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Brazil---AimeeIn the latest vendor rating, TOBO won the excellent rating, it is good, will continue to cooperate. -
Thailand ---Dave MulroyASTM A213 T9 Alloy steel pipe ,Stable quality , good price, excellent serive, TOBO GROUP is our trustworthy partner . -
USA ---AlfaroASTM A182 F55 Super Duplex Flange ,Good quality , we like that ! And delivery time in time also ,very professional.
Forged Socket Welding Coupling ASTM A182 UNS S31803 Duplex Stainless Steel DN20 ASME B16.11
| Wallthickness | Schedule 10 To Schedule 160 | Product Type | Carbon Steel Caps |
|---|---|---|---|
| Sizerange | 1/2 Inch To 48 Inches | Material Grade | N08020 |
| Manufacture Standard | ASME,MSS SP-44,JIS, API,DIN | Surfacefinish | Polished, Painted, Galvanized |
| Corrosion Resistance | High | Shapetypes | Elbow, Tee, Reducer, Cap, Stub End |
| Function | Quick Locking | Standard | Oil Gas Water Industrial |
| End Type | Threaded | Shape | Reducing |
| Head Code | Round | Outer Diameter | 1'' |
| Technics | Forged |
Forged Socket Welding Coupling ASTM A182 UNS S31803 Duplex Stainless Steel DN20 ASME B16.11
1. Product Description
This product is a forged socket welding coupling manufactured from ASTM A182 UNS S31803 in accordance with ASME B16.11 standards . A coupling is a fundamental fitting used to join two sections of pipe in a straight line . The socket weld (SW) connection involves inserting the pipe into the fitting's socket and applying a fillet weld around the joint . Duplex 2205 is a dual-phase stainless steel with roughly equal proportions of austenite and ferrite, offering roughly double the yield strength of standard 300-series austenitic stainless steels and exceptional corrosion resistance . This DN20 (3/4") Class 3000# fitting is designed for permanent, leak-proof connections in demanding small-bore piping systems.
2. Key Product Parameters
| Parameter | Details / Range |
|---|---|
| Dimensional Standard | ASME B16.11 |
| Material Standard | ASTM A182 / ASME SA182 |
| Material Grade | UNS S31803 (Duplex 2205 / F51) |
| Type | Full Coupling – Socket Weld (SW) |
| Nominal Size | DN20 (3/4" NPS) |
| Connection Type | Socket Weld (Fillet weld) |
| Pressure Class | 3000# |
| Tensile Strength (min) | 620 MPa (90 ksi) |
| Yield Strength (min) | 450 MPa (65 ksi) |
| Elongation (min) | 25% |
| Hardness (max) | 293 HBW |
| PREN Value | ~34-36 |
| Heat Treatment | Solution anneal 1020-1100°C, water quench |
3. Application / Usage
This socket weld coupling is ideal for high-pressure and corrosive service:
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Oil & Gas: Offshore platforms, subsea piping, high-pressure process lines
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Chemical Processing: Chloride-containing acids, brine services
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Desalination: High-pressure reverse osmosis piping connections
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Marine & Seawater Systems: Fire water, cooling water systems
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Instrumentation: Connections requiring leak-proof integrity
4. Advantages
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Superior Strength: Yield strength is approximately double that of 316L austenitic steel, enabling thinner wall designs
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Excellent Corrosion Resistance: PREN ~34-36 provides outstanding resistance to pitting, crevice corrosion, and chloride stress corrosion cracking
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Leak-Proof Connection: Socket weld with fillet weld provides high leak resistance, ideal for flammable, toxic, or high-pressure fluids
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Vibration Resistance: Excellent performance on lines subject to vibration and thermal cycling
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Cost-Effective: Higher strength offsets per-kilogram cost premium over 316L
5. Functions
The socket weld coupling joins two sections of small-bore pipe (NPS 2 or smaller) in a straight line . It provides a permanent, pressure-rated, leak-proof joint for piping system extension or repair . For DN20 (3/4") Class 3000#, it serves as a durable inline connection for critical service applications requiring welding.
6. Installation Instructions
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Preparation: Clean pipe ends and coupling socket of all contaminants
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Expansion Gap: Insert pipe leaving 1/16" (1.6 mm) gap between pipe end and socket bottom before welding
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Welding: Perform fillet weld around the joint using qualified WPS and certified welders
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NDT: Visual and PT/MT examination recommended for fillet weld
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Cleaning: Post-weld cleaning and inspection as per procedure
7. Precautions
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Expansion Gap: The 1/16" gap is mandatory to prevent thermal expansion cracking
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Temperature Limitation: Maximum service temperature ~315°C (600°F)
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Ferrite Balance: Heat treatment (solution anneal) required to maintain 40-60% ferrite content
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Quality Testing: Ferric chloride pitting test per ASTM A923 Method C recommended
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NACE Compliance: Hardness below 28 HRC required for sour gas service
8. Shipping & Delivery
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Standard delivery time is typically 15–30 days, subject to order quantity and specification availability.
9. Payment Terms
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Common international payment methods include T/T (Telegraphic Transfer) and L/C at sight (Letter of Credit) .
10. Packaging
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Products are securely packed in plywood cases or wooden crates with internal cushioning to ensure safe transportation and prevent damage during transit .
11. After-Sales / Return & Warranty Policy
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All products undergo 100% strict quality inspection before shipment, with Mill Test Certificates (EN 10204 3.1/3.2) available .
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In case of quality issues, retain original packaging and provide relevant photos or third-party inspection reports.
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Specific return, exchange, and warranty terms are subject to the final sales contract agreement.


FAQ
1. Are you trading company or manufacturer ?
We are manufacturer ,You can see the certification.
2. How long is your delivery time?
Generally it is 5-10 days if the goods are in stock. or it is 15-20 days if the goods are not in stock, it is according to quantity.
3. Do you provide samples ? is it free or extra ?
Yes, we could offer the sample for free charge but need pay the cost of freight.
4. What is your terms of payment ?
Payment<=1000USD, 100% in advance. Payment>=1000USD, 50% T/T in advance ,balance before shippment.

