Revolutionising Pulp and Paper Mills: Cutting Water Usage, Costs and Downtime with John Crane’s Mechanical Seal Solutions

January 20, 2025

3 Minute Read

Pulp and paper mills are the backbone of their industry, with a complex web of centrifugal pumps required to keep every stage running—from pulping and bleaching to papermaking and water treatment. These pumps move everything from paper stock and chemicals to clean water, ensuring that each step of production flows smoothly. But specifying the right pump isn't enough. Mechanical seals and support systems are often the critical elements that drive cost savings, reduce downtime and keep plants environmentally compliant.

The Hidden Costs of Outdated Seal Technology

Despite their importance, pump mechanical seals and support systems are frequently overlooked. A typical mill might rely on hundreds of pumps and selecting the right seals for each can be challenging. Options include single or dual mechanical seals, each with unique water and pressure requirements for cooling, lubricating and flushing away impurities. Ignoring seals or using the wrong type can lead to excessive water consumption, costly repairs and fines for non-compliance with environmental regulations.

Water scarcity is a growing concern and leaks can result in large costs from wastage. For mills seeking operational resilience, upgrading to seal technologies like Type FFET cartridge seals, John Crane's SafeJet and John Crane's Safeunit™ can make a significant difference—helping to save water, reduce downtime and meet sustainability goals. Advanced sealing technologies can also reduce downtime - which can be as critical as reducing water waste. Mean time between repairs (MTBR) is a key metric for evaluating reliability and upgrading to mechanical seals like John Crane's technologies can significantly extend MTBR, reducing unplanned downtime and repair costs.

The Right Seal Makes a Difference: A Real-World Success

A prominent paper mill in Japan recently launched a cost-cutting initiative to boost competitiveness by reducing paper stock waste and cutting energy costs. The mill's engineers quickly identified inefficiencies in their gland packing, causing leaks and environmental contamination. To address these issues, they partnered with John Crane to trial an upgrade.

In 2019, John Crane installed its Type FFET single cartridge O-ring pusher seal on one of the mill's process pumps. The initial results were encouraging, leading to further upgrades across additional pumps. By the end of 2020, the mill had installed three more of John Crane's FFET cartridge seals. The outcome was a significant reduction in pump operating time, saving approximately 403 hours per year per pump and a drop in energy costs totalling around $5,363 USD annually per pump. This upgrade cut costs and eliminated leakage-related contamination issues, enhancing the mill's environmental compliance.

The full case study can be read here or for more details on how John Crane solutions help drive efficiency across the industry, explore our collection of pulp and paper case studies.

Smart Water Management with John Crane's Safeunit Seal Support Systems

Water waste is another challenge in pulp and paper processing. Factors like temperature, rotation speed and mechanical seal pressure increase water usage. Without flow control, a seal may use 75 to 113 litres of water per minute—often far more than necessary. Reducing this waste is critical to cutting costs, ensuring regulatory compliance and maintaining operational efficiency.

One of Asia's largest paper manufacturers faced this issue where over 40% of water consumption came from 15 kraft paper production machines and more than 1,000 pumps. Leaks from improper flow control led to high water costs, safety issues and environmental concerns. By installing John Crane's Safeunit water control and monitoring systems, the mill cut water use by 76%. Safeunit by John Crane continuously monitors and adjusts seal water flow and pressure, creating optimal operating conditions for increased process efficiency and sustainability. Read the full case study on this paper manufacturer here.

Complementing systems like John Crane Safeunit, Upstream Pumping technology further enhances water management by creating a sealed fluid barrier. This innovation significantly reduces water use while maintaining optimal operating conditions for process pumps.

Drive Efficiency and Sustainability with John Crane

These easy-to-implement solutions offer significant benefits to pulp and paper mills of all sizes. Even smaller mills with just 46 pumps can save up to 3.8 million litres of water annually by upgrading to advanced seals and support systems. Beyond water savings, reduced leaks and downtime directly enhance profitability and lower environmental impact. John Crane's tailored solutions are designed to improve water efficiency, cut costs and boost reliability - to see how our technologies can support your mill's success, visit our pulp and paper industry page.

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