Seals are small components that have a big function. At their most essential purpose, they keep fluid in and debris out. Failure to do this can lead to costly machine destruction, and even endanger the lives of people working around these machines. Preventing seal failure is very important on many different levels.
What Seals Are Up Against
Many factors can cause a seal failure. Being aware of these factors will help you in preventing an avoidable failure. Seals are under constant pressure because of the liquid or gas being contained. Typically, the seals in pipes or machinery have some type of matter within transferred at high velocities. This is a huge part of what they were designed to do, but too much or too little pressure could wear down the seals.
In addition, extreme temperatures can cause the seal to become brittle. A mixture of extreme temperatures and pressure is a recipe for cracking and leaking. Also, debris can contaminate the integrity of the seal. Even in clean environments, the small shavings from pistons or hydraulics can get into the seal. Chemical compounds can cause a much faster seal breakdown, so be aware of what type of matter stays concealed. Finally, time will cause the seal to break down. There is no way to avoid this one, so ensuring you mitigate the other factors can help the longevity of a seals life.
Different Types of Seals
Each seal has a specific purpose and function. Putting the right seal in the right environment will help you have a more successful operation.
- O-rings are the most popular type of seal. They are meant for static conditions and can conceal liquid and gas.
- Rod seals should work with hydraulic cylinders. They typically work best with concealing fluid and can withstand movement.
- Piston seals should also be used with hydraulics, but specifically pistons instead of cylinders.
- Wear rings find usage in sewage pumps mostly. They are used to decrease the leakage around an impeller, which is the rotor that increases the flow of liquid.
Preventing Seal Failure: How To
These are the main points of failure for seals and the best ways to avoid them:
- Install the seal properly. Even with improper installation, a seal can work initially, but it will fail much quicker. Seals need to have the exact size for a precise fit. Or they will fail. Make sure to get the correct seal for the area in which you plan to install it.
- Cleanliness is paramount. Although it is important to keep debris away from the seals, that is not where cleanliness needs to begin. You also need to make sure that the area is clean of debris during installation.
- Find the proper rating for the environment. Seals have different ratings for temperature and pressure. Make sure the seal can handle these two factors for longevity.
- The finish of the seal and the shaft need to match. You can’t have a smooth shaft with a seal that has edges or burrs. Anything that can be caught or cause friction will create debris. This mismatch can also throw the seal out of alignment.
- Ensure all other parts of the machinery are functioning correctly. An anomaly somewhere else can cause undue stress to the seals.
- Periodically check the fluid conditions. The purpose of a seal is to prevent leaks, but too much or too little fluid can cause damage. Verifying the fluid conditions stay consistent will keep the seal in good shape.
- Replace seals promptly. This one comes more with experience. Always replace seals before they get too worn to stay effective.
The original article was written by staff at Real Seal and can be found on their website here.
For more information about seal problems you are having and how Gallagher Fluid Seals can help, contact our engineering department.