A Stainless Steel Socket Weld Flange is a type of ASME B16.5 flange designed for small-diameter, high-pressure piping systems. The common material standards and grades for stainless steel are ASTM A182 Grade F304/L and F316/L, with pressure ratings ranging from Class 150 to Class 2500. Stainless steel is utilized in more industries than carbon steel because it offers superior corrosion resistance and an aesthetically pleasing appearance.
What is socket weld flange?
A Socket Weld Flange (SW Flange) is a type of ASME B16.5 flange designed for small-diameter and high-pressure piping systems. It features a socket (recessed bore) where the pipe is inserted before being fillet welded on the outside.
Key Features of Socket Weld Flanges
High Strength – Provides a strong, leak-proof connection.
Smooth Flow – The bore matches the pipe’s inner diameter, reducing flow restrictions.
Small Pipe Applications – Used for pipes 2 inches (DN50) or smaller.
Socket Weld Flange Structure
Recessed Area (Socket) – The pipe is inserted into this area for precise alignment.
Fillet Weld Groove – A fillet weld is applied on the outer side of the pipe.
Smooth Bore – Internal diameter matches the pipe to minimize flow restrictions.
What is a stainless steel flange?
A stainless steel flange is a type of pipe flange made from stainless steel, designed to connect pipes, valves, pumps, and other equipment in a piping system. It provides a strong, corrosion-resistant, and durable connection, making it ideal for industries such as oil & gas, chemical processing, water treatment, and marine applications.
Key Features of Stainless Steel Flanges
Corrosion Resistance – Highly resistant to rust, oxidation, and chemical corrosion.
High Strength & Durability – Can withstand high pressure and temperature.
Versatile Applications – Suitable for industrial, food-grade, and marine environments.
Recyclable & Sustainable – Environmentally friendly and long-lasting.
Specification of ASME 16.5 Socket Weld Flange
| Size Range | 1/2″- 3″ / DN15 – DN80 |
| Pressure Rating | Class 150, 300, 600, 1500 |
| Standard | ANSI / ASME B16.5 |
| Stainless Steel | ASTM A182 F304 / 304L / 304H, 316 / 316L, 310S, 317, 347, 904L |
| Duplex Stainless Steel | ASTM A182 F51, F53, F44 |
Stainless Steel Flange Chemical Composition
| CHEMICAL | LIMITS | C | Mn | P | S | Si | Ni | Cr | Mo | N |
| ASTM A182 F304 | MIN | 8.0 | 18.0 | |||||||
| MAX | 0.08 | 2.00 | 0.045 | 0.030 | 1.00 | 11.0 | 20.0 | 0.10 | ||
| ASTM A182 F316 | MIN | 10.0 | 16.0 | 2.00 | ||||||
| MAX | 0.08 | 2.00 | 0.045 | 0.030 | 1.00 | 14.0 | 18.0 | 3.00 | 0.01 |
Stainless Steel Flange Mechanical Property
| MATERIAL | ASTM A182 F304 | ASTM A182 F316 |
| T.S (MPA) | 515 min | 515 min |
| Y.S (MPA) | 205 min | 205 min |
| EL % | 30 min | 30 min |
| R/A % | 50 min | 50 min |
What type of flange is ASME?
ASME (American Society of Mechanical Engineers) flanges are industrial flanges manufactured according to ASME standards, primarily ASME B16.5 and ASME B16.47. These standards specify the dimensions, materials, pressure ratings, and design of flanges used in piping systems for various industries like oil & gas, chemical processing, and power plants.
1. Weld Neck Flange (WN)
Has a long tapered hub for high-stress applications.
Provides excellent strength and leak-proof connections.
Used in high-pressure, high-temperature applications.
2. Slip-On Flange (SO)
Easier to install than weld neck flanges.
Requires fillet welding on both the inside and outside.
Suitable for low-pressure, low-temperature applications.
3. Blind Flange (BL)
Solid flange used to close off pipelines, valves, or pressure vessels.
Withstands high pressure and stress conditions.
Used in testing and maintenance of pipeline systems.
4. Socket Weld Flange (SW)
Pipe is inserted into the flange and fillet-welded at the connection.
Good for small-diameter, high-pressure piping.
Reduces turbulence and improves flow efficiency.
5. Threaded Flange (TH)
Has internal threads, allowing pipes to be screwed in.
No welding is required, making installation easier.
Used in low-pressure, flammable, and hazardous environments.
6. Lap Joint Flange (LJ)
Used with a stub end for easy pipe alignment.
Suitable for frequent disassembly and maintenance.
Often used in low-pressure, non-critical applications.
7. Ring-Type Joint Flange (RTJ)
Has a groove for a metal ring gasket, providing a leak-proof seal.
Ideal for high-pressure, high-temperature environments.
Common in oil & gas, petrochemical, and offshore applications.
ASME Flange Standards & Pressure Ratings
ASME B16.5 – Flanges up to 24 inches (150# to 2500# pressure class).
ASME B16.47 – Large-diameter flanges (Series A & B) above 24 inches.
ASME B16.48 – Covers line blank flanges (paddle & spectacle blinds).
Socket Weld Flange Dimensions
Class 150 lb Socket Weld Flange
| NPS | A | B | C | D | E | K | F | G | H | I | J | W |
| inch | No. of Holes | inch | kg/pc | |||||||||
| mm | mm | |||||||||||
| 1/2 | 3.5 | 0.62 | 0.44 | 0.62 | 0.88 | 0.38 | 1.19 | 1.38 | 4 | 0.62 | 2.38 | 0.42 |
| 88.9 | 15.7 | 11.2 | 15.7 | 22.4 | 9.6 | 30.2 | 35.1 | 15.7 | 60.45 | |||
| 3/4 | 3.88 | 0.82 | 0.5 | 0.62 | 1.09 | 0.44 | 1.5 | 1.69 | 4 | 0.62 | 2.75 | 0.59 |
| 98.6 | 20.8 | 12.7 | 15.7 | 27.7 | 11.1 | 38.1 | 42.9 | 15.7 | 69.85 | |||
| 1 | 4.25 | 1.05 | 0.56 | 0.69 | 1.36 | 0.50 | 1.94 | 2.0 | 4 | 0.62 | 3.120 | 0.81 |
| 108 | 26.7 | 14.2 | 17.5 | 34.5 | 12.70 | 49.3 | 50.8 | 15.7 | 79.25 | |||
| 1-1/4 | 4.62 | 1.38 | 0.62 | 0.81 | 1.7 | 0.56 | 2.31 | 2.5 | 4 | 0.62 | 3.5 | 1.07 |
| 117.3 | 35.1 | 15.7 | 20.6 | 43.2 | 14.2 | 58.7 | 63.5 | 15.7 | 88.9 | |||
| 1-1/2 | 5.0 | 1.61 | 0.69 | 0.88 | 1.95 | 0.62 | 2.56 | 2.88 | 4 | 0.62 | 3.88 | 1.36 |
| 127 | 40.9 | 17.5 | 22.3 | 49.5 | 15.7 | 65.0 | 73.15 | 15.7 | 98.6 | |||
| 2 | 6.0 | 2.07 | 0.75 | 1.0 | 2.44 | 0.69 | 3.06 | 3.62 | 4 | 0.75 | 4.75 | 2.10 |
| 152.4 | 52.6 | 19.1 | 25.4 | 62.0 | 17.5 | 77.7 | 91.9 | 19.1 | 120.7 | |||
| 2-1/2 | 7.0 | 2.47 | 0.88 | 1.12 | 2.94 | 0.75 | 3.56 | 4.12 | 4 | 0.75 | 5.5 | 3.33 |
| 177.8 | 62.7 | 22.4 | 28.4 | 74.7 | 19.0 | 90.4 | 104.6 | 19.1 | 139.7 | |||
| 3 | 7.5 | 3.07 | 0.94 | 1.19 | 3.57 | 0.81 | 4.25 | 5.0 | 4 | 0.75 | 6.0 | 3.90 |
| 190.5 | 78.0 | 23.9 | 30.2 | 90.7 | 20.6 | 108. | 127 | 19.1 | 152.4 | |||
What is the difference between socket weld flange and weld neck flange?
Socket Weld Flanges (SW Flange) and Weld Neck Flanges (WN Flange) are both ASME B16.5 flanges used in high-pressure applications, but they differ in design, welding method, and applications.
1. Design & Structure
| Feature | Socket Weld Flange (SW) | Weld Neck Flange (WN) |
| Neck/Hub | No extended neck; has a socket (recessed bore) to insert the pipe. | Has a long tapered hub that transitions smoothly to the pipe. |
| Welding Method | Fillet weld on the outside of the flange. | Butt weld between the pipe and flange neck. |
| Pipe Fitment | The pipe is inserted into the socket before welding. | The pipe is butt-welded to the flange hub for a seamless connection. |
2. Strength & Pressure Handling
| Factor | Socket Weld Flange (SW) | Weld Neck Flange (WN) |
| Strength & Fatigue Resistance | Moderate strength, suitable for smaller pipes. | Higher strength and fatigue resistance due to the long hub. |
| Pressure Rating | Used for medium to high-pressure applications. | Suitable for high-pressure and high-temperature applications. |
| Stress Distribution | More localized stress due to fillet weld. | Even stress distribution due to smooth transition in the hub. |
3. Advantages & Disadvantages
| Feature | Socket Weld Flange (SW) | Weld Neck Flange (WN) |
| ✅ Advantages | Easier to install and requires only fillet welding. | Stronger connection with superior fatigue resistance. |
| ❌ Disadvantages | Not ideal for large pipes; risk of corrosion in crevices. | Requires more welding & preparation but offers better durability. |
Which One Should You Choose?
Choose Socket Weld Flange → If you need an easy-to-install flange for small-diameter, moderate-pressure applications.
Choose Weld Neck Flange → If you need a high-strength, durable flange for large pipes, high-pressure, or high-temperature systems.
Socket Weld Flange Face Types
Socket Weld Flanges (SW Flanges) come with different flange face types, which determine how they seal against the mating flange or gasket. The most common flange face types are:
1. Raised Face (RF) – Most Common
Description:
Has a slightly raised surface around the bore where the gasket is placed.
The raised face height depends on the pressure class:
Class 150 & 300 → 1.6mm (1/16″) raised face.
Class 400 & above → 6.4mm (1/4″) raised face.
Advantages:
✅ Common in high-pressure applications.
✅ Compatible with a wide range of gaskets (spiral wound, ring gaskets).
✅ Provides a reliable, tight seal.
2.Flat Face (FF) – For Low Pressure
Description:
The sealing surface is completely flat (no raised area).
Used with full-face gaskets to ensure even sealing.
Advantages:
✅ Ideal for low-pressure systems.
✅ Prevents stress on brittle materials like cast iron.
3. Ring-Type Joint (RTJ) – For High Pressure & Temperature
Description:
Has a machined groove for a metal ring gasket (RTJ gasket).
Provides a metal-to-metal seal for extreme conditions.
Advantages:
✅ Suitable for high-pressure (Class 600 & above).
✅ Provides a leak-proof seal even under extreme conditions.
How to Choose the Right Face Type?
| Face Type | Pressure Rating | Best for |
| Raised Face (RF) | Medium to high | General industrial use |
| Flat Face (FF) | Low | Cast iron, ductile iron, low-pressure piping |
| Ring-Type Joint (RTJ) | High to very high | Oil & gas, petrochemical, extreme pressure |
Advantages of Stainless Steel Socket Weld Flanges
Corrosion Resistance – Ideal for harsh environments, including marine and chemical industries.
Leak-Proof Connection – Strong seal with single-side welding.
Smooth Bore for Flow Efficiency – Internal bore matches pipe ID, reducing flow restriction.
High-Pressure Capability – Suitable for medium to high-pressure applications.
Common Applications
Petrochemical & Chemical Plants – Handles corrosive chemicals and gases.
Oil & Gas Pipelines – Used in high-pressure hydraulic and steam systems.
Food & Beverage Processing – Hygienic and corrosion-resistant.
Marine & Offshore – Saltwater-resistant stainless steel.
Pharmaceutical & Water Treatment – Non-reactive and hygienic.
You can get an offer for products in below material forms:
-Pipe and Tube (EN 10216-5, ASTM A213, ASTM A249, A312, A790,)
-Forged Fitting and Flange (ASTM A182 , ASTM A105,ASTM B564 )
-Butt Weld Fittings (ASTM A234, ASTM A403,ASTM A815)
-Round bar , Billet (ASTM A276, ASTM A479)
– Plate, Sheet, Strip(ASTM A240, EN 10028-7, A480)
-Bolting, Nuts（ASTM A193, A194, A320）
Stainless Steel Socket Weld Flange Exported Countries
We Export Stainless Steel Socket Weld Flange to Saudi Arabia, United Arab Emirates, Qatar, Bahrain, Oman, Kuwait, Turkey, Egypt, Yemen , Syria, Jordan, Cyprus, Singapore, Malaysia, Indonesia, Thailand, Vietnam, South Korea, Japan, Sri Lanka, Maldives, Bangladesh, Cambodia, Argentina, Bolivia, Brazil, Venezuela, Colombia, Ecuador, Guyana, Paraguay, Uruguay, United States Of America, Canada, Mexico, Panama, Jamaica, Bahamas, Denmark, Norway, Germany, France,Italy, United Kingdom, Spain, Belgium, Greece, Czech Republic, Portugal, Hungary, Albania, Austria, Finland, Ireland, Croatia, Malta, Nigeria, Algeria, Angola, South Africa, Libya, Egypt, Sudan, Europe, Africa, Asia, North America, South America, Middle East.etc
We are professional in manufacturing and exporting flanges in various materials.
