S/S chains on steamy water test baths
Methods
S/S chains on steamy water test baths
Keywords Corrosion,Stainless steel, Tsubaki, Water
Tsubaki's WP chain has overcome the problems of failure, due to corrosion of carbon steel chains used in a steamy aerosol test bath application at Nichol Beauty Products (Plate1). The WP chain has also overcome the subsequent problems of insufficient load capacity and elongation experienced with stainless steel chains which were used to replace the original carbon steel types.
Based in Thetford,Norfolk, Nichol Beauty Products is the UK and Europe's largest independently owned manufacturer of aerosols and liquids for household and personal care. The company supplies many leading supermarket and chemist chains in the UK and Europe.
The hygiene standards practised within Nichol plant approach those of food manufacturing plants. So when the company encountered a problem of carbon steels corroding in steamy water test baths they needed to do something about it quickly. There are eight of the water baths in total, varying in length from just over three metres to nearly eight metres. On each tank chains are suspended between 25.4mm and 38mm above the water, which is kept at a temperature of 55°C - 60°C. The chains carry aerosol cans which are submerged in the soft water for a pressure test lasting three minutes. Once immersed, the water temperature raises the vapour pressure of the gas within the container to test it for leaks.
Plate 1 Tsubaki's WP Chain
The problem of corrosion was related to the constant effusion of steam rising from the baths. Over time this caused the original carbon steel chains to "corrode red raw rusty"according to Peter Gough the maintenance engineer responsible for the plant. In an effort to overcome this problem the carbon steel chains were replaced with stainless steel units, These resisted the corrosive conditions but their strength and elongation characteristics were found to be inadequate for the application.
Local Tsubaki distributor Bearing Power was called in to look at the application and suggest a solution. Following a joint visit from the Bearing Power and local Tsubaki representatives Tsubaki's WP chain was recommended.
The qualities claimed of WP chain mean that it solves corrosion problems where stainless steel chain does not provide the strength needed for the application, or necessitates the use of an unacceptably large chain size. WP chain is also stated to be the ideal solution where carbon steel chains must be replaced frequently, due to excessive corrosion, or where nickel plated chain is flaking and causing problems.
According to Tsubaki, WP chain offers the same high tensile strength and impact resistance of carbon steel chain, but a double surface finish, prior to assembly, means that its corrosion resistance is much improved when compared to standard roller chains,nickel plated chains and even zinc plated chains.
WP chain stands up to intermittent water exposure: from non-caustic indoor washdowns to outdoor elements, even salt water. It is reported that in tests, WP chains were immersed in salt water for eight days then removed for 16 hours to duplicate a typical working day. Even under this harsh operating regime the WP chain showed no signs of corrosion even after 14 days.
Following Tsubaki's recommendation, Peter Gough replaced the stainless steel chain on a single bath with WP chain. The results have been particularly encouraging: WP has coped with the corrosive soft and steamy water without problems, and the load capacity of the chain and its resistance to elongation has proved equal to that of previous carbon steel chains. The cost benefits of this to Nichol Beauty products, in terms of savings on replacement product and the labour required to fit it, are obvious. Indeed, on the strength of WP's performance the Thetford plant is planning to fit the chain to all of its eight water test baths.
Details: Tsubaki UK Ltd. Tel: 01949 838554.
