John Crane has introduced the Type 8628VL, an advanced mechanical seal designed to tackle the oil and gas sector’s most demanding requirements. Engineered for ethane and ethylene pipelines that experience fluctuating pressure and temperature, this next-generation seal utilizes spiral groove non-contacting technology to enhance reliability, operational efficiency, and environmental compliance.
Ethane pipelines face complex challenges as fluid phases shift between liquid, vapor, and supercritical states, often compromising conventional seals. The Type 8628VL resolves this by using dual non-contacting seal faces arranged in a tandem setup. Peer-reviewed research published in Lubricants (MDPI) confirmed that spiral groove non-contacting faces offer superior hydrodynamic lift, phase-change resilience, and zero-wear performance, allowing pipelines to operate without friction and wear while utilizing process fluids as lubricants.
An ethane transmission company along the U.S. Gulf Coast confronted operational issues caused by pressure variations during phase changes. Ethane, transitioning from liquid at ~18°C (65°F) and 40 bar (580 psi) to vapor at ~32°C (89°F), created sealing problems that affected uptime.
The operator deployed four Type 8628VL seals on pumps operating at approximately 1100 psi, with the units running continuously for three months, experiencing intermittent shutdowns. After this period, the results were highly positive, demonstrating reliable non-contacting operation across all phases—liquid, vapor, and supercritical. The seals showed minimal leakage, and remarkably, there were zero failures during the entire operation. The performance exceeded expectations, providing the operator with a dependable and robust sealing solution that ensured smooth operations.
A senior reliability engineer overseeing the deployment commented, “The performance is exactly what we expected – consistent, dependable, and robust. We now have full confidence in maintaining uptime.” This performance consistency played a key role in improving overall system reliability, reducing the likelihood of unscheduled maintenance and enhancing the operator’s operational confidence. As a result, the company was able to minimize downtime and ensure a more predictable operational schedule.
The Type 8628VL seals also had a significant impact on service turnaround times and maintenance efforts. The improved performance of these seals led to a reduction in refurbishment needs and lowered overall maintenance costs. By addressing a primary cause of premature seal failure, these seals contributed to a more efficient operation with fewer disruptions, further enhancing the bottom line and long-term cost-effectiveness.
The Type 8628VL seals offer several key benefits, starting with enhanced reliability. They have nearly double the lifespan of conventional wet seals that use liquid barriers, with a mean time between repair (MTBR) of over 48 months. This exceptional durability means less frequent replacements and a more reliable sealing solution over time, leading to fewer maintenance interventions and reduced operational downtime.
In addition to their durability, the Type 8628VL seals are more efficient and sustainable compared to traditional options. They require only 2-3 gallons per minute (GPM) of flush fluid, a fraction of the 10-30 GPM needed by contacting seals. This significant reduction in fluid requirements translates into smaller system size, reduced capacity demands, and overall cost savings in both system design and operation.
Finally, the Type 8628VL seals simplify support systems by utilizing a dual, unpressurized configuration. This design eliminates the need for complex API Plan 54 or 53B setups, which typically require liquid barrier fluids and associated cooling systems. As a result, the operator benefits from a more straightforward and cost-effective sealing solution with fewer components to maintain, further enhancing the system’s efficiency and reducing operational complexity.
“Unlike hybrid or contacting seals, the Type 8628VL delivers true non-contacting performance, even during rapid phase changes,” said Mike Eason, Chief Technology Officer at John Crane. “This represents a major advancement for the industry.”
He added, “We remain committed to expanding our portfolio with solutions that support customer reliability and energy transition objectives. The Type 8628VL stands as a testament to our dedication to innovation, efficiency, and achieving zero greenhouse gas emissions.”
John Crane is a global leader in mission-critical technologies for the energy and process sectors, specializing in rotating equipment such as mechanical seals, couplings, filtration systems, and advanced asset management and digital diagnostic solutions. With a legacy built on innovation and a strong focus on service excellence, we have supported reliable and sustainable operations for our customers for more than a century.
While acknowledging the importance of traditional energy sources, we are driving the development of cleaner alternatives and shaping a sustainable energy future. Our expansive global footprint reinforces our commitment to customers, with more than 200 service centres across 50 countries. Generating over £1.1 billion in revenue in 2024, we form a key part of Smiths Group plc, a FTSE 100 listed industrial technology leader dedicated to engineering a better tomorrow.
