surface and change the gaskets or find a way to inject liquid gasket in to the metal connection piece.
  • EF welding is made by using electronically controlled automatic welding machine. And this machine has automatic data record system for each welding to control safety of welding.
  • EF couplers for 1600 mm are trustable and used method because TEGA has field experience for some international projects with this diameter.

To prevent vertical shear forces onn the pipe system; Tega has desiged to use 12 EF flex restraints on each Y-pieces (3+3;3+3). Tega has industrial experience for this type of production. This flex restraint is a used and proven methot in industrial application. Use of EF flex restraints on this design will decrease vertical, critical and dangerous forces on pipe system.

Tega designed this piece by using electrofusion welding techniques. Electrofusion (EF) welding technique is the most preciousi most efficient and safest connection method for PE piping works. Tega has 20 years experience in this field up to 1600 mm and Tega also has the world record to be the onlyn company who can produce this biggest diameter on the world.


Component Name Meterial Type Maximum Equivalent Stress (MPa) Safety Factor
Main Body St52 120 3
Upper-Interface St52 85 4,1
HDPE Polyethylene 7,5 Lower than 8 MPa
EF Flex Restrain Tega Y Polyethylene 5 5
Loose Flange Tega Y St52 90 4
Ef Coupler Tega Y Polyethylene 4 6,1


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