Czech Republic
Summary
A total of six live, active leaks were discovered in two-inch OD pipes operating at 45 psi (3 bar) within a natural gas utility system in the Czech Republic. The leaks were in three different gas boxes at a block of flats. Shutting down the leaking gas lines in order to replace the defective valves was not an option, as more than 100 customers would be without gas for the duration of the repair.
Benefits
- Complete, ready-to-use kit
- Saves time
- Immediate, permanent repair
- Repairs live leaks up to 125 psi
- Application temperature as low as 15⁰F
- Conforms to irregular shapes
- No VOCs
- No hot work
Benefits
- Water-activated outer wrap
- No pipe replacement
- Quick and easy installation
- No contractor required
- No shutdown or re-lights
- No special tools required
- No environmental hazards
Challenge
Repairing natural gas leaks is a challenge for utilities that are committed to providing customers with uninterrupted service. Leaks were located migrating around the threads of the shut-off valves. Gas leaking into the enclosed area around the valves can cause pluming, where any ignition source could cause an explosion.
To repair valves by replacing parts would have required cutting gas service to all residents and the entire building for many hours. After shut down and repairs, coordination efforts to re-light every gas appliance in 100 apartments would have been time-consuming and labor-intensive, delaying the restoration of service to residents.
The utility required an on-site, immediate repair that could be performed within a limited timeframe while safely keeping the service on line. TridentSeal from CSNRI, a product designed specifically to address field repair of thread fittings and pin holes, was chosen for the project.
Solution
The Trident family of products was specifically designed and tested for the natural gas industry. The TridentSeal system can eliminate fugitive methane emissions by effectively sealing active natural gas leaks. Repair kits include all materials for a permanent repair, including TridentSeal putty and TridentSeal outer wrap. The kits provide a complete, easy-to-apply solution without any interruption in service.
Application
The repair required two TridentSeal live natural gas leak kits. The shut-off valve and adjoining pipes were cleaned to remove any oil, paint, and other foreign matter using a specially designed “no-spark” brush, followed by the sanding cloth and solvent cleaning wipe -- both components provided in the TridentSeal kit.
A qualified applicator applied the TridentSeal putty adjacent to the leak point, then mechanically forced the putty into the leak using the TridentSeal pressure-sealing tape. In-field use of these materials is easy and effective, with both applied in less than 15 minutes.
After using a gas-detecting device to verify that the leak had been stopped, eight layers of moisture-cured TridentSeal outer wrap was applied to secure the repair system in place and reinforce the valve. Compression wrap was then applied to the repair and perforated to allow the naturally occurring gasses from the curing process to escape. After curing for 10 minutes, the compression wrap was removed.
Results
Each of the six leaks was permanently repaired with the TridentSeal composite repair system. Customers did not experience a service interruption and gas service was quickly restored to safe operation without the need to shut down and then re-light appliances for each individual resident. The repairs, which could have taken a substantial amount of time, posing additional inconvenience and risk to residents, were completed efficiently and cost-effectively within two hours with TridentSeal.
