Parker 68CA-3-4 Brass Compression Tube Connector

Product Description

The PARKER 68CA-3-4 is a brass compression tube connector designed to join 3/16 inch outside diameter tubing to a male NPTF threaded port. It uses a compression fitting on one end and a 1/4-18 MNPT connection on the other, creating a reliable mechanical seal without soldering or flaring. Rated to 1900 psi maximum working pressure and suitable for temperatures from -65 degrees F to 250 degrees F, this connector is built for demanding fluid and pneumatic line applications. Plumbers, HVAC technicians, and instrumentation installers use this type of fitting where tube-to-pipe transitions are required in tight or permanent installations.

This connector is well suited for residential and light commercial plumbing, HVAC refrigerant or pneumatic control lines, and hydraulic instrument tubing runs. The compression-by-MNPT configuration is common when connecting small-diameter copper or steel tubing to threaded valve bodies, manifolds, or equipment ports. The brass construction resists corrosion and holds up in both wet and dry service environments. It is sold individually and is appropriate for new installations and service replacements alike.

Key Features

• Compression x MNPT end connections for tube-to-pipe transitions without soldering
• 3/16 inch tube outside diameter compatibility
• 1/4-18 NPTF thread standard for positive pressure seal
• 1900 psi maximum working pressure for high-demand service
• Operating temperature range of -65 degrees F to 250 degrees F
• Brass construction for corrosion resistance in plumbing and HVAC applications

Compatibility

Designed as an OEM-style replacement or new-installation fitting for systems using 3/16 inch OD tubing with 1/4-18 NPTF threaded ports in plumbing, HVAC, and fluid instrumentation applications.

Installation Notes

Installation should be performed by a licensed plumber or qualified HVAC or instrumentation technician. Shut off all fluid or pneumatic supply and relieve system pressure before removing or installing compression fittings. Hand-tighten the compression nut onto the tube, then advance with a wrench per standard compression fitting practice — do not overtighten, as this can deform the ferrule and compromise the seal. Verify thread engagement meets NPTF standards and confirm all connections are leak-free before returning the system to service.