When you're shopping for industrial valves, choosing the right ball valve means balancing port size, body material, pressure rating, and what the valve will actually be connecting to. The two valves on the table are aimed at threaded pipework, but they take slightly different paths: one is a 1-inch 316 stainless steel full-port ball valve sold as a two-pack, and the other is an FNW Fig 321A 3/4-inch carbon steel ball valve with a 3-piece body. The choice comes down to your pipe size, pressure needs, and how much you want to spend.
Quick Verdict
If you need a 1-inch service line for water, oil, or gas and want a corrosion-resistant full-port valve, the 1-inch 316 stainless steel two-pack is the straightforward choice. If your connection is 3/4-inch female threaded pipe and you prefer a 3-piece body design, the FNW Fig 321A is the better fit.
At a Glance
| Feature | 1 in. 316 SS Full-Port Ball Valve (2-Pack) | FNW Fig 321A 3/4 in. Carbon Steel Ball Valve |
| Listed price | USD 16.59 | USD 39.00 |
| Connection size | 1 in. | 3/4 in. |
| Body material | 316 stainless steel | Carbon steel |
| Pressure marking | 1000 WOG | 150 WSP |
| End connection | NPT threaded | FPT |
| Body design | 2-piece | 3-piece |
| Included | 2 valves | 1 valve |
Where Each Product Wins
Where the 1-Inch 316 SS Two-Pack Wins
- The 316 stainless steel body gives you corrosion resistance for water, oil, and gas service.
- The full-port bore helps keep flow restriction lower than a smaller valve.
- The PTFE seals are built in, and the listed temperature range runs from -60°F to 450°F.
- The package includes two valves, giving you a spare or a second station for the same purchase.
Where the FNW Fig 321A Wins
- The FPT end connections fit smaller threaded lines that won't accept a larger valve.
- The 3-piece body design gives you a different construction layout than the 2-piece valve.
- The carbon steel housing is a distinct material choice for the same type of service.
- The Fig 321A model number makes the valve easy to identify and match to your application.
Product Notes
1-Inch 316 Stainless Steel Full-Port Ball Valve (2-Pack)
The one-inch stainless steel ball valve gives you two full-port valves for USD 16.59, which makes it the lower-priced way to cover a one-inch threaded water, oil, or gas line. The 316 stainless steel body is a strong match for corrosion-resistant service, and the PTFE seals are included to help protect the internal components over the valve's lifespan. With a 1000 WOG pressure marking, it is rated for service up to 1000 psi for water, oil, and gas, and the listed temperature range of -60°F to 450°F gives you a wide working window. The limitation is the size: at one inch, it won't drop into a 3/4-inch line without changing the piping, and if you need a 3-piece body for a particular maintenance setup, this is a 2-piece valve.
FNW Fig 321A 3/4-Inch Carbon Steel 3-Piece Ball Valve
The FNW Fig 321A is a 3/4-inch carbon steel ball valve with a 150 WSP pressure marking and FPT end connections, and its listed price is USD 39.00. The 3-piece body design is the main difference from the two-piece stainless valve, and the smaller 3/4-inch size makes it the right choice when your threaded line can't accept a one-inch valve. Carbon steel is a different body material than stainless, so you are choosing a different corrosion profile for the service. The limitation is that you get one valve for more than twice the money, and the pressure marking is 150 WSP rather than 1000 WOG, so it is not the high-pressure water/oil/gas choice even though it costs more.
Final Choice by Use Case
Choose the stainless steel two-pack when you want the corrosion resistance of 316 stainless steel, a full-port design, and a second valve as a spare. Choose the FNW Fig 321A when the 3-piece carbon steel construction and FPT connections line up with the service you need.
