John Crane Launches Mechanical Seal for Ethane, Ethylene Pipelines: Type 8628VL

John Crane unveiled the Type 8628VL next-generation mechanical seal, which is designed to maintain seal integrity in multiphase ethane and ethylene pipelines under volatile pressure and temperature conditions. It deploys spiral groove non-contacting technology to ensure operational reliability, efficiency, and environmental compliance.

"Unlike hybrid or contacting seals, the Type 8628VL delivers pure non-contacting operation, even during rapid phase transitions,” said Mike Eason, Chief Technology Officer at John Crane. “It's a significant step forward for the sector. We will continue to expand our portfolio with products that meet customer reliability and energy transition goals. The Type 8628VL is a testament to our commitment to innovate for greater efficiency zero greenhouse gas emissions.”

Ethane pipelines experience frequent fluid phase change from liquid to vapor to supercritical, potentially compromising traditional seal performance. The company’s new seal counters this issue by using dual non-contacting seal faces in a tandem setup—a design verified by peer-reviewed lubricants research. The research validated that spiral groove non-contacting seal faces provide better hydrodynamic lift, phase-change resilience, and zero-wear operation in turbulent fluid applications. This allows ethane pipelines to eliminate friction and wear while using process fluid for lubrication.

Type 8628VL mechanical seal | Image Credit: John Crane

Use Case

A major ethane transmission company on the U.S. Gulf Coast encountered a significant operational challenge: managing phase change while pumping with pressure variations. Ethane exists as a liquid at approximately 18 ^oC (65 ^oF) and 40 bar (580 psi), but transitions to vapor at about 32 ^oC (89 ^oF). The phase change creates sealing and reliability challenges, negatively impacting uptime and seal lifecycle.

The company installed four Type 8628VL seals on inconsistent ethane pump equipment operating at approximately 1,100 psi. Following three months of continuous operation and intermittent shutdowns, the results showed:

• Non-contacting performance across liquid, vapor, and supercritical phases
• Very low leakage
• Zero failures

The installment also delivered measurable improvements in service turnaround, local service center support, and minimized refurbishment times. It lowered complex refurbishment costs, and the multiphase capability eliminated premature seal failure. Overall, key benefits include:

• Enhanced reliability: Operates about twice as long as conventional wet seals with liquid barrier fluid, with a mean time between repair (MTBR) of up to four years and beyond.
• Efficiency and sustainability: Requires only 2 – 3 GPM of flush fluid, less than the 10 – 30 GPM of fluid needed for contacting seal faces. This reduces the size, capacity, and total cost of fluid-flush systems associated with contacting seal technology.
• Lower operating costs: Needs minimal maintenance with a targeted MTBR of four years and beyond.
• Simplified sealing support systems: A dual unpressurized arrangement eliminates the need for API Plan 54 and 53B systems and cuts out liquid barrier fluids and cooling water.

Upstream Sealing

In early June 2023, John Crane announced the launch of the Type SB2/SB2A USP seal. The product combines the dual cartridge Type SB2/SB2A seal with its upstream pumping (USP) technology. The sealing solution expands John Crane's current USP product portfolio by offering a more robust seal, suitable for the pulp and paper and mining industries where exceptional performance is required.

Ideal for use with environmentally hazardous and abrasive fluids, as well as slurry duties with up to 40% solids by weight and a solids hardness of eight Mohs, the Type SB2/SB2A USP seal is designed for pumps and other rotary equipment.The new seal offers the same benefits as other products in the USP line, including extended mean time between repair, significant water reduction, energy savings, zero emissions, and lower total cost of ownership.