6

BUTTINGPNEUMATIC CONVEYINGI N S I D E S U R F A C E

Pipes with RAUMATIC surface finish

“Sauerkraut“, produced by deformedgranulates, can be avoided byroughened inner pipe surfaces

Material and usedefine the depth ofroughness

The overall quality of the pipeline systemmay be increased by special types of in-ner surfaces. The quantity and the qualityof the granulated material as well as thekind and velocity of the transport requireindividual depths of roughness. In order toensure the purity and the integrity of thegoods to be transported, various types ofsurfaces have proved successful.

Tailor-made for each projectBUTTING delivers at affordable pricespipes and pipe elbows out of hot-rolledparent material without further surfacetreatment, having roughness values ofapprox. Ra 3.0 – 7.0 µm. We have per-manently in stock pipes in cold-rolledraw materials and certain dimensions,having roughness values betweenRa 0.5 – 1.6 µm.

Nobody really wants “Sau-erkraut”Plastic granulates very often have to betransported over long distances from theunloading station to the processing ma-chines, using pipelines in aluminium or

Microphotograph of a roughened in-ner surface

Microphotograph of a shot-peenedinner surface

Producible roughnesses

Roughness (Rmax.)

Inner diameter Inside surface stainless steel Aluminium

PIPES 54.0 mm (at least) shot peened 40 – 70 µm 50 – 200 µm

80.0 mm (at least) roughened 150 – 300 µm 200 – 450 µm

ELBOWS 54.0 – 317.9 mm shot peened 40 – 70 µm 50 – 200 µm

80.0 – 110.3 mm roughened 150 – 300 µm 200 – 450 µm

100.0 – 317.9 mm roughened 70 – 150 µm 120 – 220 µm

stainless steel. When these granulates getinto contact with the smooth pipe wall,the friction pressure and the increasedtemperatures may lead to a partial plas-tification of the granulates. As a result,there is first the formation of a film andthen, subsequently, of fibres in the pipesand in the pipe elbows. The consequencesmay be material losses, impurities andeven a complete clogging of the pipelines.The aim is therefore to avoid such a pro-duction of “Sauerkraut“ or angel‘s hair.This process may be avoided by a specificroughening of the surface.