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

3. Application / Usage

This socket weld coupling is ideal for high-pressure and corrosive service:

• Oil & Gas: Offshore platforms, subsea piping, high-pressure process lines

• Chemical Processing: Chloride-containing acids, brine services

• Desalination: High-pressure reverse osmosis piping connections

• Marine & Seawater Systems: Fire water, cooling water systems

• Instrumentation: Connections requiring leak-proof integrity

4. Advantages

• Superior Strength: Yield strength is approximately double that of 316L austenitic steel, enabling thinner wall designs

• Excellent Corrosion Resistance: PREN ~34-36 provides outstanding resistance to pitting, crevice corrosion, and chloride stress corrosion cracking

• Leak-Proof Connection: Socket weld with fillet weld provides high leak resistance, ideal for flammable, toxic, or high-pressure fluids

• Vibration Resistance: Excellent performance on lines subject to vibration and thermal cycling

• 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

1. Preparation: Clean pipe ends and coupling socket of all contaminants

2. Expansion Gap: Insert pipe leaving 1/16" (1.6 mm) gap between pipe end and socket bottom before welding

3. Welding: Perform fillet weld around the joint using qualified WPS and certified welders

4. NDT: Visual and PT/MT examination recommended for fillet weld

5. Cleaning: Post-weld cleaning and inspection as per procedure

7. Precautions

• Expansion Gap: The 1/16" gap is mandatory to prevent thermal expansion cracking

• Temperature Limitation: Maximum service temperature ~315°C (600°F)

• Ferrite Balance: Heat treatment (solution anneal) required to maintain 40-60% ferrite content

• Quality Testing: Ferric chloride pitting test per ASTM A923 Method C recommended

• NACE Compliance: Hardness below 28 HRC required for sour gas service

8. Shipping & Delivery

• Standard delivery time is typically 15–30 days, subject to order quantity and specification availability.

9. Payment Terms

• Common international payment methods include T/T (Telegraphic Transfer) and L/C at sight (Letter of Credit) .

10. Packaging

• 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

• All products undergo 100% strict quality inspection before shipment, with Mill Test Certificates (EN 10204 3.1/3.2) available .

• In case of quality issues, retain original packaging and provide relevant photos or third-party inspection reports.

• 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.