ACO B u i l d i n g D r a i n a g e Gully White Paper
White Paper ACO Stainless Steel Gully Systems - for specifiers, installers and contractors
Enhanced gullies for hygiene-critical environments
protected by a tough 2 – 5¾m thick chromium-rich oxide film (CrO) that is naturally corrosion resistant and its resilience is enhanced by spontaneous self-healing properties where oxygen is present. Therefore, in hygiene-critical environments, where resistance to corrosion is a necessity, stainless steel is by far the strongest option.
The increasingly demanding legislation imposed on operators within hygiene-critical environments presents many challenges; one requirement that must be satisfied is that drainage can provide a high level of hygienic integrity. Drainage components must be fit for purpose and designed to minimise the risk of contamination. The new ACO Gully range has been specifically designed to satisfy high-end hygienic performance applications with minimal bacteria traps at no extra cost, in accordance with European design standards Regulation (EC) No 852/2004 relating to the hygiene of foodstuffs. ACOs innovative new gully design was achieved in consultation with key stakeholders who offered input regarding design detail and identification of appropriate standards, including the guidelines of the European
Hygienic and Engineering Design Group, of which ACO is now a member. The full ACO Gully range has also been independently tested to BS EN 1253 – Gullies for Buildings. Gullies must not only provide the highest possible level of hygiene, they must also maximise tight budgets by offering a long lifespan with minimal demands on maintenance. The challenge was therefore to design a new gully range that offered high levels of hygiene while remaining cost effective and this was addressed by looking at both product materials and component design.
The ACO Gully range is constructed from highly corrosion-resistant austenitic stainless steel, ideal for hygienecritical applications as its nonporous state enables easy cleaning and disinfecting. All Gully systems are manufactured in either austenitic stainless steel grades 304 or 316 and are fully pickle passivated for optimum corrosion resistance. Pickle passivation is a controlled corrosion process involving nitric and hydrofluoric acids; it removes weld tint and iron embedded impurities introduced in the fabrication process, restoring the chromium-rich oxide layer that naturally protects the material to leave a uniform matt finish.
Stainless Steel
In recent years, ACO has been highly successful in tackling the challenges presented by hygiene-critical environments and one key development has been the use of stainless steel. This material lends itself readily to hygienic environments; it is
ACO Building Drainage, ACO Business Centre, Caxton Road, Elms Farm Industrial Estate, Bedford, MK41 0LF. Tel: 01462 816666. Email: buildingdrainage@aco.co.uk. www.acobuildingdrainage.co.uk.
System Design
To provide high levels of hygiene within a cost-effective package, ACO design engineers introduced a number of features. Elimination of lapped joints, provision of rounded internal corners and edge in-fill all contribute to improved hygiene and durability. In addition, the bowl-shaped design of the gullies minimises siltation and all models include an integral foul air trap. The new ACO Gully range has also been expanded to include a wider range of gully tops and gratings to suit a broader range of applications. Location flange telescopic bodies have been added to adhesive bonding and mechanical clamping flange options to minimise costs to customers.
microbial communities develop within aqueous environments. Food is affected by pathogenic, or disease causing, bacteria, so the main issue in hygienecritical applications such as food manufacturing and preparation is Listeria, which can kill vulnerable humans including pregnant women, the elderly and children, who have reduced immune defences.
ACO gullies have minimal bacteria traps, specifically designed to satisfy high-end hygienic performance applications. The construction follows European design standards for hygiene and utilises advanced manufacturing techniques. Crucially, gully design is based on knowledge of how
The bacteria is most commonly detected on floors and in drains, can grow under refrigeration and, since it must be killed by cooking at 70ÂşC for at least two minutes, presents a big problem in the food business. Listeria will readily attach to a drainage surface but good product design can minimise the risk. Free-form pathogens (those floating in water) are easily killed
by sanitizers and biocides but resistance to biocides increases by 100 times when a biofilm develops. Since rough surfaces encourage the formation of biofilm, smooth surfaces have been the goal for designers of the current components. This is why the smooth surfaces achievable in the manufacture of stainless steel components such as gullies have been so successful in minimising the potential for bacteria traps. So, by carefully considering the materials and component design possibilities, ACO has refined its Gully range to satisfy the high level of reliability demanded by hygiene-critical environments and the fact that the full ACO Gully range is independently tested to BS EN 1253 – Gullies for Buildings reduces risks for specifier, contractor and client.
ACO Building Drainage, ACO Business Centre, Caxton Road, Elms Farm Industrial Estate, Bedford, MK41 0LF. Tel: 01462 816666. Email: buildingdrainage@aco.co.uk. www.acobuildingdrainage.co.uk.