Mechanical seals are very important in industrial operations, especially in machinery such as pumps and compressors, because they help prevent leakage of water, oil, air, or other fluids. Whether you are buying new hydraulic equipment or repairing the existing ones, it is paramount to check the seals and ensure they are working well. So, how well do you understand industrial seals? Here is a comprehensive guide to help you understand what they are, the main categories, and the factors to consider when buying them.

How Does an Industrial Seal Work

Industrial seals are devices mainly used in pumping equipment and applications. If you take a closer look at a pump, it contains two main components; the casing and rotating shaft. However, a third component, industrial seal, is also required to ensure the pump does not leak the medium being pumped. 

Seals were discovered in the early 20th century, but their use became more pronounced during and after WWII. A mechanical seal contains the following elements: 

• Rotating part 
• Spring 
• Grand plate
• Stationary component (the seat)
• Stationary component (sealing member)
• Clamp ring 

The seal located between the stationary component and the rotating one is referred to as the "primary seal" and is often considered the most crucial one. A "secondary seal," commonly referred to as O-Ring, sits between the shaft and the sealing member. 

The spring helps to maintain pressure on the primary seal to ensure that no space that can cause leakage is left between the shaft and casing. The primary seal is made using a wide array of materials, such as Tungsten carbide, Silicon carbide, or Alumina Graphite. 

The commonest type of industrial seal is the pusher model, which uses a secondary seal that moves axially on a shaft with contact on seal faces. The movement helps to accommodate wearing and also cater to possible gaps created by shaft misalignment. These seals are inexpensive and also come in different sizes. Other industrial seals include the multiple seal design, non-pusher type, cartridge seals, single spring seals, and dual seals.

Things to Consider when Buying Mechanical Seals

Now that we have listed the main categories of industrial seals, the last question might be, “How do you select the best?” Here are some of the main considerations to factor when buying seals: 

• Dimensions 

It is prudent to establish the dimension of the machinery, especially the shaft and bore sizes, and go for the perfectly fitting seal. You might want to look at the manual of the equipment or work with a technician to determine the correct size of the seal. 

• The Media that You are Pumping

It is paramount to establish the media that you want to seal. Is it water, semi-solid, oil, chemical, or petroleum? The seals that you select should be able to prevent leakage without getting corroded or being negatively impacted by the medium. 

• Shaft Speed

The speed of the shaft of the equipment, from pumps to motors, is likely to have the same impact, just like temperatures and pressure. If your shaft will be running at a very high speed, make sure to go for a strong seal that can avoid tear and wear. 

• Temperature and Pressure  

If the system's temperatures and/ or pressure will be very high, you need to pick a seal made of high-tolerance material. This will ensure that the seal and valves can operate optimally even at high temperatures to avoid compromising your system’s efficiency. 

• Compatibility 

This concept is often overlooked when buying seals, but you should always try to avoid using seals made from materials that are not compatible.  If the equipment will be flushed, the gases or liquid to be pumped should be determined to reduce the risk of premature seal degradation. 

This post has demonstrated that seals are critical for effective equipment functioning, especially pumps and compressors. Therefore, you should go for the model that is made to work with your type of material and machine. Remember to also purchase the seal designed by trusted brands for quality assurance and thereafter maintain your equipment in top condition for better performance.