TABLE OF CONTENTS The choice of pressure versus atmospheric vessel for the skimmer tank is not determined solely by the water treating requirements. The overall needs of the system must be considered in this decision. Pressure vessels are more expensive than tanks. However, they are recommended where
Potential gas blow-by through the upstream vessel dump system could create too much back-pressure in an atmospheric vent system.
The water must be dumped to a higher level for further treating and a pump would be needed if an atmospheric vessel were installed.
Due to the potential danger from overpressure and potential gas venting problems associated with atmospheric vessels, pressure vessels are preferred downstream of pressurized three-phase separators. However, an individual cost/benefit decision must be made for each application, taking into account all the requirements of the system.
