Graco 127339 Valve Check 1/8" MNPT X FNPT

Graco 127339 Check Valve – 1/8″ MNPT × 1/8″ FNPT

The Graco 127339 check valve is a compact one-way fluid valve designed to maintain directional flow in Graco systems by preventing backflow. Its 1/8″ MNPT to 1/8″ FNPT ports make it ideal for high-precision fluid control applications.

Compatible Graco Machines

This check valve is commonly found in Graco fluid systems and proportioning machines. Typical compatible models include:

• Graco ProMix 2KS Series Proportioners
• Graco Xtreme Mix Proportioners
• Graco Plural-Component Proportioners (2-component systems)
• Graco Metering and Dispensing Systems with small-port check valves

*Compatibility varies by system configuration—refer to your machine’s parts manual to verify.

Key Features

• 1/8″ MNPT (male) to 1/8″ FNPT (female) connections
• Prevents reverse flow in fluid circuits
• Compact and lightweight design
• Genuine Graco OEM part ensures reliability and performance
• Ideal for metering, proportioning, and precision dispensing systems

Technical Specifications

Why Use This Check Valve?

Installing the Graco 127339 ensures consistent, one-directional fluid flow, which protects your system from pressure spikes, backflow, and contamination. It’s a vital component for maintaining precision in plural-component and metering equipment.

Installation & Maintenance Tips

• Ensure the valve is installed in the correct orientation — observe the flow arrow (if present).
• Apply a small amount of thread sealant to NPT threads, but avoid contaminating the valve seat.
• Periodically inspect for debris or build-up inside the valve.
• If blocked or leaking, replace with a genuine Graco check valve to maintain system integrity.

Safety Notes

Always depressurize the fluid system before installing or servicing the check valve. Improper installation can lead to leaks, reversed flow, or component failure.

Frequently Asked Questions