A large oil/gas refinery located in the Southern US along a major river utilizes water from the river for process cooling in its operations. A large amount of water is used in the refining process by the plant that must be treated after use in the plant and then returned to the river. An accurate and low maintenance flow monitoring system is essential to keep water intake, treatment and return operational costs as low as possible.
The US EPA requires that the plant must monitor all raw water intake from the river and treated water outflow back into the river from the plant for pollution monitoring purposes. Inflow is metered just after the water passes through the cooling system, while outflow is measured as treated refinery wastewater prior to re-entering the river. Accurate measurement ensures the plant meets all water quality regulations to avoid audit problems and potential fines.
The refinery initially relied on spool-piece electromagnetic flow meters, but their high maintenance requirements necessitated the frequent shut down of the water line to remove the meter for cleaning and component replacement, which incurred significant maintenance crew, maintenance equipment and spare part costs.