What Is A Close Nipple?

Understanding Close Nipples in Plumbing and Piping

1. What is a Close Nipple?

• In its most basic form, a pipe nipple is a short length of pipe with male pipe threads at both ends for connecting other fittings. Generally, there is a short distance of unthreaded pipe between the two threaded ends, depending on how far apart you need the attached fittings to be. When there is no unthreaded pipe between the two connecting ends, the pipe nipple is called a close nipple or a running nipple. In that case, connected fittings come close to touching one another, with very little nipple visibility.

• In plumbing and piping, a nipple is a fitting consisting of a short piece of thread pipe, usually provided with a male pipe threaded at each end for connecting two other pipes or fittings. The length of the nipple depends on how long the threads are. A close nipple has virtually no unthreaded area when screwed tightly between two female fittings; very little of the nipple remains exposed. In this case, the connected fittings are very close to touching each other, and you can barely see the nipples. When ordering a close nipple, indicate the diameter followed by close, for example, 1/2 x close.

2. Purpose and Functionality of Close Nipples

• Given the name, you may have figured out the purpose of a Close Nipple. The use of a close nipple allows you to create a closed, tight connection between two female-threaded steel pipes or fittings. However, there is a downside to closed nipples. The only way to tighten or loosen a closed nipple is to grip the threaded portion with a wrench. Because of this, it becomes easy for the applicator to damage the threading, requiring replacement of the nipple. Damaged threading can cause issues with your connection if not addressed. These issues may involve leaks of air, water, or other fluids based on the nipple application. There are special tools available to assist in their use.

• Narrow and small space is the best bit for using a short nipple like a closed nipple to save space because the unthreaded part is too short or hardly any, which design makes the nipple almost can screw to the end of the thread to reduce the space, let need link both sides pipes or fittings with minimize the distance.

3. Usage Challenges of Close Nipples

• Close nipples are difficult to install and remove. The closed plumbing nipple can only be unscrewed by gripping one threaded end with a pipe wrench, which may damage the threads and necessitate replacement. So, a nipple can require a specialty tool such as a nipple wrench (or an internal pipe wrench), which grips the inside of the pipe, leaving the threads undamaged.

• Due to the unique design of the closed nipple pipe, which may cause the risk of leakage, the threaded parts can become damaged during installation and removal. Please avoid overtightening; choose the right tool (nipple or internal pipe wrench); do not disassemble frequently; prevent corrosion and wear; replace parts on time to identify and resolve any problems.

4. Tools for Working with Close Nipples

• A nipple wrench is a tool for tightening or loosening the running nipple, which provides a stable grip and protects the thread from damage.

• An internal pipe wrench is a tool with a scalable internal clamping device. It will not contact directly with the external threads when installation or disassembly can avoid damage.

Choose the appropriate size of the nipple and internal pipe wrenches based on the internal diameter, and avoid excessive force to prevent damage to the inner pipe wall.

Types and Specifications of Close Nipples

5. Material Variations in Close Nipples

The close nipple pipes have common materials, including carbon steel, specifically galvanized and black carbon steel, and stainless steel close nipple pipes.

6. Standard Specifications of Close Nipples

According to the export standards, there are American standard ASTM A733, German standard DIN2982, and British standard BS EN10241 specifications.

7. Manufacturing Processes for Close Nipples

According to the process, there are welding pipe nipples and seamless close pipe nipples. Welded close pipe nipples are constructed by joining two pieces of pipe using a welding process, ensuring a strong and durable connection. These nipples often exhibit a thicker wall and enhanced pressure ratings, making them suitable for high-stress applications. On the other hand, seamless close pipe nipples are formed from a single piece of material, eliminating weld seams. This manufacturing method provides superior integrity and resistance to corrosion.

Both types are vital in various piping systems, allowing for easy connections between fittings, valves, and other components. Welded and seamless often hinges on factors such as the application pressure requirements, material compatibility, and budget considerations. Ultimately, understanding the distinctions between welded and seamless close pipe nipples is essential for ensuring the integrity and efficiency of any piping project.

8. How long is a Close Nipple?

A close nipple is typically as short as possible, with no unthreaded portion between the two threaded ends. Its length is effectively enough to allow for the full threading on each side, bringing the two connected fittings as close as possible. 

The exact length of a close nipple varies depending on the pipe size (diameter). It is generally very short, often between 1 to 1.5 inches (2.5 to 3.8 cm) for diameters like 1/2 inch or 3/4 close nipple. The length may increase slightly For larger diameters to allow for full threading. However, this increase will be minimal.

Plumbing nipples are specified by their diameter rather than their exact length, emphasizing the close connection rather than a precise measurement.

Applications and Advantages of Close Nipples

The closed pipe nipple is significant because it allows for free adjustment of the pipe position at both ends. It is commonly on fire-fighting spray pipes.

Quality Pipe Fittings from Hebei Sanvo

• Hebei Sanvo is a reputable manufacturer and supplier of pipe fittings in China. We export a wide range of threaded pipe fittings, including galvanized pipe nipples and couplings (made from carbon steel), black pipe nipples and couplings, and stainless steel pipe nipples and couplings. Additionally, we offer stainless steel threaded pipe fittings. 
• If you need specialized or custom-sized pipe fittings, please do not hesitate to contact us today or fill out our request for quote form online.