Cast Pipe Fittings Union 1-1/2ft NPT Female Stainless Steel 304

In this review the Cast Pipe Fittings Union 1-1/2' NPT Female is evaluated for plumbers, workshop fabricators, and maintenance technicians who need a reliable threaded union that resists corrosion and survives repeated assembly. The bottom line: this union is a workmanlike, no-nonsense connector built from stainless steel 304 that replaces weaker brass parts and handles a wide range of temperatures and pressures, making it a solid choice when longevity and cross-material compatibility matter.

Key Features

• Size and fit: The 1-1/2' NPT female thread provides a standard threaded connection for joining two male pipes without welding, saving time on installation.
• Material: Constructed from stainless steel 304 to resist corrosion and offer greater durability than brass in demanding environments.
• Union design: The coupling shape allows easy disassembly and reconnection for maintenance or system reconfiguration.
• Temperature range: Rated from -29 to 120C so it can be used in cold storage lines and many hot water or process applications.
• Pressure capability: Class 150 rating up to 360 PSI working pressure for common industrial and plumbing duties.
• Material compatibility: Can be joined to copper, brass, plastic, aluminum, and welded steel, which simplifies mixed-material systems.

Who It's For

This union is aimed at professional plumbers, HVAC and process technicians, and hobby fabricators who need a durable threaded coupling that tolerates repeated use and exposure to corrosive conditions. The use of stainless steel 304 makes it attractive where brass fittings have failed or when a longer service life is required.

It may be overkill for purely decorative or very low-stress DIY projects where cost is the primary concern, and those needing higher pressure or specialty alloys for acidic environments should look for a different grade of steel or a higher pressure class.

Pros & Cons

Pros

• Durable stainless steel construction that resists corrosion better than brass.
• Threaded union design permits easy assembly, disassembly, and system modification.
• Wide working temperature range suitable for many industrial and plumbing systems.
• Compatible with multiple pipe materials, simplifying repairs and retrofits.

Cons

• Class 150 pressure rating may not suit very high-pressure industrial systems requiring higher classes.
• Stainless steel parts can cost more than basic brass alternatives for low-demand uses.

Specifications

Type	Threaded Union (coupling)
Size	1-1/2' NPT Female
Material	Stainless Steel 304
Pressure Rating	Class 150 (0-360 PSI working)
Working Temperature	-29 to 120C (-20 to 245F)
Compatibility	Copper, brass, plastic, aluminum, welded steel

Our Verdict

The Cast Pipe Fittings Union 1-1/2' NPT Female is a reliable, value-minded choice for professionals who need a durable threaded connector that tolerates mixed materials and routine maintenance. Its stainless steel 304 construction and practical pressure and temperature ratings make it a sensible upgrade over brass for most plumbing and light industrial tasks.

Frequently Asked Questions

Is this union compatible with copper pipe?
Yes. The stainless steel 304 union can be connected to copper, as well as brass, plastic, aluminum, and welded steel.

What is the maximum working pressure?
The union is rated as Class 150 with a working pressure up to 360 PSI as specified.

What temperature range can it handle?
It is rated for working temperatures from -29C to 120C (-20F to 245F).