What is an oscillating piston meter?

Neptune Type MP oscillating piston meters use a precision-machined chamber containing a cylindrical piston that oscillates as liquid flows. The piston's central shaft is constrained to run in a circular groove in the chamber, resulting in an off-center rotating motion as the liquid sequentially enters and exits compartments machined into the underside of the piston. Since the volume of the compartments are known, the amount of liquid metered per revolution can be calculated accurately.

Advantages of Neptune oscillating piston meters:

• Only two moving parts
• Hydraulically floating piston does not contact the chamber surfaces during operation
• Easily serviceable because its simple construction requires no special knowledge or tools
• Dual case design
• Measuring element is replaceable and doesn't require the meter to be removed from line
• Tolerant of low viscosity, abrasive, non-lubricating compressed gas
• Nituff coating reduces friction and protects from particulate damage
• Components undergo strengthening treatment to increase durability
• Works with mechanical and electronic registers
• Tested under field conditions to optimize design