CavMac’s Innovative Floating Roof Drain Hose Assembly System


An external floating roof tank is a large cylindrical container, commonly used for the storage of petroleum products, which is capped with a roof that floats on the surface of the contained liquid substance. As the liquid rises, so too does the roof. However, a disadvantage of this system is the possibility of rainwater accumulating on top.

While there are options to remove this rainwater using articulated straight length steel pipes with mechanical swivel joints, CavMac Industrial Hose Manufacturers offer Drain Hose Assemblies to extract excess water more effectively.


Our Floating Roof Drain Hose Systems are custom-manufactured to suit your specific external floating roof tank. These hose assemblies are supplied with internal lead ballast weights to rise or fall with the level of liquid within the container, and when installed in a loop arrangement, the hose will naturally follow the loop and avoid dragging across the floor of the tank when moving. By doing so, the hose lifespan is improved considerably.


CavMac manufactured drain hose assemblies for floating roof storage tanks all include a chain and clamp to support the weight of the hose dropdown from the roof. As the roof rises higher, more force is exerted on the hose connection, potentially weakening it if not supported. By adding a simple chain and clamp, this force is negated, increasing the life of the roof drain hose system and hence aiding in the removal of excess rainwater for many years to come.


We offer different hose assembly options for use with hydrocarbons of up to 50% aromatics and liquids with up to 100%. Both assemblies use alternative rubbers in their production which have been developed to resist chemical and mechanical damage. These hose systems can be modified to suit your preference using either built-in or swaged fittings.


Implemented to avoid twisting during installation is an added white or red longitudinal line. The innovative alignment stripe guides the hose installer to fit the hose in a way which no torsional stress is placed on the system.


To fulfil the capabilities required from our system in any floating roof tank, CavMac drain hose assemblies can be manufactured in up to 61-metre lengths with a 76 to 152-millimetre internal diameter or up to 40-metre lengths with a diameter of 203 millimetres.


For more information on our Roof Drain Hose Assemblies or to order your bespoke system, contact CavMac’s expert technical sales team on +353 (49) 555 2340 or today!