Processing equipment that come with pumps, compressors, and any type of rotating shaft also comes with mechanical seals. This is to reduce the emission of liquid outside the machine, preventing any visible leakage. With a mechanical seal, the environment is not only clean and hazard free but the integrity of the equipment is also protected so they last longer.

A mechanical seal is a very simple device and it comes with two flat faces that run against one another. While the rotating face is secured to the pump shaft, the stationary face is held properly in the gland. Since leaks are bound to happen in machines with pumps, the possible leakage path is sealed by a matted surface that is perpendicular to the shaft center. It is applied with a lubricating film for added protection against heat and friction. There are also other components to a mechanical seal that helps prevent leakage and these include an O-ring, metallic bellows, gaskets, and elastomers to name a few.

Mechanical seals rarely have problems and they do last longer than compression packing. But if they are failing too often, it is a good indicator that there is either a problem with the parts of the seal or in the process. Thus, monitoring and maintenance of the seal is a great way to solve problems and improve the efficiency of your machines.

The Importance of Maintenance

A failing mechanical seal often leads to wasting money. First, companies end up losing a lot of revenue because of the halt in the production and replacement of the damaged machines. Next, there is also a loss of revenue caused by the downtime of repairing the machine as well as replacing the seal. Moreover, leaking requires the pump to be changed because the internal surfaces may have been damaged due to the presence of moisture. This means that the pump needs to be rebuilt aside from the seal itself. There is a lot at stake when mechanical seals break down.

To prevent the seals from failing, it is extremely crucial for them to undergo proper maintenance on a regular basis. However, it is also crucial to take note that improper mechanical seal maintenance can also lead to failure of the seal. Mechanical seal maintenance often involves removing parts and improper re-installation of the parts can cause them to not be aligned properly thus leading to too much train during the shaft movement. Moreover, mishandling of the seal and using the wrong lubricant during the maintenance can also result to the seal failure. It is therefore important that proper maintenance should be observed so that further damage will not be inflicted upon the mechanical seals.

Proper Mechanical Seal Maintenance

Different mechanical seals require different maintenance steps and while it is best to leave the maintenance to professionals, it pays to know about proper maintenance tips so that you will be able to know if your mechanical seals need maintenance or not.

• Learn the different symptoms of seal failure: You need to know the different symptoms of a seal failure before you implement the maintenance. The tell-tale sign of a seal failure is the presence of some leakage. The leakage can occur as a small tight spray outside the seal or a continual drip to a full spray. Do not wait for the seal to produce a continual drip to undergo maintenance.

• Lock the mechanical seals: When performing a shaft axial displacement adjustment, make sure that the collar screws are locked to prevent the seal faces from getting damaged due to exposure to environmental factors.

• Keep the ports on the gland plant plugged: When the mechanical seal is installed on the shaft, make sure that the ports on the gland plate are plugged before you connect the ports to the external seal piping.

• Use a hydraulic cylinder: For faster detachment and attachment of parts, use a hydraulic cylinder so that you not only save on time in these processes but you also ensure that the parts are properly aligned and secure.

• Remove the shaft deflection: Eliminate shaft deflection as much as possible during maintenance as this can cause a lot of strain to the mechanical seals leading to eventual failure in the future. To remove shaft deflection, use a C or D frame adapter or a pump center line to lessen the strain problems.

• Reduce the vibrations: Too much vibration can also cause a lot of damage to mechanical seals. Make sure that you reduce them by balancing the rotating components.

• Keep the pressure of the stuffing box within the seal limits: The pressure of the stuffing box should be within the seal limits to avoid pressure build up that can damage the seals. To do this, you can do discharge or suction recirculation to balance the pressure within the stuffing box.

The integrity of your pump relies heavily on the health of your mechanical seals. Make sure that you conduct proper maintenance as this is a more cost-efficient option than replacing damaged ones.

For additional information and resources regarding the families of rubber and plastic sealants, machinery, and laboratory testing, contact Real Seal today.

Pumps are devices that move liquids or gasses by mechanical action. For the pump to work, it needs to be sealed completely tight to avoid leaks from occurring. In the past, pumps were sealed using rings, however rings were not effective in protecting the device from leaks. Today, most pumps are sealed by mechanical pump seals that are more competent in preventing leaks from happening.

Benefits of Seals

Leaking is the primary issue that is addressed by seals. The most obvious benefit of seals is that they allow pumps to function leak-free. So, if you are still using packing seals, then it is time that you switched to mechanical seals. Below are the benefits of mechanical pump seals.

• Having less fluid loss in a machine means better savings in terms of repair work due to pump failures. Moreover, they reduce the number of hazards that can put the lives of the pump operators in danger. Less leakage means fewer incidents of falling and slips due to the wet floor. It also reduces the potential of harmful emission, if the pump is housing toxic chemicals.

• Pumps do still have leaks, just not visible leaks. Experts approximate “healthy” and acceptable leaks to half of a teaspoon a day under normal operating procedures. Most machines will recapture the lost air and condense it.

• Seals can adjust to different faces of wear as they come with inboard springs. This reduces the necessary daily maintenance that needs to be done for the seal to work optimally.

Elements of A Seal

Seals allow the pumps to work by reducing downtime caused by leaks. They are commonly applied to contain any liquid or gas within a vessel where there are rotating shaft and a stationary housing. But how do seals protect the pump? Simple, they comprised of elements that would protect the machine against leaking. Below are the elements of mechanical seals.

• A set of primary sealing faces: A mechanical seal is made up of a set of lapped faces to minimize leaking. Different faces are made from different materials such as carbon-graphite and ceramic to prevent them from adhering to one another. Different materials are made so that they can perform different functions. For instance, one face of the housing is held stationary while the other one rotates along with the shaft.

• Static seals: Mechanical pump seals also come with a set of static seals like V-rings or O-rings to provide secondary protection against leaks.

• Spring: To create face contact, seals often come with a spring member which include either single or multiple springs.

• Other hardware: Seals are also made from other hardware which include gland rings, shaft sleeves, compression rings, pins, and collars.

Things to Consider When Looking for Seals

There are different mechanical pump seals out there on the market, but before you decide on which one to get, there are three important things that you need to remember when looking for mechanical seals.

• Seal faces need to stay together. If they open, leaks will occur thus allowing solids or contaminants to enter between the faces. Entry of contaminants will likely destroy the lapped surfaces not only of the seal but also the pump.

• The seal materials should be compatible with any fluids that are being pumped through the system. These include cleaners, solvent, and steam. Using fluids that are not compatible may destroy the seal by disintegrating its components and cause leaking in the pump.

• Mechanical seals have a good seal life. They expire once the carbon face is worn out which usually happens after a long time.

How Seals in Pumps Work?

Mechanical seals are watertight fittings that are located between the fixed part of a rotating device and a shaft thus they are commonly used in pumps. It is important to stress the water-tightness of the pump. This is achieved using a fine fluid or film that is located between two friction faces to prevent the remaining fluid from passing. The film also works as a lubricant thereby reducing the wear and tear between the two lapped faces. With a mechanical seal, the pump can work naturally without the fear of any leaks.

Seals provide damage-free and leak-free performance for almost any solution. Thus, understanding the science behind it will allow you to optimize the use of the seal based on its design.

For additional information and resources regarding the families of rubber and plastic sealants, machinery, and laboratory testing, contact Real Seal today.