Rotork’s innovative CVA electric control valve actuators can assist the natural gas industry to eliminate the problem of freezing in pipelines and equipment.
Gas hydrate formation is a potentially serious problem in natural gas flow lines in every area, from the production well through to customer delivery. Depending on operating and ambient conditions, water molecules in natural gas may freeze and form gas hydrates which can block pipelines and equipment. The effective inhibition of hydrate formation, especially in cold weather, is therefore essential for the producers and transmission companies in order to maintain a continuous gas supply.
The problem can be alleviated by methanol injection in a process that can prove to be more efficient and simpler than the traditional practice of glycol dehydration, as well as eliminating the emission of methane and volatile organic compounds (VOCs).
The use of Rotork CVA electric control valve actuators removes the requirement for an instrument air supply for the methanol injection process, reducing capital, running and maintenance costs. In addition, the all-electric solution can enable installations to run on renewable power supplies, reducing energy costs to negligible levels.
CVA actuators deliver continuous, repeatable modulating control with a programmable fail to position option. Resolution, repeatability and hysteresis performance is quoted at less than 0.1% of full scale, offering suitability for the most demanding control valve applications. A rugged, double-sealed IP68 watertight and explosionproof enclosure enhances long term maintenance-free reliability in the harshest of environments.