🧿1. How to repair a liquefied natural gas pipeline leak?

The repair method for an LNG pipeline leak depends primarily on the size and location of the leak, the pipeline pressure, and whether production can be shut down. The overall process is as follows:

1. Initial Response and Assessment:
Immediate Reporting: Upon discovery of a leak, immediately initiate emergency procedures and report it to the control center and safety department.
Isolate the area: Quickly evacuate personnel, establish a cordoned-off area, and eliminate all ignition sources (non-explosion-proof electrical appliances, tools, and mobile phones are strictly prohibited).
Assessment: Professionals will assess the leak's size, location, and form (whether it's a crack, hole, or flange leak).

2. Common Repair Methods:
Pressure Plugging (Non-Stop-Operation Repair): Suitable for pipelines where production cannot be shut down. This is the most common and technically demanding method.
Clamp Injection: The most popular method. A stainless steel leak repair clamp/fixture is manufactured or selected based on the shape of the leak. The clamp is then wrapped around the leak. A specialized sealant (low-temperature sealant) is then injected into the sealing cavity under high pressure through the injection hole on the clamp, forming a dense sealing layer to stop the leak. Steel Banding: Suitable for straight pipe sections with low pressure and small leaks. Use low-temperature-resistant steel banding with embedded sealing tape to tightly bandage the leak.
Wedge Plugging: For small holes, use wedge-shaped plugs made of special materials to temporarily seal the leak.
Suspension for Repair:
Stop, Drain, and Replace: If conditions permit, shut down the pipeline, drain the LNG into a storage tank, and then thoroughly purge and replace the pipeline with an inert gas (such as nitrogen) until the combustible gas concentration test passes.
Welding Repair: This is the most permanent and reliable repair method. However, it must be performed after the pipeline has been completely replaced and qualified, and performed by a welder certified in low-temperature pipeline welding.
Pipe Replacement: For severely damaged pipe sections, simply cut and replace them with new, prefabricated, qualified pipe sections.

For most emergency situations, using stainless steel leak repair clamps for pressurized sealing is the preferred option.

🧿II. Maintenance Precautions

Safety is the top priority during LNG maintenance. The following precautions must be taken:

1. Extreme Low Temperature Risk: LNG leaks can cause local temperatures to plummet to below -162°C, potentially leading to severe frostbite. Maintenance personnel must wear antifreeze gloves, face masks, and full cryogenic protective clothing.

2. Explosion and Fire Risk: LNG vapors, when mixed with air, form a flammable and explosive atmosphere. The following must be used:

Explosion-Proof Tools: Use spark-proof tools such as copper or beryllium copper alloy.

Static ESD Protection: Wear anti-static clothing and shoes, and ensure all equipment is properly grounded.

Gas Monitoring: Continuously monitor gas concentrations using combustible gas detectors throughout the maintenance area.

3. Asphyxiation Risk: LNG vaporization displaces oxygen, creating an oxygen-deficient environment in confined or low-lying spaces. Ensure adequate ventilation and wear a positive pressure respirator (SCBA) when necessary.

4. Technical Compliance:

Professional Team: This operation must be performed by a professional, experienced, and professional pressurized leak plugging company. Plan Approval: A detailed, approved work plan and emergency response plan must be prepared before construction.
Material Compatibility: All repair materials (such as leak repair clips and sealants) must be suitable for low-temperature operation (maintaining strength and elasticity above -196°C).
5. Post-Incident Monitoring: Completed repairs are not considered complete. The repair site must be continuously monitored (e.g., for temperature and signs of new leaks), and a plan must be developed for permanent repairs (e.g., welding) during the next downtime period.

🧿Third, Benefits of Using Stainless Steel Leak Repair Clips

Stainless steel leak repair clips (also known as "leak repair clips" or "pipe clamps") are core components for pressurized leak repair. Using stainless steel offers the following significant advantages:

1. Excellent Low-Temperature Performance: Austenitic stainless steels (such as 304 and 316L) resist brittle fracture in ultra-low-temperature environments and maintain exceptional strength and toughness, unmatched by other materials like carbon steel. 2. High Strength and Durability: Stainless steel's high strength allows leak repair clamps to withstand the high pressures of LNG pipelines. They are also corrosion-resistant and have a long service life, making them suitable for long-term or semi-permanent repair solutions.
3. Flexible Design and Reliable Sealing:
Customization: We can precisely design and manufacture the clamps based on the pipe diameter and leak point geometry (straight pipe, elbow, tee, flange, etc.).
Multiple Seals: Typically, designs feature two seals: an internal sealing strip (such as rubber or PTFE) and a glue injection groove. The sealant formed by the glue injection perfectly adapts to the shape of the leak, achieving a tighter seal with higher pressure.
4. Fast Installation: Compared to welding operations requiring production stoppages, leak repair clamps are significantly faster to install, typically taking from tens of minutes to hours, significantly reducing downtime and minimizing production and economic losses.
5. Safe and Efficient: Leak repair clamps can be plugged under pressure, eliminating the complex process of shutting down, draining, and replacing the leaks, reducing time spent working in hazardous environments, and enhancing overall safety. 6. Economical: While the cost of a single leak repair clamp may be high, the overall economic benefits are significant when considering the avoided production downtime, labor costs, and safety.

The housing is typically made of metals such as ductile iron and carbon steel, which are corrosion-resistant and high-strength. It can last the same life as the original pipe, eliminating the need for frequent repairs. Baoshuo brand carbon steel half joints are available in a variety of rubber materials, including NBR, EPDM, FKM, and silicone rubber. The half joint body is available in Q235 carbon steel and 304 and 316L stainless steel.

The following are Baoshuo brand oil-resistant pipe repair clamps, high-temperature-resistant pipe repair clamps, acid- and alkali-resistant pipe repair clamps, stainless steel pipe repair clamps, high-pressure-resistant pipe repair clamps, and large-diameter pipe repair clamps.

Summary

When dealing with LNG pipeline leaks, a safety plan, a professional team, and qualified materials are essential. Stainless steel leak repair clamps, with their excellent low-temperature performance, strength, sealing, and quick installation, have become one of the preferred technologies and most effective tools for emergency pressurized leak repairs in the industry, safely and reliably resolving emergencies without disrupting production.