Carbon Steel and Stainless Steel Flanges for Pipe Connections - Quality Products from China Suppliers and Factory
Common Flange Types
| Flange Type | Description | Typical Applications |
| Weld Neck Flange (WN) | Features a long tapered hub that provides reinforcement; butt-welded to pipe | High-pressure, high-temperature services; critical applications requiring high integrity |
| Slip-On Flange (SO) | Slides over pipe and welded both inside and outside; lower installation cost | Low to medium pressure applications; general piping systems |
| Blind Flange (BL) | Solid flange with no bore; used to close pipe ends, valves, or pressure vessel openings | Pipeline termination; pressure testing; future expansion points |
| Threaded Flange (THDF) | Bore with threads; screws onto threaded pipe without welding | Low-pressure utility services; areas where welding is hazardous |
| Socket Weld Flange (SW) | Bore with socket counterbore; pipe inserted and fillet welded | Small diameter, high-pressure lines; typically ½" to 4" NPS |
| Lap Joint Flange (LJ) | Two-part assembly with stub end and backing flange; flange rotates freely | Systems requiring frequent dismantling; corrosive services with expensive materials |
Flange Facing Types
| Face Type | Description | Typical Gasket |
| Raised Face (RF) | Sealing surface raised above bolt circle; most common facing | Soft or semi-metallic gaskets |
| Flat Face (FF) | Sealing surface flush with bolt circle | Full-face non-metallic gaskets |
| Ring-Type Joint (RTJ) | Groove machined into face for metal ring gasket | Oval or octagonal metal ring gaskets |
Standard
| Material Type | Standard | Common Grades |
| Carbon Steel | ASTM A105 | Standard specification for forged carbon steel piping components |
| Carbon Steel (Low Temp) | ASTM A350 | For low-temperature service; common grade LF2 |
| Stainless Steel | ASTM A182 | Forged stainless steel; common grades F304, F304L, F316, F316L |
| Alloy Steel | ASTM A182 | Chrome-moly grades for high-temperature; F11, F22 |
Wall Thickness Schedules
Frequently Asked Questions
What are the most common types of industrial flanges?
The most widely used types include Weld Neck (WN), Slip-On (SO), Blind (BL), Threaded (THDF), Socket Weld (SW), and Lap Joint (LJ) flanges, each serving specific pressure and piping needs.
When should I use a Weld Neck Flange versus a Slip-On Flange?
Weld Neck flanges are preferred for high-pressure and extreme temperature applications due to their reinforced hub. Slip-On flanges are more cost-effective for low-to-medium pressure general piping systems.
What is the purpose of a Blind Flange?
A Blind Flange is used to seal the end of a piping system or a pressure vessel opening. It is commonly used for isolating a pipe section or for future expansion points.
What material standards apply to stainless steel flanges?
ASTM A182 is the primary standard for forged stainless steel flanges, covering popular grades such as F304, F304L, F316, and F316L.
Which flange facing is best for high-pressure sealing?
Ring-Type Joint (RTJ) facings are specifically designed for high-pressure and high-temperature environments, utilizing a metal ring gasket that fits into a machined groove.
Can threaded flanges be used in high-pressure systems?
Generally, threaded flanges are limited to low-pressure utility services and are ideal for areas where welding is not permitted or is hazardous.