Liquid-Mounted Seal

Liquid-Mounted Seal

Maxwell Liquid-Mounted Seal (IFR Rim Seal)

Our liquid-mounted resilient foam-filled rim seal functions by thef resiliency of the inserted foam log, which permits the seal to adapt itself to minor imperfections in tank dimensions and in the tank shell. The foam log can be mounted above the liquid surface (vapor-mounted) or on the liquid surface (liquid-mounted).


Maxwell Floating Roof Rim Seals are custom designed to each individual tank within the requirements of API 650/653, BS 2654, EN-14.015 and EEMUA-159.

Maxwell Continental Tank Serv Engineering has combined over 20 years’ experiences from the past with their research and development, through which it has produced increasingly innovative products for reducing above ground storage tank (AST) emissions.

And it’s not just about the new and interesting, when old technologies and products are to be revitalised or re-used it always can be reviewed and when needed altered to be made more efficient.


Advantages Maxwell Liquid-Mounted Seals

The internal floating roof rim seal design is such that evaporative losses from the stored liquid are limited to losses from the rim seal system and deck fittings (standing storage loss) and any exposed liquid on the tank walls (withdrawal loss).

Having liquid mounted rim seals mounted on the liquid product surface creates a situation with no vapor space below the seal, thus creating an environment of up to zero emission.


Next to preventing vapour losses or preventing ingress of rain water the Maxwell floating roof rim seals will be provided as the right seal for every type of above ground storage tank (AST).

Due to years of experience in design, manufacturing and installation we as Maxwell will provide products that satisfy all protection needs.


As recognised by Maxwell Continental Tank Serv Engineering a competitive, cost effective and good working floating roof rim seal should comply to many basic criteria.

Since floating roof rim seal parts are in contact with product, Maxwell will design these parts as product resistant as possible.

During the sliding movement against the tank shell all sliding parts will be designed by Maxwell in wear resistant materials.

While the Maxwell floating roof rim seals are also designed to positively centre the floating roof, our design will prevent horizontal movements to damage tank features like rolling ladders, gauge poles, pipe drain systems and more. During the horizontal movements of the internal floating roof our Maxwell floating roof rim seals are designed to damp these horizontal roof movements to a minimum.

Based on our Maxwell design input the adequate working range of the floating roof will be analysed and the rim seal designed will be evaluated to comply to the working range needed by the current tank configuration or any local laws or guidelines. This means we can provide each seal with a working range compliant to your request, from API where a range of +/- 4″(102-mm) is required or per EEMUA 159 or NEN-EN 14015 where a tank seal working range of -X/+3X might be requested.


For the secondary rim seals Maxwell will provide the secondary rim seal exposed material in a configuration, which will meet or exceed any requested fire-retardant level.

In the meantime, Maxwell will always design any secondary rim as low as possible to allow more filling capacity.


Maxwell Liquid-Mounted Seals

The most commonly used Maxwell Liquid Mounted Seals either normally used in a combined configuration are:

• MRS-7/350 Primary Foam Filled Seal


All Maxwell IFR Rim Seals can be combined with;

• MRS-70 Secondary Wiper Seal


Finally, when the local requirements are pushing local terminals or refineries to add a tertiare or tertiary or triple rim seal, on request these extra rim seals can be provided by Maxwell.