Underground Valve Chamber Protection
China Gas Buried Valve Protection Program
A petrolatum tape-based protection system has been used for buried valves and connected components across three China Gas project sites since 2018.
- Client
- China Gas
- Industry
- Natural Gas Distribution
- Location
- Nanjing, Hangzhou and Yangzhong, China
- Project date
- In use since 2018
- System
- Petrolatum Primer / Profiling / Sealing Mastic / Petrolatum Tape
Verified project record
Project overview
Application and project record
- Client
- China Gas
- Industry
- Natural Gas Distribution
- Asset type
- Buried Gas Valves, Flanges and Valve Chambers
- Protection system
- Petrolatum Primer / Profiling / Sealing Mastic / Petrolatum Tape
- Location
- Nanjing, Hangzhou and Yangzhong, China
- Project date
- In use since 2018
Project summary
Scope and application context
China Gas operates underground valve chambers where rainwater ingress, groundwater seepage and standing water can create a demanding corrosion environment for valves, flanges, bolts and connected pipework. A petrolatum tape-based protection system has been used across project sites in Nanjing, Hangzhou and Yangzhong since 2018.
Project challenge
Protection requirement
Underground valve chambers can retain water and moisture for extended periods. Existing paint systems may deteriorate around irregular valve bodies, flange connections, bolts and pipe transitions. The project required a conformable cold-applied system that could be shaped around complex components and applied during maintenance work.
System used
Cold-applied protection system
- Petrolatum Primer
- Profiling / Sealing Mastic
- Petrolatum Tape
Installation process
Recorded application sequence
- Remove loose rust, dirt and surface contamination.
- Apply petrolatum primer to the prepared surface.
- Fill recesses and form smooth transitions around valves, flanges and bolts using profiling or sealing mastic.
- Wrap petrolatum tape from the adjacent straight pipe sections toward the valve body.
- Maintain approximately 50% overlap where confirmed by the project source.
- Smooth and compact overlaps and interfaces to reduce voids.
Site records
Before, during and after documentation by city
Each location is presented as a separate project record to preserve the source context of its photographs.
Project site
Nanjing China Gas
Nanjing, Jiangsu, China
Project documentation from an underground valve chamber in Nanjing records standing-water exposure, system application and the protected valve assembly.
Before
During
After
Project site
Hangzhou China Gas
Hangzhou, Zhejiang, China
Project documentation from Hangzhou shows corrosion around a valve and flange assembly, the wrapping stage and the protected component after application.
Before
During
After
Project site
Yangzhong China Gas
Yangzhong, Jiangsu, China
Project documentation from Yangzhong records a corroded valve assembly, system installation and the protected configuration after application.
Before
During
After
Technical inquiry
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