Germany-based Esser-Werke has designed ‘Big Mouth XL’ flanges for twin pipes, which can extend the life of these pipes by 50 per cent.

“Twin pipes, which are mainly used on truck-mounted concrete pumps, consist of an ultra wear-resistant hardened inner pipe and a pressure-resistant weldable outer pipe, both of which are produced separately. The inner pipe is then inserted into the outer pipe and hardened. The simultaneous hardening of the twin pipes results in unsurpassed resistance to wear,” explains a spokesperson for the company.
However, when abrasive media, such as concrete is being pumped, the inner layer is naturally exposed to wear, which may not occur uniformly throughout the entire length of the individual pipe and elbow.
Commenting on the unevenness of the wear, the spokesperson points out, “Numerous field tests and examinations on worn pipes have shown extreme wear in the inlet area, while at the centre of the pipes, almost 50 per cent of the initial wall thickness was still in good condition.”
In order to achieve a better wear life uniformity, the solution was to optimise the design of the inlet flanges. The ‘Big Mouth XL’ flange achieves just that, according to him. He explains: “The ‘Big Mouth XL’ consists of an improved twin cast inlet ring in conjunction with an inlet flange extension approximate 160 mm in length, which absorbs the initial wear at the inlet end. Comprehensive tests have shown a life improvement of approximately 50 per cent, on using the ‘Big Mouth XL’ flanges.”
These pipes with the new flanges can be retrofitted to most pumps from the various concrete pump manufacturers. Possible mounting problems can be analysed by Esser-Werke when a quotation is submitted. Generally, Esser-Werke prefers to supply the ‘Big Mouth XL’ flange with the newly-designed 3.0 and 1.5 mm pipes, according to the company. The inner diameter (ID) of the pipes is 125 mm. The wall thickness of the inner hardened pipe is 3.0 mm, while the wall thickness of the outer static pipe is 1.5 mm. The new style ‘Big Mouth XL’ flanges are also available for pipes with the ID of 117 mm and 112 mm for large-size boom pumps.