High density Polyethylene (HDPE) tank systems overcome the persistent corrosion problems of stainless steel and mechanical failure of flexible bags.
HDPE, next to being versatile and durable, will ensure an almost condensation free environment for fuel and will provide water clean and free of any undesired taste for the galley. We have been involved in replacement tanks for boats previously fitted with mechanically unreliable flexible bags or stainless and aluminium tanks with electrolysis problems.
HDPE tanks are built in 8-12 mm thick HDPE sheets and are pressure tested to 0.2 bar equivalent to a fill point 2 metres above the tank. Higher pressures can be achieved and should be specified when placing an order. Standard specifications include baffles placed approximately every 300 mm which protrude through the top of the tank and are then welded. This is to prevent the top of the tank from “pumping” when under pressure.
The inspection hatches should be bolted on with fully encapsulated stainless steel bolts and gaskets should be made of resistant polymers like neoprene. The usual practice is to supply tanks with welded female thread sockets of gas pipe thread [*]. Different sockets, Metric, Special and Oversize, can be supplied to customers to fit their own fittings if need be. Different sockets, metric, special and oversize, can be supplied to customers to fit their own fittings if need be.
The tanks all have some sort of internal baffling to design specifications for two main reasons: firstly, to introduce rigidity to the tank, and secondly, to limit movement of contents. The baffles should have generous bores each in order to allow access from the inspection hatch to the adjacent compartments to facilitate cleaning and inspection.
Tanks built from rigid HDPE lend themselves to one-off production because there are no expensive mould tools to build. HDPE cannot be curved excessively for one-off applications, but multifaceted shapes normally solve most of the design problems.
HDPE tanks are ideal solutions for the custom and production boat builder for storing diesel fuel and fresh, grey and waste water. marineSOLUTIONS will be pleased to help with any design problems.
• Tanks for fresh water, diesel fuel, grey water and waste water.
Some Design Guidelines
1. Make sure the tank can be installed into the space it is designed for, i.e. will it go through the locker door/companion way? Make sure the tank can be easily removed.
Following information is required when seeking a quotation:
Dr. Yusuf Civelekoglu, CMI