TPI January 2014

products & developments

Weld seam detection on precision steel tubes

detection. In the process of welding ferromagnetic steel, martensitic crystals are formed within the range of the heat effect zone. Since martensitic crystals hardly occur in the unwelded structure, the welding seam is detected by the crystal structure modification. The SND40 weld seam detector supports these alternative techniques and offers high process reliability in practical usage. Roland Electronic claims that tubes with scraped weld seam and calibrated diameter will reach in the first detection run ratios of 99.9 per cent, and that the error rates in detection with an SND40 system are between 0 and 100 ppm. Roland Electronic GmbH – Germany info@roland-electronic.com www.roland-electronic.com

be visible. This problem arises when an application requires a treatment of the tube after welding, for example in the production of precision steel tubes. The cold drawing of the tubes changes the original surface and impedes the use of colour. If the tube is additionally annealed, the welding seam may become invisible in its external appearance. Roland Electronic offers alternative techniques, well known from the non- destructive testing of materials with eddy current, magnetic induction and the magnetic leakage flux method. These techniques have the advantage of dry functioning, without significant radiation exposure.

The position of a weld seam has a crucial influence on the quality of the final product when bending or hydraulic forming a tube. An unfavourable seam position causes deviations in geometry, has influence on the firmness and in the life span of the produced component or precipitates by cracking during the manufacturing process. In order to prevent such disadvantages, different solutions for the localisation of the weld seam were established. Common optical procedures, such as colour marking of the longitudinal welds, in order to detect their position are widespread. Camera-based systems that detect the visible welding seam are also in use.

Crystalline modifications of the structure within the weld seam can be used for

However, colour marking is not always possible, or the welding seam may not

Quick-fit isolation valve receives WRAS approval

It can also be used as an emergency shut-off for leaking pipes.

NLB Engineering’s Aladdin EasyFit Isolator, a quick-fit plumbing isolation valve for 15mm pressurised pipe, has received approval from WRAS for use as a stop valve with a maximum working pressure of 16 bar. Company director John Heffernan commented, “A major UK water company requested we seek WRAS stop-cock approval for the Aladdin EasyFit Isolator. They already use them every week to fit in-house water meters, and they will now be used for many other routine jobs where the Aladdin EasyFit Isolator will become the standard replacement stopcock on the mains supply.” The Aladdin EasyFit Isolator installs into pressurised hot or cold pipe-work when the mains stopcock is seized or inaccessible. It avoids draining down

Aluminium tube in China

A video is available on the product’s website (www.easyfitisolator.co.uk), showing how quick and straightforward the valve is to fit.

NLB Engineering Ltd – UK sales@nlbengineering.co.uk www.nlbengineering.co.uk

Aluminium precision tube made in China Cold drawn seamlesss tube Cold drawn coil tube For Seawater desalination device Power generation heat exchanger Industrial refrigerant system

NLB Engineering’s Aladdin EasyFit Isolator valve

WUXI HATAL ALUMINIUM CO., LTD No. 72, Zhouxin (E) Road, Binhu District, Wuxi, Jiangsu Province, 214121, China

Tel: +86 510 85069506 Fax: +86 510 85061423 E-mail: sales@hatal.com.cn

and re-filling of heating systems, and can isolate mains ware feeds in multi-occupancy buildings.

www.hatal.com.cn

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January 2014 Tube Products International