How Mechanical Seals are Evolving

Rohith Ram

The consumption volume of mechanical seals is linked to downstream industries and international economy. As there will forever be some uncertainty within the international economy, the expansion rate of mechanical seals trade might not keep that quick. However, it has been forecasted that the market of mechanical seals remains promising. The product average worth declined within the past few years because of the technology development, the common worth can keep the trend within the few future years because of increasing mature producing technology and lowering price of raw materials.

COVID-19 will have an effect on the worldwide economy in three main ways: by directly moving production and demand, by disrupting supply chain and market disruption and by its money impact on companies and money markets. But the Mechanical Seals market is projected to reach $4610 Million by 2025, at a CAGR of 4.1 per cent.

“Based on the material type, metal seals are likely to remain dominant whereas plastic seal is to gain greater acceptance in the market, driven by the growing usage of plastic seals in e-commerce, retail industry, and pharmaceutical industry. They are also ideal for securing intermodal containers worldwide as they required a special bolt cutter for the removal of metal bolt seals,” says Stratview Research, a global market intelligence firm.

Some of the current trends and factors that are pushing the growth of the mechanical seals industry are as follows:

O-Pro seal: preventing leakage as a double seal barrier
One of the leading manufacturers of mechanical seals has introduced this product. O-Pro seal uses a series of O-rings to create a robust seal and lubrication chamber in a single piece seal. This new feature can be fitted throughout pumps which cover flows to 295 m³/hr, discharge pressures to 14 bar and liquid viscosities between 20 – 1700 cSt at temperatures between -15 degree Celsius to +175 degree Celsius.

The O-Pro Barrier seal which replaces both bushing and sealing equipment, packing or mechanical seal with a machined seal gland. This innovative design combines a bracket bushing and seal gland made of hardened cast iron with two sets of double O ring seals for reliable sealing and easy maintenance. The pair of static O-rings seal externally on the bracket and the pair of dynamic O-rings seal internally on the shaft preventing process fluid from leaking out of the pump and reducing wear between the shaft and the bushing.

The area between each set of inner and outer O-rings is filled with lubricating liquid, providing lubrication whilst also acting as a double seal barrier fluid to prevent leakage along the shaft. This is an important technology which is being adopted by many other companies and is driving the growth of the market currently.

Mechanical seals prevent pumps from leaking by containing the pressure of the pumping process and withstanding the friction caused by the pump shaft rotating. This leads to less wasted product, money saving, and less clean up. Mechanical seals are the most common cause of pump downtime and account for more pump repair costs than any other part of a pump. Therefore, it’s important that they are installed and maintained properly to prevent failures.

Here are some of the challenges that are to be looked out for.

Installation errors
Installation errors can easily damage mechanical seals so it’s incredibly important that mechanical

seals are installed by a professional and that the installation instructions are followed exactly. If a pump is started with an incorrectly installed seal major damage could occur and potentially damage other parts of the pump as well as the seal.

In recent years, scholars from all walks of life have performed research on mechanical seals and achieved various results. One of the research scholars in this field established a numerical simulation model of a noncontact mechanical seal considering the thermal deformation of the seal end face and the heat transfer of the film between seal faces. The results showed that thermal deformation cannot be ignored when designing mechanical seal structures under high operating conditions.

Another research scholar studied the vaporization evolution trend of film on a seal end face considering face deformation. Notably, a large temperature gradient can adversely affect the stability of the film at the seal face.

Poor or absent lubrication
A mechanical seal might fail due to poor lubrication or no lubrication at all. When there is no liquid around the seal it will be subjected to increased amounts of friction which will increase the temperature inside the pump. This rapid increase in temperature can cause burnt elastomeric parts and damage O-rings or rubber on the seal. This usually happens when there is no pumped medium in contact with the seal rings to transfer the heat.

Also, when lubrication is poor or absent mechanical seals made of hard materials will make quite a loud noise, this will cause parts of the seal to vibrate which can reduce the life expectancy of both the seal and the pump.

A recent research study has established a numerical model of multifield thermodynamic coupling. The correctness of the model was verified by experimental research, and the model was developed into software convenient for application.

Some of the future technologies that are to be looked for are digitalized pumps and on–board CM which would help in reducing the risks of leakage.

Digitalized pumps – an ideal solution to modernize industries
As the world adopts digital solutions such as IoT, data analysis and network connectivity into accelerating their operations, the pump industry is resorting to digitalization for better water management, identifying faults, capture live data and all the while through a remote monitoring option. Modern pumps are being developed to fit the needs of constructions of the future, where output is required to be delivered faster, with more competence; and integrating digital technologies into pumps is the potential solution to offer this.

The integration of IoT in such pump solutions develops a human-machine interface that allows for a closer look into operating pumps in real-time with lesser human effort. Smart sensors, a significant asset of IoT, is an example of this, which integrates embedded sensors and external sensor arrays. IoT’s interconnectivity creates a network of every device equipped with smart solutions for an ecosystem of wireless connections across a facility to work in agreement.

On-Board CM and Intelligent Support Systems: Prospective Technologies
On-board condition monitoring (CM) will help in reducing the expenditures associated with premature equipment failure or seal failure. It identifies the signals of poor performance and sends a signal to the operator to take necessary actions to rectify the parameters, which in turn significantly brings down the repair cost. This also saves costs associated with production losses.

However, mounting those devices or adding pressure switches, temperature switches or any relevant equipment without changing the seal design offers a tough challenge to seal manufacturers. Emergence of nanotechnology has resolved some of these hurdles. However, lack of availability of transmitters, proximity devices, and temperature and pressure sensors in a nano scale is still a prime challenge.

Future technologies that can convert these devices into nano components and incorporate them into mechanical seals are anticipated to increase adoption of on-board condition monitoring, which is expected to be a truly revolutionary development in seal construction and performance.

"Manufacturers that offer a comprehensive package constituting mechanical seals, aftermarket support, and diagnostic capabilities are at a competitive advantage. Mid-tier manufacturers must focus on research and development and innovation to gain a competitive advantage," states Frost & Sullivan Industrial Automation & Process Control Programme Manager Ashwin Annareddy.

With the future of the mechanical seals industry lying in the hands of researchers, the industry is expected to remain in progression in the long run notwithstanding the effects of the pandemic.