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Mechanical Seal Types

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    The early days of Cotter Marketing, which started out as Cotter Marine, in the service and maintenance of large tankers, provided the impetus for the company’s all-round expertise in sealing and packing, both in the shipping and in land-bound industries. Cotter’s impressive record in the industry has led to distribution rights with top manufacturers, such as Chesterton, Magnaflux, Tekhniseal, Greene Tweed, Devcon, and more. Our listings below include a full range of mechanical seal types for rotary shafts. These include, but are not restricted to Cartridge, Cassette, Split, Gas, and Component Seals.

    With all that training at our fingertips, we are ready and able to help. Your sealing decisions are, of course, industry-specific, and relate to your usage and operating environment. We’ve been there! We welcome any questions you may have about your plant’s sealing requirements.

    Take a look at our Mechanical Seal listings below. The variety of our mechanical seal designs covers all possibilities. Our technical advisors, many of whom have at least 20 years’ experience in the field, look forward to working with you, designing solutions for your particular industry and plant.

    Mechanical Seal Types - component seal

    Component Seals

    Replaceable Low-Cost

    Mechanical Seal Types - single mechanical seal

    Cartridge Seals

    Modular Design, Flexible Repair

    Mechanical Seal Types - Double cartridge seal

    Cassette Seals

    Reliability, Ease of Installation

    split seal

    Split Seals

    ​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​Simplified Installation

    gas seal

    Gas Seals

    High Reliability, Reduced Gas Use

    Benefits of Cotter Marketing mechanical sealing partnerships

    Think rotating equipment – think mechanical seals – think Cotter Marketing – think partnerships.

    The processes at your power plant, mines, food or pharmaceutical plants, and manufacturing plants, rely on rotary equipment. We are all aware of the challenges involved in keeping pumps, mixers, and turbines safe and clean. Operating in tip-top condition is essential. Much depends on the effectiveness of various sealing solutions. The Cotter Rotating Equipment Solutions team is here to advise, implement, maintain, and help you operate at full capacity with our cost-effective solutions.

    • We deliver pump sealing solutions that are tailored to your highly demanding environment.
    • Your rotating equipment will benefit from enhanced efficiency and long-term reliability.
    • The increase in maintenance reliability means extended equipment life, a reduction in bearing failures, and lower costs.
    • Superior mechanical sealing solutions lead to outstanding protection from erosion and abrasion.
    • We’ll come to you — for pump repairs and upgrades.
    • We increase “Mean Time Between Failure (MTBF) and provide maintenance training.
    • Our partnerships with top quality suppliers enhance our partnership with you.

    Mechanical Seals: The many different designs

    Mechanical seals are typically required where a rotator shaft enters the casing of a machine, for example, a pump. To familiarise yourself with our mechanical seal types, take a look at the listings. They vary quite extensively, depending on a number of factors:

    • Industry requirements
    • Materials used
    • Design
    • Ease-of-use
    • Cost
    • Special functions, such as self-alignment

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    Cartridge seals

    Cartridge seals are pre-assembled and can be easily installed. A skills base is required but does not need to be advanced. Both single and dual cartridge seals are available from Cotter Marketing. Dual mechanical seals are a must when hazardous fluids are involved in the process.


    • Chesterton 150 Single seal and Chesterton 250 General Purpose Dual seal are affordable and reliable versions of the single and dual mechanical seal designs. Both of these examples will lower your maintenance costs if you are upgrading from packing or from component sealing solutions.


    Component seals

    Component seals are so called because the static components and the rotary components do require separate assembly on the rotary shaft. This should be performed by a highly skilled technician. This type of mechanical seal design is less expensive, but provides high quality solutions.


    • The Chesterton 891 Rotary Inside Single seal, works with a variety of stationery seal rings, making it very versatile, and a fit for all DIN and ISO pumps.
    • For a stationery component seal, take a look at the Chesterton Self-Aligning Stationary seal (SAS). Its self-aligning functionality lets it neatly match all Chesterton rotating faces.


    Cassette seals

    The introduction of cassette seals into the market place was a further step along the path towards seal standardization by using a modular gland and cassette system. This has also allowed plants to decrease spares inventory.


    • The Chesterton S10 Single Cassette seal and Chesterton S20 Double Cassette Seal offer interchangeable glands, o-rings and seal faces.
    • Their robust design in conjunction with flush, quenchand barrier fluid ports makes these seals very versatile
    • The Chesterton S20 Tandem Cassette Double seal has a high flow pumping ring which ensures that the barrier fluid flow is constantly replaced with cooler liquid resulting in longer seal life.

    The cassette design, and the common universal gland of both the S10 and S20, make repairs a cinch, requiring a simple cassette replacement.


    Split Seals

    Ease of assembly and a major saving of time, are the most important advantages of split seals. The design involves a split of the seal into its two halves, which are then joined together on the shaft within the equipment. There is no need to otherwise assemble the seal or to disassemble the equipment. Although the concept of a traditional split seal design can lend itself to potential leaks, there is absolutely no concern about leaking when you purchase a patented, special-design Chesterton seal from Cotter Marketing. Their split seals are virtually leak-free, and their excellent record provides proof of this accomplishment!


    • The Chesterton 442C Cartridge Split seal is constructed with a short axial measurement and gland position flexibility. This serves to augment the other advantages of a cartridge split seal.

    Split seals are excellent solutions when fluid leakage prevention is a priority, such as in food, pharmaceutical, and many other industries using agitators or pumps.


    Gas Seals

    Gas seals are ideal for conditions that require a contaminant-free product, or for an environment that cannot tolerate any emissions. Traditional gas seals used a liquid barrier, whereas today, gas seals are sealed directly. Chesterton seals from Cotter Marketing have improved on the improvement! In the event of gas flow interruptions, a liquid barrier takes over. It restores the gas barrier as soon as the flow recovers.


    • The Chesterton 4400 Dual Concentric Gas seal reduces gas consumption by checking the pressure of the process, making the necessary adjustments to control the gas. Due to its compact design, it supports multiple equipment types, such as ANSI and API process pumps, mixers, and compressors.


    Frequently Asked Questions


    What is the difference between gland packing and mechanical shaft seals for pumps?

    Gland packing materials tend to suffer from wear and tear after a while. Packing materials are made out of soft and flexible materials. These materials wrap well around a rotary shaft but don’t really stand the test of time. They are, however, easy and low-cost to repair.

    Mechanical seals do the job well – that is – they seal. This keeps the environment around the processing equipment clean and safe. Mechanical seals are durable and rugged. They may be more costly at the outset, but in the long run, they will keep maintenance costs low in situations where strong sealing is required.


    What is the difference between component and cartridge seals?

    Component and cartridge seals are actually manufactured with the same components. As both names indicate, a component mechanical seal needs to be assembled by a knowledgeable technician prior to assembly; whereas a cartridge seal comes completely assembled as a complete unit. The implications of the two designs are quite easy to visualise. For example, the installation of a component seal is time-consuming, and is open to contamination. A cartridge seal, on the other hand, takes almost no time to install, and is protected from exposure to contaminants.


    Can you provide some examples of Cotter Marketing solutions for mechanical seals in rotating equipment?

    We provide a number of very successful solutions, some of which are custom-designed to suit the processes and industries of various production environments. The following is a short list of examples

    • We have provided a very flexible solution that utilises the features of a cartridge seal with split seal technology. You can envision a split seal as a type of subset of a cartridge seal, and the resulting combination brings excellent results.
    • We have solved the issues of gas seal technology when the flow of gas is interrupted. The gas can provide a dry barrier seal, providing a cost-effective solution to this issue.
    • Many process environments require strict processing control. We have come up with a number of solutions for protecting the environment from contamination, and keeping it clean and safe. This results in equipment that can be depended upon for longevity and reliability.

    Let’s work on your solutions together

    Take a look at our selection of mechanical seals, then contact us to set up a Call Back session.

    Cotter Marketing has a strong background in the inner workings of seals, packing, and gaskets. This experience has segued into marketing partnerships with leading manufacturers of the type of equipment in which the company was so fully immersed. Let us share our knowledge and our partnerships with you.

    No solution is too complex for us. We are here to help with your sealing designs, including mechanical seals, gaskets, pneumatic seals, hydraulic seals, and pumping solutions. We also specialise in non-destructive testing, industrial lubricants, and metal and concrete coating.

    It’s time. Contact us now!