Maxwell Internal Floating Roof (IFR) Rim Seals
Normally our Maxwell IFR Floating Roof Rim Seals fall into three different types:
• Mechanical-Shoe seal
• Liquid-mounted seal
• Vapor-Mounted seal
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 Floating Roof Rim Seal types
Internal floating roofs typically incorporate one or two types of flexible, product-resistant rim seals: resilient foam-filled seals or wiper seals. Like those employed on external floating roofs, each of these seals closes the annular vapor space between the edge of the floating deck and the tank shell to reduce evaporative losses. They are designed to compensate for small irregularities in the tank shell and allow the roof to freely move up and down in the tank without binding.
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.
Secondary seals may be used to provide some additional evaporative loss control over that achieved by the primary seal. The secondary seal is mounted to an extended vertical rim plate, above the primary seal. Secondary is most commonly an elastomeric wiper seal.
For a given roof design, using a secondary seal further limits the operating capacity of a tank due to the need to maintain contact with the tank shell or keep the seal from interfering with IFRT fixed-roof rafters when the tank is filled. Due to these reasons secondary seals are not commonly used on internal floating roof tanks.
In the meantime, Maxwell will always design any secondary rim as low as possible to allow more filling capacity.
IFR Floating Roof Rim Seals
The most commonly used Maxwell Floating Roof Rim Seals either used as a single or combined configuration are:
• MRS-1/350 Primary Mechanical Shoe Seal
• MRS-7/350 Primary Foam Filled Seal
• MRS-60 Primary XPE Wiper Seal
All Maxwell IFR Rim Seals can be combined with;
• MRS-70 Secondary XPE Wiper Seal
Last but not least…
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.