Hydraulic hose assembly cleanliness – part 2
Published: 10 September, 2015
This is the second part of a short series of articles based on the British Fluid Power Association’s recommendations and best practice for hydraulic hose assembly cleanliness.
Bulk hydraulic hose (from source of manufacture)
Air or water used in the manufacture of hose that comes into contact with the hose bore should be filtered to
The established level of cleanliness should be maintained during transportation by adequately sealing the hose to prevent the ingress of environmental contamination.
Cut Hydraulic hose (from storage)
It should not be assumed that tier-2 distribution of bulk product would continue to maintain the medium sensitivity level of cleanliness. If it has not been requested at the point of purchase, or within the contract documentation, then it is recommended that the minimum level of tier-1 supply shall be the medium level. Supplied cleanliness level can only be by agreement between the stockist and the purchaser.
Connectors shall be delivered free of internal swarf, other loose particulate, plating residue and be compliant with the medium sensitivity level of cleanliness.
Storage, packaging and transportation of components
The supplier is to exercise care at all stages of the package, storage and transport processes to ensure that the required level of component cleanliness is maintained. More specifically, that responsibility includes the following:
• Providing adequate packaging for component storage and shipment.
• Using appropriate storage conditions.
• Using appropriate shipping methods.
If deterioration in component cleanliness occurs between the time of release by the supplier and the time of receipt by the purchaser, then the supplier and purchaser shall jointly investigate the cause and take corrective action. Storage periods for any product should be kept to a minimum. Stock rotation is therefore essential and the ‘first in/first out’ rule applied.
Hose and connectors shall be stored in a clean and dry environment – bulk hose shall not be stored outside.
Bulk hose should either have the ends capped, be kept in the original shipping carton, or sealed plastic wrap, until required to be used. The end caps prevent additional contaminants entering the coil of hose, including microbial contaminant.
Connectors shall be stored in sealed bags, boxes, or closed bin drawers. Special care shall be taken for connectors which seal on rubber seals, such as O-rings, bonded and other types of rubber seals shall be stored in a clean, dry, stable and dark environment so as to reduce the chance of degradation and prevent additional contamination of the product. It is best practice to store O-rings in the plastic bags that they are received in from the supplier.
Any items returned to storage (e.g. bulk hose) should first be cleaned and protected to prevent damage by the ingress of contamination and also to ensure that they do not contaminate other stored items.
All caps, plugs and other methods used to protect hose and end terminations from damage and the ingress of contamination should be stored in sealed bags, boxes or closed drawers.
Note: Unused powder free disposable gloves are often used on site to stop contamination entering.
The above information has been edited from the British Fluid Power Association’s guidance document BFPA/P111 ‘Recommendations and best practice for hydraulic hose assembly cleanliness’. The full document contains further information and clarification on a number of the points referenced above. For more information about the document and how you can obtain a copy, please contact the Association at email@example.com, or Tel: 01608 647900. More guidance from BFPA/P111 will be featured in the BFPA Top Tips page in the next edition of Plant & Works Engineering.