University of Manchester

Investigating the Correlation between Defects in the Pipe Coatings and Processing Parameters

Greeshma Nuthalapati
Project Completed

Scientific Case

I, as a materials research scholar, am working on a research project – “Investigating the correlation between defects in the pipe coatings and processing parameters”. The insulation coating on the pipe bears significant importance due to its use in various applications for transporting materials in different phases (Gas and liquid). However, the life, insulating efficiency and cost is of paramount importance for processing such coatings. I am studying the interfacial bonding between layers of these coatings at micrometer to few millimetres resolution.
Aims and Objectives:
As there are various polymers and a number of layers, it is important to inspect such joints for its integrity and relate it to processing parameters. Since coating thickness is high (15 mm coating thickness on pipe of 250 mm diameter and 130 mm thickness on a pipe of 110 mm diameter ), it is imperative to set a method to detect defects in coating non-destructively. Because of high thickness, X-ray imaging is fit for the purpose. Hence, the aim is to image coating using variety of parametric combinations to optimize the results and find out the feasibility of using such method. All the images will be used to find defects and heterogeneity in the joints located between the sections of insulation.
i. To find smallest defect of 1mm (approx.) and in upwards of 1mm.
ii. Use depth resolved imaging to image each layer independently
iii. Create a 3-dimensional imaging of the coating.
iv. Optimization of spatial resolution versus depth resolution and speed (depth resolved imaging)
v. Vary contrast and incident wave energy to obtain better images
To improve contrast and ability to detect smaller defects, some samples will have an added contrast agent
Preferable Date:
23-04-2012 to 27-04-2012. However, we are happy to match available dates for equipments.
We would like to book 2 days on the scanner: Metris X-tek Custom 320kV bay so that we will get a CT image of the pipes. And for the thinly coated samples, 1 day on the Rapiscan RTT20 is required for the study. The samples with thin layers can be accommodated in Rapiscan.
also steel

Experiment Design

defects (void), interface, bonding defects, metal to polymer bonding

smallest feature size - maximum 1mm void,
resolution - 200 microns
Scanners and Rigs
Nikon Custom 320kV Bay
Not Required

Sample & Safety

no hazardous polymer coating
heavy weights (around 50 Kgs)

Scan Records

Nikon Custom 320kV Bay
489 uA
Scan dates: 31/05/2012 to 01/02/2012 for 4 scans.

Project Report