Two clamp systems for heavy and super-heavy, externally corrugated spiral hoses recently extended the product range of Norres, a hose manufacturer based in Gelsenkirchen, Germany. The Connect pressfitting system 232 is predestined for the food, pharmaceutical and chemical industries, while the Connect safety clamp system 231 is an attractive alternative in plastics production, for example.
Finding a way to achieve a permanently tight connection between plastic spiral hoses with standard fittings has traditionally proved a difficult challenge. The classic fixing element is a worm drive clamp. Special sealing clamps are another possible technique for assuring air and liquid tightness. The drawback of this attachment method, however, is that protruding clamp bands tend to get in the way when the hose is installed on a machine and can even be a cause of injury. Moreover, under high pressure, there is a danger that the adapter could become displaced or the system gradually lose its tightness. To avoid these risks, connections with cast parts are still a popular choice for attaching plastic spiral hoses to industrial machines. They can be either tightly pre-fitted to the hose or screwed on as cast fittings. Unfortunately, though, these polyurethane fittings cannot be made electrically conductive and cast types cannot be reused.
The Norres Schlauchtechnik R&D department has now come up with a threaded sealing insert that is adapted to the outer hose contour and assembled between the hose and the shell or pressing sleeve. The connection formed when the shells are clamped or the sleeves pressed together is remarkably tight. In the case of the 232 pressfitting system, users additionally profit from connections without any clearance spaces. Both these systems are designed with a form-locking groove and a form-locking bar. The resulting high tensile strength ensures that the adapter is securely held in the spiral hose even under considerable pressure. Furthermore, the hose’s metallic insert is exposed and contacted with the adapter when the systems are assembled. Clamping the shells or pressing the sleeves together creates a secure connection capable of electrostatic discharge.
The Connect pressfitting system 232 is specially designed for use in the food, pharmaceutical and chemical industries. The system comprises a stainless steel pressing sleeve and a sealing insert made of special premium polyurethane. It is leak-proof and easy to clean with no clearance spaces. The compatible Airduc PUR 355 MHF and 356 MHF hose types, either with or without a stainless steel coil, meet the requirements laid down for food and pharmaceutical applications in EU Directive 2002/72/EC, including the latest amending Directive 2007/19/EC, for the complete hose. The pressed fittings can be supplied in two different stainless steel qualities (1.4301 and 1.4404) for these two target industries. The batch number, the article number and the manufacturer’s name are printed on the system to simplify maintenance. Connect 232 is also offered for the Pre-PUR hose qualities Airduc PUR 355 MHF and 356 MHF with a spring steel wire or a stainless steel coil. The hoses are characterised by very high mechanical strength and low abrasion. They frequently exhibit better chemical and hydrolytic stability, and they impress with their higher softening points, greater residual strength at high temperatures and higher compression strength. Better hot air ageing properties and better flexibility at low temperatures are further advantages. The flexible hoses are transparent, allowing the process to be observed at any time.
For high flow-rates
The Connect safety clamp system 231 has a special, threaded sealing insert that is adapted to the outer hose contour. The system is consequently explosion proof and the clamp shells are suitable for reuse. In addition to this, the shells are made of aluminium, which means they are quick and easy to fit. The system is vibration-resistant, odourless and tasteless, resistant to microbes and hydrolysis, and softener and halogen-free. It can be used in conjunction with the Airduc 355 and 356 profile hoses for pellet suction and transport on pellet conveying systems in the plastics industry as well as for loading and unloading silos and assorted other applications with a high throughput of media like powder or pellets. The polyurethane employed for the sealing insert is food-quality and complies with the regulations of the American Food and Drug Administration (FDA 21 CFR 177.2600 and 178.20) plus the equivalent European Directives (2002/72/EC and 2007/19/EC).
The clamp systems are offered with a diameter of 25 to 100 mm. The connections are compatible with the Airduc 355 and 356 profile hoses. In future, it will also be pos-sible to connect the high-temperature Airduc 355 and 356 HT types as well as the electrically conductive Aircuc 355 and 356 EL. Finally, popular connection solutions, such as milk tube, aseptic, TriClamp or Kamlok couplings and fixed or loose flanges, can be connected easily and securely.
Hall 6, Booth 352
cav 404
Norres‘ product range
Powtech 2008
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