Are you confident that your system is protected against a seal failure? If not, it could mean a significant setback in production and costs you didn’t have to spend. Protect the investment you invested in by taking these four steps.
1. Choosing the Right Seal
The application, operating conditions, and off-design usage of the seal must be considered carefully before purchase. Even if you simply need a seal to function in hot water, not any seal will do. Boiler feedwater, for example, will not properly lubricate and cool seal faces, resulting in premature seal failure if the wrong seal is installed.
The user must therefore determine that proper operating parameters are maintained. Then, contact must be made with the seal supplier to choose the correct American Petroluem Institute (API) flush plan, seal face combination, and elastomer. It is important to ensure that the proper seal is in place, since every application has its own unique requirements.
2. Proper Installation
Many seal failures could have been prevented simply by a proper installation. Too often, seals are installed without referencing the manufacturer’s instructions, or without taking the proper care to prevent damage on the seal faces or O-rings. Some of the more common issues include: forgetting to tighten set screws before removing setting clips, damaging O-rings, and not tightening gland bolts evenly. Many of these issues can be avoided simply by opting for a cartridge seal over a component seal. The cartridge seal has many of the delicate parts preassembled, reducing the chance for errors significantly.
3. Prevent Excess Heat Generation
Heat generation between seal faces can reduce a seal’s life dramatically by causing problems such as dry-running. The cause is often due to a flooded pump, or an incorrectly vented seal chamber before startup. Another cause might be shaft runout or elevated vibration.
For nearly every application, API 682 will almost always be recommended. No matter if you decide on Plan 11 (a flush line from pump discharge) or Plan 13 (recirculation to pump suction), these systems will keep the seal faces clean, cool, and well-lubricated. Your seal support system will also have an impact on the success of your system. Be sure to discuss these carefully with your seal manufacturer to ensure a cool-running seal.
4. Manage Proper Storage Conditions
Mechanical seals have many unique parts comprised of various materials. If you are not aware of the environments the seals must be stored in, the seals may lose a considerable amount of functionality due to the delicacy of their components.
The seals must be stored in a clean environment, where the temperate and humidity are regulated. If proper care is taken, seals may be stored effectively for up to five years.
Different steps must be taken depending on how long the seals will be stored. A new seal being stored for the next two years should be placed in a clean and cool environment. To prevent face lock and loss of face flatness, rotate the seal faces against each other using the sleeve or shaft two turns every three months, if the seal is not being used.
For new seals being stored for more than two years, or for a seal that has already been in use and will be stored for more than a year, the process is more complicated. Disassemble the seal, clean and dry every component, then store each of its parts individually. O-rings must be in a relaxed state, and placed in their proper environmental conditions, depending on its material. Plug all openings of the seal’s gland in addition to the pump’s seal chamber (if it has not been used). Seal faces should be separated and stored in separate bubble-wrapped packages.
When reassembling the seal after storage, check O-rings for cracks, cuts, and wear. Then, lubricate them to facilitate assembly. Be sure to replace damaged or compression set O-rings. Check the mating ring for cracks or chips, paying special attention to the sealing faces. Contact the vendor for a replacement if damage is found.
To purchase seal components or to learn more about them, please visit Real Seal.
