Comprehensive Guide to Industrial Fluid Fittings: Classification, Features, and Selection - VELON INDUSTRIAL INC.

Hello everyone, welcome to the VELON Academy. Fittings are an important category of products in the industrial fluid sector, playing a crucial role in the safe transportation of fluids. In this lesson, we will guide you through understanding fitting products. Please note that the fittings introduced in our text are mechanical products and do not include any electrical types of fittings. We will introduce the definition and classification methods of fittings one by one, and we will focus on common types of fittings to help you build a systematic understanding of fitting products.

First, let's introduce the definition and classification of fittings.

What is a fitting?

The definition of a fitting is as follows: it is a component used in piping and hose systems to connect, control, or adjust fluids, such as liquids, gases, and powders.

There are various ways to classify fittings, such as by working pressure, which can be divided into industrial fittings, hydraulic fittings, and ultra-high pressure fittings; industrial fittings typically operate under 100 bar, hydraulic fittings usually under several hundred bar or higher, and ultra-high pressure fittings often require thousands of bar.

According to the gender of the fittings: there are mating fittings, which are commonly referred to as male and female fittings; there are also non-mating neutral fittings.

By the ease of connection and disconnection: there are standard fittings and quick-release fittings; quick-release fittings connect quickly and usually do not require special tools, which can be achieved by hand. Standard fittings, on the other hand, require external tools to connect and disconnect.

They can also be classified by whether they have a valve core structure: self-closing fittings and open fittings; self-closing fittings have internal valve cores or other mechanisms that can actively or passively close, blocking the flow of media. Open fittings can only conduct media and cannot block the flow.

There are also many common materials for fittings, such as stainless steel, carbon steel, brass metal materials, and various plastic materials like PTFE, PE, PVC, etc. Next, we will focus on introducing some common industrial fittings and their basic characteristics.

The first type, threaded fittings:

Threaded pipe fittings: These are threaded pipe connectors that couple male and female threads to achieve connection, usually requiring materials like Teflon tape, sealant, gaskets, etc., to achieve a seal. Common fittings include straight threads, elbows, tees, reducers, bushings, hose fittings, etc. They are widely used in various industrial scenarios. It is necessary to ensure that the thread standards are uniform when connecting. Common threads include NPT threads, metric threaded fittings, etc.

Coupling fittings: Coupling fittings are also a type of threaded fitting, but they are more convenient to connect than threaded fittings. They rely on the coupling's internal ferrule to tightly grip the steel pipe wall to achieve a seal. This design allows coupling fittings to achieve a solid, quick connection without welding or threading, and they can withstand high working pressures. They are widely used in various gas and hydraulic applications.

The second type, quick-connect fittings:

Camlock fittings: Also known as cam and groove quick connectors or lever-activated quick connectors, these fittings can be connected and disconnected by pressing the handle of the female fitting. Male and female fittings need to be used in pairs, without a valve core structure. They are widely used in industrial fields and are particularly suitable for conveying low-corrosive or non-corrosive liquids and dry powder media. It is a low-pressure product.

Dry quick-connect: Also known as Yu-style quick connectors, this product has a special core design that allows for leak-free or low-leakage connection and disconnection through rotation or other operating methods. The product has male and female heads, and both usually have valve cores. There is no ISO standard formed in the market yet. It is a low-pressure product, larger in size compared to quick-connect fittings, suitable for various fluid transfer applications, especially those involving toxic, corrosive, or radioactive media.

The third type, flange fittings:

Flange fittings: These are fittings where flanges are welded or installed at the end of pipes. Flanges have threaded holes, and two flanges are tightly connected together with bolts, requiring gaskets for sealing. There are many types of flange standards, such as American standard flanges, German standard flanges, Japanese standard flanges, etc., and there are significant size differences between different standards, which may not be compatible. Flange connections can achieve very high working pressures and are widely used in the oil and petrochemical industries.

The fourth type, sanitary fittings:

Sanitary fittings: These are lightweight pipe fitting products. This lightness refers to their low weight, small size, and delicate design. The main features of sanitary fittings are quick connection, easy cleaning and disinfection, and no dead corners inside. Common sanitary fittings include TC fittings, SMS fittings, DIN fittings, etc. The products are mainly used in the food, cosmetics, pharmaceutical, and other industries.

Of course, there are far more quick-connect fittings than those mentioned above. Common fittings such as claw fittings, steam fittings, nitrogen fittings, and other products will be shared in our detailed product section.

Finally, we introduce how to select the type.

Despite the variety of fittings, there is a simple interface for their selection, and we can refer to the universal formula STAMPED information table for hose selection. When encountering new products, first identify the general category of the product, then summarize and narrow down the working conditions and technical parameters according to the STAMPED information table, and finally select the specific product model. You see, the STAMPED information table has once again played an important role.