Firstco CP81-51 Orifice Piston 0.051 Inch Fixed Metering Device

The Firstco CP81-51 is a fixed orifice piston designed for use in residential heat pump and air conditioning systems. This precision-manufactured metering device features a 0.051-inch bore diameter, making it suitable for systems requiring precise refrigerant flow control.

Key Features:

• 0.051-inch (51 thousandths) orifice diameter for accurate refrigerant metering
• Fixed orifice design provides reliable, consistent performance
• Genuine OEM Firstco replacement part ensures proper fit and compatibility
• Brass construction for durability and corrosion resistance
• Designed for heat pump applications with bi-directional flow capability

Orifice pistons are essential components in HVAC refrigerant circuits, creating the necessary pressure drop between the liquid line and evaporator coil. The fixed bore design meters a steady flow of high-pressure liquid refrigerant into the evaporator, where it absorbs heat and evaporates. In heat pump systems, the piston slides within its housing to allow restricted flow in one direction (metering) and unrestricted flow in the opposite direction (bypass mode). The correct piston size is critical for proper system superheat and efficient operation.

This replacement piston is sized according to manufacturer specifications and should be installed following the equipment manufacturer's guidelines for optimal system performance.