Neptune 4D-MT LPG Tank Truck Meter

The Neptune 2″ LPG meter is the worldwide standard for truck mounted metering. The aluminum body flowmeter comes complete and ready for installation. The 2″ Type 4D-MT meter for Liquefied Propane Gas features a flanged outlet with ductile iron companion flange for easy installation and removal. The 2″ Type 4D-MT is 33% lighter in weight than the old 2″ Type 4D.

The standard 4D-MT meter comes with:

  • Strainer
  • Vapor release
  • Pressure relief
  • Inlet Check valve
  • Differential valve
  • Vent-line check valve
  • Thermometer well

Available with Automatic Temperature Compensator (ATC) that compensates to 15° Celsius.

The dependable and accurate Neptune oscillating piston design has long been the meter of choice for refined fuel delivery. The straightforward operating principle requires few moving parts and results in a robust and durable mechanism. Combined with the E4000 electronic register, the Neptune LP gas meter delivers the highest accuracy and reliability attainable in mechanical metering.


  • The industry standard for truck mounted custody transfer and invoicing
  • Oscillating piston with hard, low-friction Nituff Teflon – impregnated coating for long life
  • Registration flexibility – fully compatible with Neptune mechanical registers and the Neptune E4000 Electronic Register
  • Weights and Measures approved worldwide
  • Easy installation
  • Easily repairable. If necessary, the measuring chamber can be replaced in line with simple tools.


O&M Manual
Tech Sheet
Parts List