Qingdao Luhang Marine Airbag and Fender Co.,Ltd

Leading Manufacturer of Marine Fenders,Ship Launching Airbags and Marine Buoys with High Quality and Good service.

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Donut Foam Fender
- Oct 23, 2017 -

Donut fenders are designed to float up and down with the tide on a circular mono-pile either driven into the bed or mounted on the face of a quay wall. Donut fenders are suited for lock entrances, turning structures, approach channels and breasting dolphins. Not only do Donut fenders rise and fall with the tide but due to the low friction guides located inside the fender they also rotate around the pile assisting in lining up vessels for mooring or guiding though a channel. 

Construction of a Donut fender is much the same as a Foam Filled Floating Fender giving them all the ideal properties for optimal, maintenance free use. As with the foam fenders any variation of size is feasible allowing the fender to be sized to fit its purpose, they are unsinkable and can be finished in a variety of colors. 

Generally Donut fenders are designed with residual buoyancy to present the berthing face above the water line but some installations have utalised separate buoyancy chambers and submerged bodies for low impacts, all variations are possible with this versatile fender. It is also possible to install any combination of mooring points or secondary fenders to the donut fender. These can be designed bespoke for your application.

Donut Fenders — Performance 

The performance of the standard size Donut fenders given below represents a small selection of sizes selected to give an indication of the performance of a fender as a guide only. Generally Donut fenders are designed on a project by project basis taking into consideration the required berthing energy requirement and the size of the pile the fender will be installed on. The installation pile can either be existing or if new then the final size of the fender can be determined taking into consideration movement and therefore energy absorption of the pile. 


Donut Fenders — Physical properties 

Generally Donut fenders are made to measure. We have therefore given the dimensions, weight and performance (table on previous page) in groups of sizes designed to be an indication of performance only. Precise design and finalised dimensions can be calculated with project specific pile dimensions and berthing energy/reactive load requirements. Please call us for a detailed design to suit your requirements.


Donut Fenders — Quality & Installation 


Our goal is to meet the ever growing needs of our customers through the on time delivery of error free products, quality assurance is instrumental in the pursuit of our goal. Through document data and process control we can review and act, allowing to continually improve our products and processes. Internal audits of these control procedures helps to maintain a high standard of manufacturing. The information obtained from the control procedures forms the basis of the Production Method Sheets (P.M.S.) systems helping us to train staff so specific manufacturing processes are adhered to and customer requirements are met. 


Installation of our Donut Fenders is very easy. The fenders will be delivered to site ready for installation on the fender piles. Once lifted over and lowered onto the fender pile the fender should be ready for use. Ballasting or trimming is not required as the fender will float at the designed level. Finally a capping feature can be placed over the top of the fender pile to finish the installation off. Maintenance of our donut fenders is very low as the internal bearings are designed to allow the fender to rotate and float up and down with the tide for a period of 20 years. Any additional equipment installed with the donut fender such as secondary fenders or mooring points should be maintained separately.