Lined Pipe Joint Sleeve for Sealed Welding and Pigging
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Solution Overview
Problem
Existing methods for joining lined pipes are incompatible with improved liners that feature a metallic barrier layer, leading to concerns about permeation and gas accumulation, which can cause pipeline collapse, and they also have deficiencies in joining conventional lined pipes, making them unsuitable for hydrocarbon service.
Innovation Solution
A method involving a fit-up sleeve that forces liners against castellations in fittings, with optional sealing rings and insulation, to create a secure and airtight joint, allowing for the use of porous inner polymer pipes that prevent gas accumulation and permeation, while reducing the need for corrosion-resistant alloys.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If conventional joining methods (WeldLink connection) are used to join lined pipes, then the pipes can be connected, but the liner becomes unlined near the weld exposing it to corrosive species and requiring expensive CRA cladding
Solution Approach 1:
A fit-up sleeve is introduced as an intermediary component between two lined pipes. The sleeve receives both liners and provides a sealed environment for the girth weld, acting as a mediator that protects the liner from direct exposure to the welding process and corrosive species. The sleeve includes a sealed end that prevents corrosive agents from reaching the liner near the weld joint.
Solution Approach 2:
The joining system is segmented into distinct functional components: the fit-up sleeve (for welding and sealing), the liner (for corrosion protection), and the castellations (for mechanical interlocking). This segmentation allows each component to perform its specific function optimally without compromising the others.
2Ease of manufacture
If conventional joining methods are used, then pipes can be joined, but the step change in internal diameter makes the pipeline incompatible with pigging operations
Solution Approach 1:
The fit-up sleeve is designed with a specific internal diameter that matches the pipeline, creating a localized region with uniform diameter. The sleeve's internal geometry is optimized to maintain consistent flow characteristics and pigging compatibility throughout the joint area, eliminating step changes while providing the necessary welding and sealing functions.
3Ease of manufacture
If electrofusion fittings with heating coils are used to join lined pipes, then the liners can be joined, but the electrical leads contaminate the girth weld between adjacent pipe lengths
Solution Approach 1:
The fit-up sleeve serves as an intermediary that physically separates the electrofusion fitting and its electrical leads from the girth weld zone. The sleeve's structure allows the heating coils to be contained within or separated from the weld area, preventing lead contamination while still enabling the electrofusion joining process to occur.
4Quantity of substance
If polymer lined carbon steel pipelines are specified instead of CRA pipelines, then cost is reduced by up to 50%, but concerns arise about permeation through the polymer and gas accumulation causing collapse
Solution Approach 1:
The liner is constructed as a composite structure combining polymer material with metallic barrier layers. This composite design leverages the corrosion resistance and cost benefits of polymer while incorporating metal layers to prevent permeation and gas accumulation, thereby maintaining reliability.
Solution Approach 2:
The liner incorporates porous metallic barrier layers that allow for controlled permeability characteristics. These porous structures provide mechanical strength and barrier properties while managing gas flow and preventing accumulation that could lead to collapse.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The method effectively joins lined pipes with improved liners, preventing permeation and gas accumulation, and reduces the requirement for corrosion-resistant alloys, enhancing pipeline integrity and cost-effectiveness for hydrocarbon service.
Implementation Method 1
inserting a first end of a fit-up sleeve into the first fitting to force a first liner against the first fitting
Implementation Method 2
the inner polymer pipe is porous which permits free movement of gas between the internal bore of a lined pipe and the barrier layer
Implementation Method 3
a metallic barrier layer, which prevents permeation through the liner
Implementation Method 4
The fit-up sleeve may be provided with a sealing ring which creates a seal between the liner and the fitting
Implementation Method 5
The fit-up sleeve may be provided with insulation between the liner and the host pipe
Implementation Method 6
The internal surface of each fitting is provided with a series of annular grooves and castellations
Implementation Method 7
The fittings are then welded together by an annular girth weld
Data Source
AI summary
Methods and apparatus for making lined pipelines in which pipes are joined together by attaching fittings at their ends and joining the fittings together. Within the joint there is a fit-up sleeve which forces liners against respective fittings and provides corresponding seals. Other seals can be provided by inserting sealing rings which force different portions of the liners against different portions of the fittings. The fit-up sleeve and sealing rings may force the liners against castellations which prevent movement of the liners. The fit-up sleeve may cooperate with insertion rims on the fittings to provide very accurate spacing, or touching edges which can be desirable if automatic welding is employed. The seals provided by the fit-up sleeve also eliminate backdraughts and assist welding operations. Furthermore, the fit-up sleeve permits pigging through the pipe joint and therefore along the length of the resulting lined pipeline. It is foreseen that the need for CRA components and CRA welding can be largely if not wholly dispensed with.