The primary distinction between a coupling and a union lies in their purpose: a coupling serves to join two pipes together or connect a pipe to a swedge, often used to extend the pipeline. In contrast, a union allows for easy disassembly of piping system components, such as valves or traps, facilitating maintenance or replacement. This choice is not governed by code but rather by the specific requirements of the application. A pipe coupling is a compact, cylindrical component used to connect two pipes, ensuring a secure and seamless fit. It achieves this connection via threading, where the seal is maintained through the threads. When disassembling, it’s best to start from one end to prevent damage. These are widely used to extend pipelines when the length of a single pipe isn’t sufficient. Pipe couplings are manufactured from materials such as carbon steel, stainless steel, alloy steel, PVC, and plastic, offering versatility across industries. Threaded connections, welding, and socket fittings are common methods used to ensure a reliable connection in diverse applications. Industry standards include ASME B1.20.1, DIN2986, and BS10241, ensuring quality and compatibility. Forging involves heating steel to shape it and then threading it on a lathe. Casting, on the other hand, involves melting steel and pouring it into molds to solidify. Due to their simplicity and reliability, pipe couplings are indispensable in construction, industrial systems, and agricultural setups. A pipe union is a versatile connector designed for easy installation and removal. Comprising three main parts—nut, body, and gasket—it facilitates quick disassembly. Unions are frequently found at the ends of valves, water meters, and other devices, enabling routine maintenance without disturbing the entire system. Commonly made from materials like carbon steel, stainless steel, brass, and plastics such as PVC and PE, unions are chosen for their strength and corrosion resistance. Unions can be connected via socket welding or threading. Socket welding involves inserting a pipe into a socket and welding it, while threading connects the pipe by screwing it into place. Standards like ASME B16.11 and MSS SP 83 guide the production of unions to ensure quality and safety. Unions come in equal and unequal diameter configurations, catering to various piping needs. Both couplings and unions fall under the category of pipe fittings. While couplings primarily extend pipelines, unions enable the disassembly of components like valves or traps for maintenance. Unlike couplings, unions allow for easier access during repairs. Couplings are typically used in high-pressure situations, whereas unions are suited for lower-pressure applications. Pipe couplings include options like threaded, butt-welded, and socket couplings, while unions are predominantly threaded or socket-based. Socket unions require threading to secure the connection, whereas unions simply need to be aligned and tightened to connect. From a practical standpoint, unions are ideal for low-pressure settings, while couplings excel in high-pressure environments. Unions are usually limited to pressures below 10 kg/cm² in public installations. Pipe couplings offer superior durability and can withstand harsh conditions thanks to their robust materials. Their straightforward design makes them easy to install, and they provide excellent sealing to prevent leaks. Couplings also allow for flexible connections between different pipe sizes. However, their tight-threaded connections can be challenging to disassemble, especially in high-pressure environments. Unions are advantageous for maintenance and replacements due to their ease of disassembly. They provide flexibility in connection methods, but they may not be as robust under extreme pressure or vibration. Over time, frequent disassembly can lead to wear, so careful handling is essential to maintain their efficiency. Hebei Sanvo is a reputable manufacturer and supplier of high-quality pipe fittings in China. We specialize in producing carbon steel and stainless steel fittings, including pipe nipples and couplings, catering to diverse industrial needs. If you're interested in our products, feel free to reach out to us. We’re excited about the possibility of working together. Additional notes: While couplings and unions serve distinct purposes, both play crucial roles in modern plumbing and industrial systems. Understanding their unique features helps engineers and contractors select the right fitting for each application. Whether it’s extending a pipeline or ensuring easy maintenance, both couplings and unions contribute significantly to efficient system operation.
Zhejiang Sealand Technology Co., Ltd. is a trustworthy manufacturer of Natural Gas Mass Flow Meter, Natural Gas Mass Flowmeter, Natural Gas Coriolis Meter, Natural Gas Coriolis Mass Flow Meter, ATEX, IECEx & CE approved.
First, Sealand meter is certified by Zhejiang Institute of Metrology. To get such
certificate, Sealand has to send all models to Zhejiang Institute of Metrology
and all models are tested in their calibration lab. The lab is an ISO/IEC
17025:2005 standard lab approved by CNAS (China National Accreditation
Service for Conformity Assessment). CNAS is a member of ILAC (International
Laboratory Accreditation Cooperation).
Second, Sealand has its own calibration lab, equipped with METTLER
TOLEDO scales with accuracy 0.014% and the device extended uncertainty is
0.05%. The lab is also approved by Zhejiang Institute of Metrology. This
certificate will stay valid only for one year, Zhejiang Institute of Metrology will
send their professor to Sealand every year to check and make sure that the lab
is qualified still and then issue new certificate. During the production, each
meter will be calibrated in this lab for 3 times, each time at 5 different flow rate.
Finally, Sealand also gets ISO, CE, SIL, ATEX & IECEx. Sealand is the only
Chinese brand who gets ATEX & IECEx and it is from TUV SUD ( the most
authoritative institute for ATEX).
Natural Gas Mass Flow Meter, Natural Gas Mass Flowmeter, Natural Gas Coriolis Meter, Natural Gas Coriolis Mass Flow Meter Zhejiang Sealand Technology Co., Ltd. , https://www.sealandflowmeter.com1. Understanding a Pipe Coupling
Materials
Connection Methods
Manufacturing Standards
Manufacturing Process
Applications
 2. Exploring the Pipe Union
Materials
Connection Forms
Manufacturing Standards
Types
 3. Pipe Coupling vs Union
4. Pros and Cons
5. About Us