Exploring the Application Potential of Forged 2-inch A182 F22 150lb RF Thread Pipe Flange

A forged 2-inch A182 F22 150 lb raised-face (RF) threaded pipe flange is a compact, strong fitting for lines that must not be welded: it screws onto a matching threaded pipe. The chrome-molybdenum alloy resists heat and hydrogen, and the raised face seats the gasket. See our flange products and flange gaskets.

What the F22 Threaded Flange Is

A182 F22 is a 1.25% chromium, 0.5% molybdenum alloy steel made for service that sees heat, hydrogen, or both. A threaded (NPT) flange carries internal pipe thread instead of a weld bevel, so it joins a threaded pipe end by screwing on. The 150 lb (Class 150) rating sets the pressure-temperature limit, and the raised face gives the gasket a defined sealing band.

Material and Form

• A182 F22 forged body — chrome-molybdenum alloy for heat and hydrogen resistance.
• Threaded (NPT) bore — screws onto a matching pipe, no welding needed.
• 150 lb (Class 150) rating — sets the allowable pressure at a given temperature.
• Raised face (RF) — a concentric raised ring that centers and compresses the gasket.

Why 2-Inch and 150 lb

At 2-inch size the threaded joint is still easy to make up by hand or with chain tongs, and Class 150 covers most utility and low-pressure process lines. For higher pressure move to a weld neck or socket-weld flange in a heavier rating; the threaded form is chosen where welding is unsafe or impractical.

Why Choose F22 and Threaded

F22 keeps strength at elevated temperature better than plain carbon steel and resists hydrogen attack in refinery and heater services. Threaded flanges suit lines that cannot be welded on site — temporary skids, hazardous areas, or small-bore branches where a weld would be costly. The pair is a practical answer for low-pressure, hot, or sour-adjacent runs.

Key Benefits

• Heat and hydrogen resistance from the Cr-Mo alloy in F22.
• No welding — faster, safer tie-in on live or hazardous lines.
• Compact 2-inch size, easy to make up and break out for maintenance.
• Raised face gives a repeatable gasket seal within the Class 150 limit.

Where They Are Used

These flanges sit on low-pressure utility headers, instrument and sampling branches, cooling water and fire-water lines, and small process take-offs in refineries, power plants, and chemical units. They fit any place a reliable, non-welded joint is wanted within Class 150.

In the Joint

The gasket between the faces seals the line while the flange body carries the thread and the bolts pull the pair together. Because the joint is threaded, keep thread sealant in spec and do not rely on the thread for the pressure boundary alone.

Installation and Care

Cut the pipe square, clean the threads, and apply an approved thread sealant before screwing the flange home — use a strap wrench, not a pipe wrench on the flange, to avoid scoring the raised face. Torque the bolts evenly in a cross pattern to seat the gasket without twisting the joint. Inspect at turnaround for thread leakage and face damage; threaded joints weep under thermal cycling, so re-torque if the line sees wide temperature swings.

Frequently Asked Questions

F22 or F304 for a hot line?

For sustained heat or hydrogen service pick F22 (Cr-Mo). For general corrosion resistance at moderate temperature, 304 stainless is the simpler choice.

Can a 150 lb threaded flange take high pressure?

No — the Class 150 rating caps the working pressure; above it use a heavier rating and a weld-type flange. Threaded forms are for low-pressure lines.

Threaded or socket-weld for vibration?

For vibrating small-bore lines a socket-weld or a union is steadier; a threaded flange can loosen under cyclic movement, so add thread lock and re-torque.