Plumbing nipple is also known as nipple plumbing. This pipe fitting is a component that connects the middle of two sections of pipe and is used to extend, divert, reducer, or seal the piping system. It is widely used in water supply, oil and gas, chemical industry and other fields.
What is Plumbing Nipple
Plumbing nipples are short fittings with male threads on both ends. They are used to connect female fittings in piping systems. It is used to make a strong connection between pipes by means of threading, welding, and snaps. These fittings are available in sizes ranging from 0.5-inch “short fittings” to 24-inch “extension fittings”. Their main function is to extend the connection or to fit different pipe sections.
Main Types of Nipple Plumbing
Threaded Nipple
- Core feature: tapered threads (NPT standard), which tighten to form a seal.
- Applicable Scenario: Galvanized steel pipes and steel-plastic composite pipes with a diameter of ≤100mm are installed in the open system.
- However, installation requires wrapping of packing tape to prevent leakage, and when the galvanized coating is damaged, it requires wrapping of packing tape to prevent leakage. When the galvanized layer is damaged, anti-corrosion treatment is required.
Groove Fitting (Clamp Connection)
- Advantage: Simple operation, press groove → put sealing ring → clamp locking. Convenient for maintenance and disassembly, saving time and labor.
- Typical applications: air-conditioning water system, fire-fighting pipelines
- Applicable scenarios: ≥100mm galvanized steel pipes, fire-fighting overhead pipelines
Flange Joints
- Function: Flange joints are used for connecting valves, pumps and other equipment that require frequent maintenance.
- The welded parts need to be galvanized and anticorrosive for the second time; the bolts need to be tightened in diagonal order to prevent skewing.
Weld Pipe Nipple
- Structure: The pipe is inserted into the socket and then welded on the outside
- Advantages: The weld channel is on the outside, avoiding the obstruction of the flow in the pipe.
Live Joints (Quick-Fit)
- Advantage: can be quickly disassembled and installed for easy maintenance
- Common forms: internal wire live: connecting faucets, hoses
Plumbing Pipe Nipple Size Chart - ASME B36.10M Standard
Plumbing Nipple Size Chart – (ASME B36.10M) Plumbing Nipple Size Chart for Forged Steel Pipe.
Common sizes are generally 1/8 to 2.
Common lengths are 0.5 to 48. But can be flexibly customized to customer needs.
Length tolerances: ±1.5mm for ≤12″ fittings and ±3mm for longer lengths.
NPS | Outside Diameter (mm) | SCH40 Wall (mm) | SCH80 Wall (mm) | Typical Lengths (in) | Material Grades |
1/8 | 10.29 | 1.73 | 2.41 | 0.5″-12″ | A106 Gr.B |
1/4 | 13.72 | 2.24 | 3.02 | 0.5″-12″ | A790 S31803 |
3/8 | 17.14 | 2.31 | 3.20 | 0.5″-12″ | ASTM A53 |
1/2 | 21.34 | 3.73 | 5.54 | 1″-24″ | A106 Gr.B |
3/4 | 26.67 | 3.91 | 5.56 | 1″-24″ | A790 S31803 |
1 | 33.40 | 4.55 | 6.35 | 1.5″-36″ | ASTM A53 |
1¼ | 42.16 | 4.85 | 6.35 | 2″-36″ | A106 Gr.B |
1½ | 48.26 | 5.08 | 7.14 | 2″-48″ | A790 S31803 |
2 | 60.32 | 5.54 | 8.74 | 2″-48″ | ASTM A53 |
Nipple Plumbing Fittings Material Selection
Carbon Steel Fittings
The advantages of carbon steel fittings are low cost and high strength, its tensile strength ≥420MPa. However, carbon steel fittings are prone to rusting, it will rust after more than 500 hours in salt spray test. It is suitable for conveying non-corrosive fluids, such as tap water and petroleum.
Stainless Steel Fittings
Stainless steel fittings have the property of high temperature resistance, and the oxidized weight gain at 800℃ is 60% lower than that of carbon steel. Among them, 316L stainless steel is corrosion-resistant, with 2000 hours of salt spray corrosion of only 0.02mm/year. It is commonly used in chemicals, seawater, food industry.
Alloy Steel Fittings
Alloy Steel Fittings because of the addition of chromium, molybdenum elements, its yield strength ≥ 520MPa. And has a low-temperature resistance to brittle fracture, -20 ℃ impact work 78J It is suitable for high-pressure hydraulic system, extreme temperature. Suitable for high pressure hydraulic system, extreme temperature environment.
Conclusion
A plumbing nipple is the central component for connecting pipes. It has standard male threads on both ends. The common length is usually 0.5 inches – 48 inches. it has dozens of different types, which can be categorized according to material and function. The most common types are NPT fittings and socket weld fittings. Choosing the right size pipe coupling needs to be based on the use of the environment, size, performance, material, thread standard and so on for a full range of considerations.
