Survival of valve seals

摘要

Gobind Khiani, M.Eng., P.Eng., Fellow - Piping/Pipelines, Canada, details the requirements for sealing valves to cope with Arctic extremes. The challenges for pipelines and valves used in Arctic regions and Northern Canadian territories are the unique environmental conditions, ice scour, permafrost thaw and/or frost heave, leak detection, and containment and installation techniques. For offshore applications, pipe-in-pipe systems, non-bonded flexible pipes, composite wrapped pipes and hybrid pipes - each alternative offers strengths and weaknesses, depending on the specific hazards or failure event consequences that may exist at the location. For buried onshore pipeline, the key design issue is the potential for high bending strains resulting from frost heave and thaw settlement.