Hose lines are often referred to as a weak machine component. Wrongly so. Sometimes they do more than tubing lines, and their maneuverability is what makes operation truly flexible. And in certain areas, hose lines are indispensable. They may, however, become a hygienic and safety risk under some circumstances. To prevent this, certain key points are to be taken into consideration when dealing with hose lines.
Food safety and hygiene play a key role in the food industry – in the production as well as regarding the machines, systems and hose lines, which are indispensable as a flexible transport link for conducting the most diverse media. But one hose is not just like the next, so care is necessary in choosing the correct one. Many of the numerous types of rubber, fillers, plasticizers and other anti-aging agents marketed are not suitable for foodstuffs. Quality control reports or certificates of conformity issued by renowned institutes guarantee that the material conforms to the globally recognized directives of the US Food and Drug Administration (FDA) and that it does not transfer odor or taste to the media being processed – and thus the food. The Lactopal food hose from ContiTech complies with the guidelines of the US FDA. The white non-porous inner lining of the hose is absolutely odorless and has no effect on the taste of the milk.
Focus: Critical points when it comes to hygiene
Besides selecting the right hose material, the fitting, cleaning and disinfection of the hose lines, regular inspections and protection against mechanical damage are some of the key points to be observed when dealing with hose lines to ensure that they do not become a hygienic risk. With this in mind, the hose lines should also be integrated as part of an internal HACCP concept. The goal of the internationally recognized hazard analysis is to ensure food safety and product quality by checking and controlling critical control points.
Control point I: The fittings
Quick-connect hose clamps are still a popular and widely used fitting type despite the fact that they present a particularly high hygienic risk. This is due to the fact that the hose nipple can become separated from a hose so fitted if the line becomes severely bent at the hose end, forming a so-called dead space in which the medium can collect. In turn, this results in dirt cavities, which are difficult to clean even after they have been located. With pressed fittings, no dead unhygienic space is created, especially if the outer sleeve of the fittings is longer than that of the inner supports, as is the case with the PAGUFIX 4000 and Blaudieck swaged fitting systems from ContiTech.
Control point II: Cleaning and disinfection
It must be possible to keep objects and equipment such as hose lines that come in contact with foodstuffs clean and maintained, and, if necessary, to disinfect them. Users should therefore ask hose suppliers for documents specifying hose resistance properties with regards to cleaning agents and disinfectants. Remarks such as “for brief periods” or lists of temperature possibilities or exposure times are however not of much help to users. In order to prevent the hose material from suffering damage, it is necessary that documents specifying cleaning agent and disinfectant resistance include basic cleaning agents like water, steam, and sodium hydroxide solutions, plus various combination preparations, with information on the maximum duration of exposure, working temperature and concentration. Owing to the diversity and ongoing changes in the composition of the various agents, it is impossible to provide exhaustive documents containing all cleaning substances. However, ContiTech can supply appropriate information on request. And where necessary, the manufacturer of the cleaning agent can be consulted to determine the parameters required. This increases production reliability accordingly. It is also important in this context to inform users that the concentration of many disinfection agents should only be as high as that recommended by the manufacturer when they are being used for extended disinfection over the weekend.
Food hoses with thermoplastic inner linings like Blaudieck LGDU satisfy the steadily increased demands of the food industry with regards to highly concentrated and aggressive cleaning agents and disinfectants as well as temperatures until 950 Celsius. Furthermore, the thermoplastic inner linings prove to be particularly resistant to extended disinfection over the weekend.
Control point III: Regular inspection
Hose lines made of rubber and plastic-rubber composites are subject to natural aging. This can be accelerated by strong mechanical stressing such as bending or motor-driven reeling etc. as well as thermal factors like water temperatures exceeding +85°Celsius, steam temperatures over +130°Celsius or exposure to steam exceeding the maximum permissible time. Users are therefore encouraged to inspect the condition of the hose lines on a regular basis. The safest way to monitor hose lines is with an identification and documentation system in which the lines are clearly labeled with identification numbers, which are in turn documented. These preventative measures can indicate damage early before the line fails and help to extend the service life of the hose line considerably. Specialized companies that assemble fittings and hoses into functioning hose lines offer a wide range of services in this regard. As a rule, these companies have staff trained in this area as well as mobile inspection equipment. This usually includes an endoscope, with which damaged areas can be documented using digital, electronic recording technology, thus providing valuable information that aids the hose line operator's decision making.
Control point IV: Protection from mechanical damage
But not only with respect to regular checks, it is good to keep in mind that: “A stitch in time saves nine.” Practical hose recoilers and hose line holding brackets as well as protective rubber rings on the fittings help prevent damage to the hose lines.
Economy and profitability
Differences in quality and thus the durability of materials for hoses used in the food industry usually cannot be seen at first glance. If hose lines are inspected regularly according to a set schedule and documented accordingly, as a rule it quickly becomes obvious that material which may have seemed to be expensive at the beginning turned out to be a better deal thanks to its service life, reliability and safety. Therefore when selecting a hose and fitting system, one should take into account not only the purchase price but also the possible follow-up costs resulting from a lack of hygiene, loss of production as well as insufficient industrial safety, in accordance with the total cost of ownership process.