Midland Industries SS5406-C-06 Hex Pipe Cap 3/8 in Nptf

Product Description

The MIDLAND INDUSTRIES SS5406-C-06 is a hex pipe cap machined from 316 stainless steel, designed to seal a 3/8-inch female NPTF port in hydraulic, pneumatic, or fluid-system piping. Rated to 5300 psi and suitable for service up to 1000 degrees F, this cap handles demanding industrial and process environments where corrosion resistance and pressure integrity are critical. The 3/8-18 thread pitch matches standard NPTF taper requirements, creating a pressure-tight mechanical seal without sealant tape on properly gauged ports. At 0.811 inches in length with a 7/8-inch hex, it is a compact fitting that seats flush and is easy to torque with standard wrenches.

This hex pipe cap is used to plug or pressure-test 3/8-inch NPTF female ports on manifolds, valve bodies, pumps, compressors, and instrumentation fittings in industrial, HVAC, plumbing, and process-control installations. It is a common service fitting for temporarily or permanently blocking unused ports during system commissioning or modification. Plumbers, pipefitters, and industrial maintenance technicians routinely specify this cap wherever a stainless, high-pressure port closure is required.

Key Features

• 316 stainless steel construction provides excellent corrosion resistance in wet, chemical, and high-temperature environments
• Rated to 5300 psi for use in high-pressure hydraulic and pneumatic systems
• Rated for service up to 1000 degrees F, suitable for steam and high-heat process lines
• 3/8-18 NPTF taper thread delivers a pressure-tight seal on conforming female ports
• 7/8-inch hex allows installation and removal with standard open-end or combination wrenches
• Compact 0.811-inch length minimizes protrusion on crowded manifolds and valve bodies

Compatibility

Designed as an OEM-style replacement or new-installation pipe cap for 3/8-inch female NPTF ports on industrial piping, manifolds, and fluid-handling equipment requiring a 316 stainless steel closure fitting.

Installation Notes

Installation should be performed by a qualified pipefitter or plumber following applicable IPC or ASME B31 piping codes. Always depressurize and de-energize the system fully before removing or installing any pipe fitting. Inspect the female NPTF port for damage or contamination before threading the cap in by hand, then tighten with a wrench to achieve a leak-free seal. Do not over-torque, as stainless steel threads can gall; applying an appropriate anti-seize compound approved for the service fluid is recommended.