🧿1. Analysis of Causes of Flange Leakage

1. Gasket Failure (Most Common Cause)
Improper Selection: The gasket material, model, or pressure rating used is not compatible with the media (corrosiveness, temperature, and pressure).
Improper Installation: The gasket is misaligned, contaminated or damaged, or the gasket is reused.
Aging Failure: The gasket material loses its elasticity, becomes brittle, or cracks due to prolonged exposure to heat, pressure, or media corrosion.
Insufficient or Excessive Compression: Insufficient bolt preload results in a poor seal; excessive preload causes the gasket to collapse and lose its resilience.

2. Bolt Problems
Uneven Preload: Failure to tighten bolts in a diagonal pattern results in uneven force on the flange surface, causing warping.
Loosening: Thermal expansion and contraction caused by pipe vibration and temperature fluctuations can reduce bolt preload.
Corrosion or Stretching: Corrosion or elongation of the bolts due to long-term stress can lead to insufficient clamping force.

3. Piping System Problems

Pipeline Stress: Misalignment of pipes during installation or insufficient thermal compensation can cause significant stress on flanges, leading to deformation and leakage.
Severe Vibration: Pipeline vibration caused by equipment such as pumps and compressors can accelerate bolt loosening and gasket failure.
Temperature/Pressure Fluctuations: Frequent temperature and pressure fluctuations (water hammer, thermal shock) can fatigue gaskets and bolts.

🧿II. Flange Leak Treatment Methods

Depending on the leakage volume, media, pressure, and production requirements, treatment methods can be divided into two types: shutting down the machine and plugging the leak under pressure.

(I) Shutdown and Repair Method (Traditional Method)

When conditions permit shutdown, thorough treatment can be performed:

1. Bolt Tightening: For minor leaks, first try tightening the bolts evenly in a diagonal pattern. Be careful not to overtighten to avoid crushing the gasket.

2. Gasket Replacement:
Shut down the machine, relieve pressure, and drain the media.

Loosen and remove all bolts. Clean the sealing surfaces of both flanges to ensure there are no old gasket residue, rust, or damage.

Check the flange surfaces for flatness. If any defects are found, repair or replace the flanges.

Install new gaskets of the correct type and align the flanges.

Tighten the bolts evenly in diagonal order to the specified torque.

3. Repair or Replace the Flange: If the flange sealing surface is severely damaged or deformed, machining repair or complete replacement is required.

(II) Non-Stop Pressure Leak Plugging Method (Online Repair)

If production cannot be stopped, the following techniques can be used:

1. Using a Pipe Repair Clamp (Clamp-Type Leak Plug): This is currently the most commonly used and effective online repair method.

2. Injection Pressure Leak Plugging:
Install a special clamp around the leak point and wrap it around the flange.

Inject a special sealant into the sealing cavity under high pressure through the injection port on the clamp.

The sealant solidifies within the cavity, forming a new, dense sealant, thereby eliminating the leak.

This method is highly technical and requires specialized personnel and equipment. 3. Bundling/Pressure Sealing Adhesive:
Suitable for low-pressure, room-temperature leaks.
Use a bandage or steel tape impregnated with a special sealing adhesive and quickly wrap it around the leaking flange. Once the adhesive cures, a seal is achieved.
This is a temporary, emergency measure.

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🧿3. Advantages of Using Pipe Repair Clamps (Clamp-Type Leak Stoppers)

Pipe repair clamps are a type of sleeve-type device designed specifically for quickly repairing leaks in pipes, flanges, and other areas. For flange leaks, there are specialized flange repair clamps.

How it works: A two-piece repair clamp is wrapped around the leaking flange. By tightening the bolts on both sides, the sealing element inside the repair clamp (usually a high-quality rubber seal or gasket) is compressed, tightly fitting against the pipe and flange walls, creating a new, solid seal and effectively stopping the leak.

Main advantages:

1. Fast and efficient, significantly reducing downtime losses:
No production interruption, no pressure relief, and no hot metal welding required.
The installation process is simple, typically taking only 30 minutes to 2 hours to complete. This allows for rapid resumption of production and minimizes the significant economic losses caused by downtime. This is its core advantage.
2. High Safety:
The entire repair process is performed under pressure, eliminating the fire and explosion risks associated with traditional welding.
Operators do not come into direct contact with the leaking medium, ensuring operational safety.
3. Reliable Sealing and Strong Adaptability:
The modular design and internal high-performance sealing materials are adaptable to a variety of media (water, oil, gas, chemicals, etc.).
It can withstand high system pressures and provide long-term, stable sealing.
It is highly tolerant of minor flange misalignment, gapping, or sealing surface damage.
4. Easy Installation, No Special Skills Required:
The ingenious structural design typically allows installation using only standard tools (such as a wrench), requiring far fewer skilled operators than specialized methods like injection-molded seals.
5. Economical:
While the single purchase cost may be higher than that of a single gasket, the overall economic benefits are significant when considering downtime costs, labor costs, and safety.

It can be used not only to repair flange leaks but also to repair holes and cracks in pipes, providing a versatile solution.
6. Environmental Protection:
It effectively prevents the leakage of harmful media, avoiding environmental pollution and product loss, and complies with environmental protection requirements.

Baoshuo's pipe repair clamps are available in stainless steel 304, 316L, and 2205, seawater-resistant stainless steel 2205, oil-resistant, and large-diameter flange repair clamps, depending on the media requirements.

Baoshuo's emergency repair clamps include stainless steel 304 and 316L pipe repair clamps, seawater-resistant, SS2205 stainless steel pipe repair clamps, oil-resistant pipe repair clamps, and high-pressure pipe repair clamps (100 kg pressure),and large-diameter flange repair clamps， depending on the pipeline's internal media requirements.

🧿Summary and Recommendations

Solution Scenario Advantages Disadvantages

Shutdown for Gasket Replacement Planned downtime; Need to thoroughly address the problem Complete solution, low cost Production downtime and long process

Injection-type leak plugging Critical, high-pressure, and high-risk flanges where downtime is unacceptable Reliable seal, suitable for high pressure and high temperature Complex technology, requires specialized personnel, high cost, and long preparation time

Pipeline Emergency Repair Joint Emergency repair where downtime is unacceptable; Minor flange defects Fast, safe, economical, and versatile High initial purchase cost

Conclusion: For sudden flange leaks during production, using a pipe repair joint is the optimal, fast, safe, reliable, and economical emergency repair solution. It has become a standard feature in emergency repairs in the petroleum, chemical, water, and gas industries.