On July 16, 2025, our domestic customer sent us another inquiry. This customer had already purchased from us several times in recent months, and our partnership was very strong. This time, their request included a variety of SS316L pipe fittings and flanges. Upon receiving the inquiry, we quickly developed a detailed quotation proposal and provided recommendations on the optimal material and process based on the customer’s operating environment, ensuring the product’s corrosion resistance and long-term stability. The customer was very satisfied with our quotation and service and placed an order the next day.
Product List
| ITEM | DESCRIPTION | QUANTITY | UNIT |
| 1 | WN RF CL300 A182-F316L ASME B16.5 SCH40S | 6 | piece |
| 2 | Concentric Reducer ASTM A403 Gr.WP316L ASME B16.9 SCH80S×SCH80S | 3 | piece |
| 3 | Threaded Union 1-1/4″-12UNF-2B×1FNPT 3000# ASTM A182.Gr.F316L MSS-SP-83 | 3 | piece |
| 4 | Threaded Union 1-3/4″-12UNF-2B×1-1/2FNPT 3000#ASTM A182.Gr.F316L MSS-SP-83 | 3 | piece |
Inspection Photos
ASME B16.9 Concentric Reducer Specification
Stainless steel 316 concentric reducers are fittings used to connect two pipes of different diameters. Their primary function is to alter the pipe diameter and flow velocity, ensuring smooth fluid flow within the piping system.
| Size Range | 3/4″ – 60″ / DN20 – 1500 |
| Thickness Schedule | SCH 10 – SCH 80, SCH 160, XXS |
| America Standard | ANSI / ASME B16.9 |
| Japan Standard | JIS B2311/2312/2313 |
| Germany Standard | DIN2605/2615/2616/2617 |
| Europe Standard | EN10253 |
| Stainless Steel | ASTM A403 WP304/304L/304H, 316/316L, 310S, 317,347,904L |
ASTM A403 WP316L Pipe Fittings Chemical Composition
| CHEMICAL | LIMITS | C | Mn | P | S | Si | Ni | Cr | Mo |
| ASTM A403 WP316 | MIN | 10.0 | 16.0 | 2.00 | |||||
| MAX | 0.08 | 2.00 | 0.045 | 0.030 | 1.00 | 14.0 | 18.0 | 3.00 | |
| ASTM A403 WP316L | MIN | 10.00 | 16.00 | ||||||
| MAX | 0.03 | 2.00 | 0.05 | 0.03 | 1.00 | 14.00 | 18.00 |
ASTM A403 WP316L Pipe Fittings Mechanical Property
| MATERIAL | T.S (MPA) | Y.S (MPA) | EL % |
| ASTM A403 WP316 | 515 min | 205 min | 28 min |
| ASTM A403 WP316L | 485 min | 170 min | 28 min |
MSS SP-83 Threaded Union Specification
The threaded union is the most widely used type of union, characterized by its use of threaded connections for piping. It consists of three main components: a male end with external threads, a female end with internal threads, and a nut. By rotating the nut, the sealing surfaces of the male and female ends can be tightly aligned to achieve connection and sealing. The thread forms can be BSP, NPT, G, etc., and the connection is further secured by a locking nut and seal ring.
| Size: | 1/8″ to 3″ / DN6 to DN80 |
| Pressure: | 3000 LB |
| Connection: | Threaded Union |
| Thread Type: | Female and Male NPT, BSPP and BSPT |
| Stainless Steel: | ASTM A182 F304, F316, F317, F310, F321 |
Class 3000 Threaded Union Dimensions
| Nominal Size | Pipe End | Wall | Bone | Male Flange | Nut | THRD Per Inch | Bearing | Length Assem | Clear Assem Nut | |
| DN | NPS | Amin | Cmin | D | Fmin | Gmin | H | Jmin | Lnom | N |
| 6 | 1/8 | 14.7 | 2.4 | 8.46.4 | 3.2 | 3.2 | 16 | 1.2 | 41.4 | 51 |
| 8 | 1/4 | 19.1 | 3.0 | 11.19.4 | 3.2 | 3.2 | 16 | 1.2 | 41.4 | 51 |
| 10 | 3/8 | 22.9 | 3.2 | 14.313.5 | 3.4 | 3.4 | 14 | 1.4 | 46.0 | 56 |
| 15 | 1/2 | 27.7 | 3.7 | 17.917.1 | 3.7 | 3.7 | 14 | 1.5 | 49.0 | 59 |
| 20 | 3/4 | 33.5 | 3.9 | 23.021.4 | 4.1 | 4.1 | 11 | 1.7 | 56.9 | 66 |
| 25 | 1 | 41.4 | 4.5 | 29.027.7 | 4.6 | 4.4 | 11 | 1.9 | 62.0 | 79 |
| 32 | 11/4 | 50.5 | 4.9 | 37.735.4 | 5.3 | 5.2 | 10 | 2.1 | 71.1 | 94 |
| 40 | 11/2 | 57.2 | 5.1 | 43.541.2 | 5.8 | 5.6 | 10 | 2.3 | 76.5 | 112 |
| 50 | 2 | 70.1 | 5.5 | 55.652.1 | 6.6 | 6.4 | 10 | 2.7 | 86.1 | 132 |
| 65 | 21/2 | 85.3 | 7.0 | 66.364.3 | 7.5 | 7.1 | 8 | 3.1 | 102.4 | 150 |
| 80 | 3 | 102.4 | 7.6 | 82.677.3 | 8.3 | 8.0 | 8 | 3.5 | 109.0 | 176 |
Specification of Weld Neck Flange
316L weld neck flanges are pipe connectors made from 316L stainless steel. They achieve a secure connection by butt-welding the pipe and are commonly used in applications involving high pressure, high temperature, and highly corrosive media. The high structural strength and excellent sealing properties of 316L weld neck flanges ensure the long-term safe operation of pipeline systems.
| Shape Type | Regular and Long Neck |
| Sealing Face | RF, FF, FTJ |
| Size Range | 1/2″ – 48″/ DN15 – DN1200 |
| Pressure Rating | Class 150, 300, 600, 900, 1500, 2500lb |
| Standard | ASME B16.5, ASME B16.47 Series A/B |
| Stainless Steel | ASTM A182 F304/304L/304H, 316/316L, 310S, 317,347,904L |
ASTM A182 F316L Flanges Chemical Composition
| CHEMICAL | LIMITS | C | Mn | P | S | Si | Ni | Cr | Mo | N |
| 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 | 0.10 | |
| ASTM A182 F316L | MIN | 10.00 | 16.0 | 2.00 | ||||||
| MAX | 0.03 | 2.00 | 0.045 | 0.030 | 1.00 | 15.00 | 18.0 | 3.00 | 0.10 |
ASTM A182 F316L Flanges Mechanical Property
| MATERIAL | T.S (MPA) | Y.S (MPA) | EL % | R/A % |
| ASTM A182 F316 | 515 min | 205 min | 30 min | 50 min |
| ASTM A182 F316L | 485 min | 170 min | 30 min | 50 min |
Advantages of SS316L
1. Excellent Corrosion Resistance
SS316L contains 2-3% molybdenum in its chemical composition, which gives it significantly better corrosion resistance than 304 stainless steel in chloride environments. It effectively resists pitting and crevice corrosion, making it ideal for marine environments, coastal areas, and applications involving chloride-containing media.
2. Excellent Welding Performance
“L” stands for “Low Carbon.” SS316L has a carbon content below 0.03%, significantly reducing the risk of carbide precipitation (also known as “sensitization”) during welding. This property prevents intergranular corrosion near the weld seam, ensuring the integrity and long-term stability of the welded joint in corrosive environments. Therefore, in pipeline systems requiring extensive welding, SS316L is a superior choice over 316.
3. High strength at high temperatures
SS316L maintains high tensile strength and creep strength even at high temperatures. This makes it suitable for high-temperature, high-pressure piping systems, such as heat exchangers and pressure vessels.
Applications of SS316L Fittings and Flanges
Petroleum and Natural Gas Industry
Chemical and Pharmaceutical Industry
Marine Engineering and Shipbuilding
Food and Beverage Processing
Power and Nuclear Energy