Parker 398PDSS-4-4 Double End Shutoff Pipe Coupler

Product Description

The PARKER 398PDSS-4-4 is a double end shutoff pipe coupler designed for inline fluid control in compressed air, gas, and liquid plumbing systems. It connects via compression fitting on one end and male NPT (MNPT) on the other, allowing a tool-free tube connection to a threaded port. Constructed from 316 stainless steel, this coupler resists corrosion in harsh or chemically aggressive environments. It carries a maximum working pressure of 150 psi, making it suitable for low-to-medium pressure service lines. The double end shutoff design allows flow to be blocked at both ends when disconnected, reducing fluid loss during maintenance. Licensed plumbers, pipefitters, and industrial maintenance technicians are the typical installers.

This coupler is well suited for residential and commercial plumbing, pneumatic tool lines, process instrumentation, and light industrial fluid systems where a stainless steel compression-to-threaded transition is required. The 1/4-18 NPT thread size is a common standard for instrument and utility connections. The compression end accommodates tubing without requiring solder, flare, or adhesive, making it a practical choice for field installations where tube cutting and hand tools are the primary resources.

Key Features

• Double end shutoff design blocks flow at both ends when disconnected, minimizing fluid loss during service
• 316 stainless steel construction for superior corrosion resistance in wet, chemical, or outdoor environments
• Compression x MNPT end connections for a reliable tube-to-threaded-port transition
• 1/4-18 NPT thread size suits common instrument and utility line fittings
• 150 psi maximum working pressure rated for low-to-medium pressure service
• Sold as a single unit with no minimum order quantity greater than one

Compatibility

Designed as an OEM-style replacement or new-installation fitting for compression tube systems requiring a double end shutoff coupler with a 1/4-18 MNPT threaded port connection in stainless steel construction.

Installation Notes

Installation should be performed by a licensed plumber or qualified pipefitter in accordance with applicable IPC or IFGC standards for the fluid or gas being conveyed. Depressurize and isolate the line completely before removing any existing fitting or installing this coupler. Ensure the compression tube end is cut cleanly and squarely, and that the tube is fully seated before tightening the compression nut. Do not overtighten the NPT threads; apply an appropriate thread sealant rated for the service fluid.