In many industrial facilities, mechanical seals for pumps are still seen as an auxiliary or interchangeable component. However, from a technical perspective, the sealing system is one of the key elements determining a pump’s reliability, efficiency and safety.
The engineering behind the design and selection of a mechanical seal directly influences the equipment’s performance: from leaks or premature failures to energy consumption, maintenance costs and regulatory compliance.
As manufacturers of mechanical seals with different designs, at Lidering, we explain how to choose the right type of mechanical seal for a specific pump and thus avoid recurring problems on site.
What is a mechanical seal for pumps?
A mechanical seal is a highly engineered component whose function is to provide a seal between the pump’s rotating shaft and the casing, preventing leakage during operation.
Depending on the fluid, temperature, pressure, rotational speed or available lubrication, the sealing system for industrial pumps varies, so its design should be seen as an integral part of the pump design, not just as a component that is dimensionally compatible.
From a safety and quality perspective, it is essential to choose the mechanical seal as a highly engineered component, not as a universal standard part. If the person responsible (whether a plant, production or maintenance manager, or a technician) selects the wrong seal for a particular pump, this can cause serious problems, such as:
- Premature failures and recurring leaks.
- Increase in maintenance and repair costs.
- Unplanned pump stoppages.
- Safety risks, especially with hazardous fluids.
- Possible regulatory non-compliance.
Types of mechanical seals for pumps by industrial application
As manufacturers of mechanical seals, at Lidering, we offer a wide range of sealing solutions with different designs, adapted to a variety of industrial applications.
Our seal catalogue includes multi-spring seals, wave spring seals, metal or PTFE bellows seals and single-spring seals, allowing us to provide technical solutions for a wide range of operating conditions in industrial pumps. Within this range, models like LWS30, LMS20 and LMB85 allow the sealing system to be adapted to the type of fluid, pressure, temperature, operating conditions and maintenance requirements of each application.
The key is to analyse each application individually and select the seal structure that best suits those conditions, avoiding generic solutions that will cause operational issues in the long run.
Advanced materials for pump seals and regulatory compliance
Another key pillar of seal engineering is the selection of seal materials. Materials in contact with the fluid must ensure mechanical strength, chemical compatibility and, in many sectors, regulatory compliance.
That is why it is important that, based on the previously mentioned factors (temperature, type of fluid, pressure, lubrication, etc.), mechanical seals should include materials such as:
- Silicon carbide and tungsten carbide for seal faces.
- Components in PTFE or FFKM for chemically demanding environments.
- Special alloys like Hastelloy, Inconel, Superduplex or Titanium in metal components.
Knowing the best sealing material for each industry will ensure correct and safe application. This is the case, for example, in the food and pharmaceutical industries, where materials must comply with specific requirements, such as FDA regulations or EC 1935/2004.
Engineering applied to sealing: the competitive advantage of an expert pump seal manufacturer
Our long experience tells us that the difference between a mechanical seal that works and one that causes issues usually lies in the engineering applied to each specific case. At Lidering, the added value lies not only in manufacturing mechanical seals for pumps, but also in understanding the entire process in which that seal will operate.
Our approach starts with a technical analysis of the actual application: pump hydraulic conditions, fluid behaviour, operating conditions, possible misalignment, start-ups and shutdowns, and the chemical environment. From there, the design of the seal is adapted to minimise operational risks from the outset and avoid long-term issues.
This approach allows us to act as technical advisers on sealing systems, working with design engineers, maintenance managers and plant managers to select or redesign the most suitable seal. Compared with standard off-the-shelf seal solutions, our customised seals allow us to:
- Adjust the seal architecture to the actual working conditions.
- Select materials based on the process, not just the fluid.
- Prevent common failure modes before they appear on-site.
- Provide technical support to the customer throughout the component’s service life.
This accumulated knowledge in multiple industrial sectors is what makes the mechanical seal a risk control tool, rather than just a wear item.
Common pump failures caused by poor seal engineering
A significant proportion of problems with industrial pumps do not stem from the pump itself, but from a poor choice of mechanical seal. When the sealing system does not perform correctly because of incorrect sizing or poor adaptation to the actual application, failures recur and almost always follow the same pattern.
Some of the most common failures resulting from poor sealing engineering are:
- Premature wear of the seal faces, caused by insufficient lubrication, incompatible materials or incorrect hydraulic balance.
- Persistent leaks, which cannot be resolved with simple adjustments or replacements because the root cause lies in the seal design.
- Overheating of the sealing system, especially in applications with low-lubricity fluids, high speeds or high pressures.
- Unplanned downtime, with a direct impact on production, safety and maintenance costs.
These problems often worsen when “equivalent” or standard solutions are chosen without considering the pump’s dynamic behaviour or the application in which it is used.
Case study: mechanical seal engineering applied to centrifugal pumps
The importance of proper mechanical seal engineering is clearly reflected in real plant applications. An example is the project developed by Lidering in the supply of cartridge mechanical seals for ANSI centrifugal pumps, where the challenge was not just to replace a component, but to solve a recurring problem of operational reliability associated with the sealing system.
In this real-life case, technical analysis of the application made it possible to identify the causes of the failures and to devise a sealing solution tailored to the actual operating conditions: type of fluid, operating regime and maintenance requirements. Following this assessment, a mechanical cartridge seal capable of meeting the specific requirements of the process was selected and installed.
The result was a direct improvement in equipment reliability, fewer leaks and fewer corrective interventions, demonstrating how sound mechanical seal engineering reduces risks, optimises maintenance and improves process stability.
In summary, if you need to assess or redesign the sealing system for a critical pump at your plant, the technical team at Lidering can help you analyse the application and identify the most suitable solution from an engineering perspective.
