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What is flexible straight joint steel pipe?
Dec 14, 2018

What is flexible straight joint steel pipe?

Flexible straight joint steel pipe has four layers. The inner layer is extruded thermoplastic pipe, which plays a sealing role in liquid transfer. The middle two layers are lined with carbon-filled polyethylene tubes that are resistant to long-term ultraviolet radiation and can eliminate external static electricity. The outermost layer is a thick outer protective cover formed by extrusion to protect the bottom layer of the pipe from external influences.

Because there is no wear-resistant pipe corrosion caused by forced closure or even shutdown of the things often happen, flexible steel pipe repair technology can not only save costs, but also reduce the damage to the environment.

The design of offshore flexible steel tubes is based on API17J, 17K and RP17B. The design standards for onshore flexible steel tubes deviate slightly from the requirements of API standards. API17J classification method and materials are used, and the pressure, tension and failure limits are all within the specified range. The test was conducted in accordance with the requirements of APIRP17B. Terminal fittings shall be designed to maintain structural integrity, ensure internal and external extrusion molding layer seals, and ensure that tension and pressure loads are transferred to the pipe structure. Samples of terminal fittings were tested by blasting and axial tension.

A 2km long 6in pipeline in Canada has been shut down because of corrosion problems. The pipeline runs through five or six landowners, and it was particularly difficult to apply for a new one, so it was decided to repair it. Wellstream's solution is to attach a flexible piece of steel to an old pipe so that it does not have to apply for a new pipe, saving money and reducing environmental damage. The pipeline is designed to deliver liquid carbon dioxide to the injection wellhead to increase oil production. Where to the mouth of the well, there are two 90 ° bend and a road through the area. The pipe should pass through pigging, removing and other obstacles before entering the operation.


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