What You Should Know About Mechanical Seal Repairs

by Mike H. Marketeer

If you’ve had a chance of visiting or working in industrial plants, you might already know how seals are important for industrial performance and productivity. Various manufacturing processes depend on the functionality of the mechanical seals, so you need to know how a mechanical seal degrades and when it’s the right time to replace or repair them.

1. Understanding Mechanical Seals

What’s a mechanical seal?

A mechanical seal is a piece of equipment that’s used in industrial plants to join systems together in order to prevent leakage. Mechanical seals are typically installed in industries, including but not limited to food processing, paper production, and chemicals and water supply.

Simply put, a mechanical seal allows the storage of fluid in a vessel—generally pumps and mixers. In these systems, the rotating shaft moves through a stationary housing, and the hosting rotates around the shaft.

Why Mechanical Seals?

When you seal a centrifugal pump, you need to let a rotating shaft enter the wet portion of the pump, while preventing the leakage of pressurized flow. This is where a mechanical seal serves its purpose. It’s placed between the pump housing and the shaft.

Previously, the traditional method employed for this purpose was gland packing. These days, however, more and more industries prefer to use mechanical seals, because when using gland packing, the shaft’s friction whittles away over a short period. Because of this, you only need to flush large quantities of water to keep it cool.

Besides, when using the gland packing method for sealing, you need to press the packing firmly against the shaft to avoid leaking. To accomplish this, a greater amount of drive power is required, which results in energy wastage.

In addition to this, the contact of the packing with the shaft wears a groove into it, making repairs or replacement a costly process.

The mechanical seal design helps in overcoming this issue.

Mechanical Seal Design

A mechanical seal essentially consists of three parts—the stationary part of the seal that’s adjusted to the pump with a static seal, which is then sealed with the gasket or an O-ring, fastened between the pump housing and the stationary part.

Generally speaking, the seal’s rotator portion is sealed with the shaft with the help of an O-ring. Since this sealing point rotates with the shaft, it’s regarded as static.

To accommodate shaft deflections that may take place due to the bearing tolerances, one of the seal parts is spring-loaded and mounted.

When to Repair a Mechanical Seal

The performance of a mechanical seal depends on various factors, such as operational conditions, face contact conditions, and their structural configuration, etc. If the mechanical seal doesn’t work properly, it results in pump downtime. You need to detect the fault effectively and repair the seal accordingly.

Deep Grooves On the Surface

The harsh materials in the process fluid often make deep grooves on the seal face. If you notice such grooves, try to address the problem before it gets too late.

Use an appropriate seal flush plan and flush the seal accordingly. Try to prevent crystallization or scaling on the seal face during the process. Use the seal face materials that can accommodate the buildup of crystalized media.

Uneven Wear Track

The contact between the seal rings can sometimes cause distortions and uneven wear track because of excessive pressures, clamping, or overtightening. Other reasons that may cause uneven wear track may include high temperatures or a shorter hard face.

To ensure the proper running of the seal for a longer time, always read the installation techniques and guidelines or seek help from a professional. Make sure that you’re using the seal under the recommended operating conditions.

Cracked Seal Face

A seal face can get fractured because of a thermal shock or a mechanical seal impact. Fractures and cracks start appearing due to overtightening and can be prevented by eliminating the cause of impact or shock. Try to follow an appropriate seal flush plan for your respective seal.

Chipped Seal Ring

Typically, chips and cracks take place in a seal face because of improper installation or mishandling of the seal parts.

Chipped rings can significantly deteriorate the pump’s performance. Therefore, if you notice this problem, try to acquire repair services urgently.

How to Repair a Mechanical Seal

Looking for an adequate mechanical seal rebuild? If you want to properly repair mechanical seals, seek help from a reputable company that uses premium quality materials and employs state-of-the-art methods to rebuild and repair them. Try to visit the facility and make sure they implement on-site engineering tools and finite element analysis to assess the device’s performance and predict its behavior.

Robco of America manufactures, rebuilds, and repairs mechanical seals at cost-effective rates. They provide premium engineered sealing solutions and mechanical seal repair services in Texas. They also offer custom-design mechanical seals for their clients. Contact them if you’re looking for reliable seal repair solutions.