Search results

1 – 10 of 527
Content available
Article
Publication date: 1 April 2003

Abstract

Details

Aircraft Engineering and Aerospace Technology, vol. 75 no. 2
Type: Research Article
ISSN: 0002-2667

Keywords

Content available
Article
Publication date: 1 April 1998

Abstract

Details

Aircraft Engineering and Aerospace Technology, vol. 70 no. 2
Type: Research Article
ISSN: 0002-2667

To view the access options for this content please click here
Article
Publication date: 1 February 1991

B.N. Ellis

This paper outlines the composition of water soluble fluxes for the electronics industry and their methods of use when wave soldering and reflowing tinned coatings and…

Abstract

This paper outlines the composition of water soluble fluxes for the electronics industry and their methods of use when wave soldering and reflowing tinned coatings and solder pastes. Process optimisation is facilitated by the Taguchi method. Three types of cleaning machinery are evoked, with varying results. It is shown that the energy/time relationship is important to ensure adequate cleaning quality. A number of fallacious arguments are debunked. Methods of water purification and the problems of effluent treatment for all sizes of installation are addressed. Doubt is expressed as to the viability of closed‐circuit water recycling except for the largest installations or where exceptional conditions prevail. It is shown that water soluble fluxes and their subsequent aqueous removal are unlikely to make any significant contribution to the Greenhouse Effect. The overall cost of their use is substantially similar to that of rosin fluxes with CFC‐113 azeotropes at 1986 prices. Cleanliness control under production and laboratory conditions is discussed with reference to both ionic contamination testing, including its use for SMDs, and SIR analysis, especially at low voltages, including non‐destructive production SIR testing. Reliability of the assembled circuits is shown to be at least as good as that with more traditional soldering and cleaning methods, frequently better, and this is the case even for military and aerospace applications. The paper concludes that, now that quality water soluble solder pastes are available, this method is most likely to become the workhorse for the majority of electronics applications.

Details

Soldering & Surface Mount Technology, vol. 3 no. 2
Type: Research Article
ISSN: 0954-0911

To view the access options for this content please click here
Article
Publication date: 1 June 1975

G. Clifton

Non‐destructive testing (NDT) makes use of the controlled application of physical phenomena to materials so that interpretation of signals derived from the materials…

Abstract

Non‐destructive testing (NDT) makes use of the controlled application of physical phenomena to materials so that interpretation of signals derived from the materials indicates their fitness, or otherwise, to perform a design function. The purpose of NDT is to ensure that mainly load carrying components and structures are free from defects. Established non‐destructive testing has become of primary importance in aircraft maintenance and manufacture both as a positive indication for safety and as a method of saving costs. This article written for aircraft engineers is a broad review of the development of NDT in their industry and a brief indication of the status of its various components today.

Details

Aircraft Engineering and Aerospace Technology, vol. 47 no. 6
Type: Research Article
ISSN: 0002-2667

To view the access options for this content please click here
Article
Publication date: 13 March 2007

Love P. Kalra and Jason Gu

The aim of this research is to design a wall climbing robot (WCR) for the non‐destructive inspection (NDT) of the above‐ground storage tanks (ASTs) autonomously making the…

Abstract

Purpose

The aim of this research is to design a wall climbing robot (WCR) for the non‐destructive inspection (NDT) of the above‐ground storage tanks (ASTs) autonomously making the industrial inspection and maintenance tasks safer.

Design/methodology/approach

A WCR is designed that can be equipped with any NDT sensor. It uses permanent magnets as an adhesion mechanism to crawl over the steel tank walls. A surface coverage algorithm is proposed for the WCR to scan the AST wall surfaces autonomously with the NDT sensors to perform the necessary inspection tasks.

Findings

The proposed surface coverage algorithm performs the complete coverage of the AST walls under different obstacle configurations. It has been tested and demonstrated in simulations.

Originality/value

A surface coverage algorithm is proposed for the WCR to perform the non‐destructive inspection of the ASTs autonomously. It can also be used in applications like cleaning glass building and painting ship hulls, etc.

Details

Industrial Robot: An International Journal, vol. 34 no. 2
Type: Research Article
ISSN: 0143-991X

Keywords

To view the access options for this content please click here
Article
Publication date: 1 April 2005

A. Correia da Cruz and M. Silva Ribeiro

To present an entirely new technology to be used in the in‐service inspection of storage tanks for hazardous products in several different industries.

Abstract

Purpose

To present an entirely new technology to be used in the in‐service inspection of storage tanks for hazardous products in several different industries.

Design/methodology/approach

Current interior storage oil tank plate inspection is a very expensive and time‐consuming task. The related tasks involve high cost, several hazards to environment and the operators involved in the cleaning jobs. Several research areas were investigated during the development of this tool, fundamentally robotics and non‐destructive test tools. Initial trials in laboratory were complemented with a field test program in near‐real conditions.

Findings

A new design of tool for in‐service inspection of such equipments proved to be feasible to be constructed and operated and in accordance with current safety regulations.

Research limitations/implications

New robotics application in non‐destructive testing methodologies for application in in‐service storage equipments. The internal conditions possible to find in the interior of a storage tank, like fixtures, properties of the stored products (inflammable and aggressive), sludge and sand on the bottom, no ambient light, etc., are significant challenges to the development of such a tool.

Practical implications

Developed a robotized tool for inspection of the floor and walls of in‐service tanks, in order to allow an evaluation of the condition of the plates of these tanks, avoiding the long period, hazards and high costs necessary for creating the conditions for reality out of service inspection.

Originality/value

The novelty of the RobTank Inspec project could be evaluated from the two or three existing competitors in the world, and the results of the surveys undertaken.

Details

Industrial Robot: An International Journal, vol. 32 no. 2
Type: Research Article
ISSN: 0143-991X

Keywords

To view the access options for this content please click here
Article
Publication date: 1 August 1996

B.N. Ellis

Surface insulation resistance (SIR) testing is mainly used as a qualification procedure to determine the‘best’ combination of materials and processes for a given…

Abstract

Surface insulation resistance (SIR) testing is mainly used as a qualification procedure to determine the ‘best’ combination of materials and processes for a given application. The usual tests are destructive and last generally from ten to 56 days, 28 days being very common. It is clear that such tests are unsuitable for production quality control. With cleaned boards, ionic contamination testing is current and is specified in many standards. Even so, the presence of non‐ionic hygroscopic contaminants, such as residues from many fluxes and solder pastes, remains undetected. Their presence may cause functional failures, especially if there is some ionic contamination, even within acceptable limits, as well. When using ‘no‐clean’ fluxes and pastes, ionic contamination testing is sometimes used to determine whether a process is constant, although it may be extremely difficult or even impossible to interpret the results into a function of reliability. SIR testing is the only easy way of forecasting a loss of reliability. A method is described of non‐destructive SIR testing in a few hours and correlating the results to reliability as determined by long‐term qualification testing. This method is valid for PCB assemblies which have or have not been cleaned.

Details

Circuit World, vol. 22 no. 2
Type: Research Article
ISSN: 0305-6120

Keywords

To view the access options for this content please click here
Article
Publication date: 24 August 2010

Robert Bogue

The paper aims to provide a review of the uses of robots in non‐destructive testing (NDT).

Abstract

Purpose

The paper aims to provide a review of the uses of robots in non‐destructive testing (NDT).

Design/methodology/approach

Following a brief introduction, this paper considers the uses of robotic NDT, with an emphasis on applications in certain key industries. While some development activities are considered, the emphasis is on existing systems rather than research and reference is made to a selection of commercial products.

Findings

It is shown that robotic NDT finds limited uses in most of the industries using conventional NDT methodologies. These include oil and gas, offshore and shipping, petrochemicals, aerospace and power generation. In some instances, financial benefits arise from their use while in other cases the use reflects access difficulties or the hazards associated with testing.

Research limitations/implications

Applications in the nuclear power industry is not considered but will be covered in a subsequent article. Remotely operated vehicles, which are not considered to be true robots, are also excluded.

Originality/value

This paper provides details of NDT robots and their uses in a selection of key industries.

Details

Industrial Robot: An International Journal, vol. 37 no. 5
Type: Research Article
ISSN: 0143-991X

Keywords

To view the access options for this content please click here
Article
Publication date: 31 May 2011

Giovanna Concu, Barbara De Nicolo and Luisa Pani

This paper aims to report a case study regarding the combined use of several non‐destructive techniques (NDTs) as a tool in the management of diagnosis and refurbishment…

Abstract

Purpose

This paper aims to report a case study regarding the combined use of several non‐destructive techniques (NDTs) as a tool in the management of diagnosis and refurbishment of a damaged reinforced concrete building.

Design/methodology/approach

Four types of NDTs have been selected and carried out on the pillars of the building: visual inspection, electromagnetic rebar location, sonic test and rebound hammer test. The campaign has been planned and run in order to get the highest amount of reliable data about materials degradation and structural safety with limited costs and limited interference with the functionality of the building.

Findings

The diagnostic campaign highlighted the usefulness of the selected techniques in the diagnosis of the type and the amount of degradation, thus permitting a plan of refurbishments to be defined, and to get a realistic estimation of restoration costs.

Practical implications

NDTs' ability to specifically identify a type of damage may be viewed as a reliable tool in assessing and managing the structural life‐cycle cost.

Originality/value

The presented case study highlighted that NDTs are very likely to locate and quantify the damage of materials and buildings, so that they can be considered as one of the most important parts of health monitoring of civil structures and infrastructures.

Details

Structural Survey, vol. 29 no. 2
Type: Research Article
ISSN: 0263-080X

Keywords

To view the access options for this content please click here
Article
Publication date: 7 March 2016

Frazer Howard Smith

During offshore pipe-lay, pipe lengths with anticorrosion coating are welded together, and, to facilitate the welding process, the ends of the pipe remain uncoated. A wide…

Abstract

Purpose

During offshore pipe-lay, pipe lengths with anticorrosion coating are welded together, and, to facilitate the welding process, the ends of the pipe remain uncoated. A wide range of field joint coating (FJC) types is available for coating this bare section, functioning in conjunction with the pipeline cathodic protection system to provide an anti-corrosion system or package. This paper aims to relate to two-layer type heat shrink sleeves (2LHSS), which commonly are used for FJC of concrete-weighted offshore pipelines where the sleeve typically is over-coated with a solid or foam type polyurethane “infill”. Similar sleeves also are used sometimes in exposed conditions on lines without concrete over-coating. The maximum allowable soluble salt contamination prior to application of high-performance coating systems can vary, depending upon the coating type, but typically has been set at 20 mg/m2 (de la Fuente et al., 2006). The first layer of three-layer heat shrink sleeve (3LHSS) systems for pipeline FJC, liquid epoxy, falls into this category (ISO_21809-3:2008, 2008). In contrast, the 2LHSS system does not use a liquid epoxy first layer but relies instead on the bonding of a “mastic” layer directly to the pipe metal surface. The maximum acceptable concentration of salt contamination on prepared metal surfaces prior to the application of 2LHSS has been a subject of debate and was the focus of this study. International standards for FJC do not provide a maximum salt level. However, some companies have continued to specify low thresholds for the maximum allowable salt level for 2LHSS, which can result in expensive delays in production during offshore pipe-lay. In this study, salt contamination levels of up to 120 mg/m2 were found to have no effect on peeling performance after accelerated aging by hot water immersion. Furthermore, preparation for welding and the use of potable water during ultrasonic testing procedures prior to FJC, typically reduces the salt contamination level to below 50 mg/m2 providing a strong case for the deletion of salt contamination testing for 2LHSS.

Design/methodology/approach

The potential risk of failure of the coating due to poor surface cleanliness/contamination was assessed by testing the adhesion between the coating and the steel substrate to which the coating is adhering, following a period of hot water immersion. Compliance with ISO 21809-3 “Annex I” requires 28 days’ immersion at maximum operating temperature. For this study, to create a severe situation, the test rings were subjected to accelerated aging by water immersion at the HSS upper specified temperature of 65°C for more than twice the specified period (ISO_21809-3:2008, 2008). Two HSS were tested; one was widely used in applications where exposure to moderate mechanical stress is required, having a high shear strength type mastic “hybrid” adhesive containing a significant proportion of amorphous polypropylene blended with tackifiers and ethylene vinyl acetate (EVA), Andrenacci et al. (2009) referred to as “Type A”. The second, referred to as “Type B”, is widely used in applications where it is covered by a layer of “infill”, typically consisting of polyurethane foam or solid polyurethane elastomer, i.e. typical design methodology for concrete coated pipelines. “Type B” HSS had a more moderate strength traditional type mastic than “Type A” containing a significant percentage of butyl rubber with asphalt, activation agents and tackifying resins. To determine how to apply the salt contamination without causing flash rust, a mini-study was completed on the steel substrate. After numerous trials, it was found impossible to not to form visible rust on the pipe surface. The extent of rusting was minimised by heating the pipe immediately after the application of the salt solution.

Findings

High levels of sea salt on power tool prepared pipe surfaces were investigated by peel testing of 2LHSS after hot water immersion and compared against peel tests undertaken prior to hot water immersion. The test conditions were considered severe: salt contamination levels of up to 120 mg/m2 applied on power tool cleaned pipe surfaces that had been aged for one year without prior grit blasting. The accelerated ageing procedure had twice the specified (ISO_21809-3:2008, 2008) water immersion duration, and the test samples had exposed edges providing the possibility for moisture to creep under the coating. The test results showed that there were no noticeable deleterious effects on the performance of the two most commonly used FJCs, 2LHSS. Therefore, it was concluded that, as the level of salt contamination on prepared pipe surfaces after wet non-destructive testing typically is much lower than the levels tested in this study, pipe surfaces prepared for the application of 2LHSS type do not require specific additional measures to further reduce salt contamination, provided that care is taken to ensure that these conditions are maintained consistently during pipe laying operations.

Practical implications

The frequency of salt contamination testing of power tool cleaned surfaces prior to mastic type heat shrink sleeves can be minimised, and perhaps omitted entirely, provided the above criteria are satisfied.

Originality/value

A literature review revealed there was little published information on the testing of 2LHSS and nothing related to hot water immersion testing. Hence, the results of this investigation have provided useful industrial data regarding the effect of hot water ageing and the influence of surface salt contamination on field joint corrosion prevention capabilities.

Details

Anti-Corrosion Methods and Materials, vol. 63 no. 2
Type: Research Article
ISSN: 0003-5599

Keywords

1 – 10 of 527