Parker CV-1-1188 Inline Check Valve 1/2 Inch Fnpt

Product Description

The PARKER CV-1-1188 is an inline check valve designed to allow one-directional flow while preventing backflow in fluid and gas piping systems. The body and spring are constructed entirely of polytetrafluoroethylene (PTFE), making this valve well suited for chemically aggressive media where metal-bodied valves would corrode or contaminate the process stream. Connections are 1/2 inch FNPT on both ends, and the valve carries a Cv rating of 4.220, indicating relatively low flow restriction for its pipe size. Crack pressure ranges from 0.25 to 0.75 psi, allowing the valve to open under minimal differential pressure. Licensed plumbers, pipefitters, and industrial maintenance technicians are the primary installers.

This check valve is appropriate for residential and light commercial plumbing, chemical feed lines, water treatment systems, and process piping where PTFE chemical resistance is required. The FNPT x FNPT end connections allow direct threaded installation into standard 1/2 inch NPT piping. Operating temperature is rated up to 130 degrees F, and the lower limit is -32 degrees C (approximately -26 degrees F), covering a broad range of ambient and fluid temperatures common in indoor mechanical and process applications. Its all-PTFE construction makes it a common choice where contact with chlorinated water, mild acids, or other corrosive fluids is expected.

Key Features

• All-PTFE body and spring construction for broad chemical resistance
• 1/2 inch FNPT x FNPT threaded end connections for straightforward in-line installation
• Low crack pressure (0.25 to 0.75 psi) allows opening under minimal differential
• Cv rating of 4.220 minimizes pressure drop across the valve at normal flow rates
• Rated to 130 degrees F maximum, suitable for cold and ambient-temperature fluid service
• Inline valve orientation keeps installation compact within existing pipe runs

Compatibility

Designed as an OEM-style replacement or new-installation inline check valve for 1/2 inch NPT threaded piping systems requiring PTFE wetted components.

Installation Notes

Installation is performed by a licensed plumber or qualified pipefitter in accordance with applicable plumbing codes such as the IPC. Shut off system pressure and depressurize the line completely before removing any existing valve or fitting. Apply thread sealant rated for PTFE-compatible service; avoid over-tightening threaded PTFE-bodied fittings, as excessive torque can crack the body. Verify flow-direction orientation before final make-up, as check valves are directional and will not function if installed backwards.