Material qualification and testing at NKT Flexibles
The laboratory is equipped with high capacity ventilation as well as continuous monitoring of the working environment and alarms for H2S leakages. For preparation of test gasses, the laboratory contains advanced gas mixing equipments, which can generate test gasses with any composition of up to three different gasses.
Today the NKT Flexibles material testing laboratories have an almost complete envelope of test facilities and methods for qualification of materials as required in API17B and API17J. A more detailed description of the capabilities of the Sour Service Laboratory and The Polymer Laboratory is given in the “facts” boxes.
Sour Service laboratory
The laboratory is used for testing in environments containing hydrogen sulphide (H2S). The laboratory is equipped with high capacity ventilation as well as continuous monitoring of the working environment and alarms for H2S leakages. For preparation of test gasses, the laboratory contains advanced gas mixing equipments, which can generate test gasses with any composition of up to three different gasses. The permanent test setups includes:
Test for Sulphide Stress Cracking (SSC)
The SSC tests are conducted in accordance with NACE TM0177 method A. The test facility includes 20 test stands with a capacity of 5 tons and 10 test stands with a capacity of 20 tons. All parameters such as load, pH, gas composition etc. are monitored continuously during the test and data-logged for documentation.
Test for Hydrogen Induced Cracking (HIC)
The laboratory can conduct a high number of simultaneous HIC test in accordance with NACE TM0284.
Test for corrosion fatigue
Three test stands with a capacity of up to 8 specimens each test fatigue on wires in a corrosive environment. The test is conducted as deflection controlled four point bending test, typically at 0,5
Hz.
Test of Corrosion Resistant Alloys (CRA)
Compatibility tests on CRAs are performed in a 20 litre autoclave, capable of 40 bars pressure at 180°C. Tests are typically performed as 720 hours exposure to a specified environment, followed by inspection for signs of corrosion and determination of weight loss as outlined in EFC publication no. 17.
H2S Permeation
Measuring permeation of H2S in polymer liners is carried out in a cell using the varying pressure method. The cell can withstand pressures up to 60 bars at 130°C.
Polymer laboratory
In order to test polymers and developing the processing of polymers, the polymer laboratory is equipped with a large number of standard analytical instruments as well as small-scale laboratory extruders, and compounders.
For characterizing polymers use of thermal analytical techniques like Differential Scanning Calorimitry (DSC), Thermal Mechanical Analysis (TMA) and Thermo Gravimetric Analysis (TGA) are used in combination with techniques like Infrared Spectroscopy (FTIR), Gas Chromatography (GC) and High Pressure Liquid Chromatography (HPLC). To analyse flow characteristics, the laboratory is equipped with a Capillary Reometer and an Instron tensile test stand, which in addition to tensile strength and elongation can measure creep and stress relaxation.
Chemical compatibility tests and ageing experiments are performed in autoclaves, ranging from a number of 20 litres autoclaves capable of a pressure of 5 bars at 150°C, to some 1 and 2 litre high pressure autoclaves capable of a pressure of 500 bars at 150°C. A small autoclave is dedicated testing resistance to blistering. The autoclave can operate at 700 bars and 150°C, and expose samples to explosive decompression at rates up to several hundreds of bar pr minute. Gas mixing equipment with high pressure booster pumps facility the autoclaves with gas mixtures at high pressure.
Gas permeability is measured by extruded liners. The laboratory is equipped with three cells for measuring permeability at pressure up to 60 bars at 130°C. The cells are connected to an automatically operated Gas Chromatograph allowing measuring of interaction of permeability from multicomponent gasses. In addition, a high pressure setup enables measuring of gas permeation at pressure up to 700 bars and a mid-scale test setup simulates the pipe geometry and allows us to see effects such as shielding from armouring layers.