Polyethylene threaded fittings are divided into three types: threaded, welded, and compression. Threaded fittings connect to the female ends of pipes using threads inside or on the fittings and are used for small projects and small pipes. These polyethylene threaded fittings come in various types, which we will discuss below.
Threaded fittings (threaded connections) are used to connect two polyethylene pipes without the need for welding. These fittings consist of different parts and are mainly used in water supply systems and irrigation of agricultural and farmland. Threaded fittings are made of polyethylene and produced by injection molding.
Polyethylene Threaded Fittings
Types of Polyethylene Threaded Fittings
Polyethylene fittings include female fittings, male fittings, flanged fittings, polyethylene couplings, equal tees, equal elbows, female elbows, male elbows, female tees, male tees, end caps, and reducing tees.
Female Fitting
This type of fitting is used to connect to valves and male threaded polyethylene fittings. For a more secure and reliable connection, it is better if both fittings are of the same material and family.
Male Fitting
This fitting has one end as a coupling and the other end threaded. This type of polyethylene threaded fitting is used to connect polyethylene pipes to threaded valve fittings.
Flanged Fitting
This type is also threaded and is used to connect polyethylene pipes to cast iron valves or any flanged connection. The flange is made of steel and can be easily opened and closed using bolts and nuts. It is used in pressure vessels, compressors, pumps, and more.
Polyethylene Coupling
This complex fitting is used to connect two ends of polyethylene pipes and can increase the pipes' resistance to stretching, expansion, and contraction.
Equal Tee
This fitting is used to take a branch and comes in various sizes. It is used in water supply, irrigation, and gas distribution industries. Since all three connections are equal and identical, it is called an equal tee and is used as a divider, connector, changer, and joiner.
Applications of Polyethylene Threaded Fittings
Fittings are available in various sizes and qualities for fields such as agriculture, household and construction uses, urban and industrial sewage, fisheries, and more. They are also widely used in the transmission of gas and chemicals. Polyethylene threaded fittings have high resistance to weather changes, corrosion and abrasion, pressure, and impact. Additionally, their non-scaling, ease of installation, long lifespan, reasonable price, and flexibility make them among the most commonly used fittings.
Urban and rural water supply systems
Non-potable water networks (such as green spaces and parks)
Industrial installations for transferring acidic and alkaline chemicals
Drip and sprinkler irrigation networks in agriculture (under pressure)
Use in transporting wastewater and industrial sewage
Advantages of Using Polyethylene Threaded Fittings
Durability and Longer Lifespan
These fittings have a longer lifespan and durability compared to similar metal, steel, and cast iron fittings. Depending on the application, design model, and installation location, their average lifespan is estimated between 50 to 100 years.
High Corrosion Resistance
A common problem in metal piping is corrosion (both internal and external), which affects hydraulic efficiency and incurs high costs for consumers. Using polyethylene threaded fittings ensures very high resistance to corrosion.
No Need for Specialized and Heavy Tools
To create connections with polyethylene threaded fittings, you do not need specialized or heavy tools and can install fittings using basic tools.
No Need for Protective Coatings
Many fittings require protective coatings to resist rust and other issues, but threaded fittings do not need special protection.
Low Cost
These fittings are much more cost-effective compared to others. The impact and pressure resistance and flexibility of polyethylene pipes and fittings are sufficiently high, eliminating the need for anti-impact equipment.
Minimal Space Required for Installation
Threaded fittings can be installed in very limited spaces without needing large areas.
No Expertise Required
Unlike welded fittings that require skilled specialists, threaded fittings can be installed without any special expertise.
Speed of Work
Installation of threaded fittings is much faster compared to other types, allowing completion in minimal time.
Advantages of Threaded Fittings
Long Lifespan: Since threaded fittings are made of polyethylene, they can be used with confidence due to their long lifespan.
Easy Installation: Due to their threaded nature, they do not require high technical knowledge, additional equipment, or skilled labor for installation.
Easy Repairs: As installation is easy, replacement and repairs are also simpler compared to other models.
High Temperature Resistance: These fittings can withstand temperatures even above 80°C.
High Pressure Resistance: Threaded fittings can tolerate pressures up to 10 bar, making them popular in industries.
Minimal Leakage: Due to their structure, threaded fittings have the lowest leakage rates.
Components of Polyethylene Threaded Fittings
1- Split Ring
The split ring prevents the pipe from coming out of the fitting under pressure. It is made of polyacetal, which can withstand high pressure.
2- Bushing
The bushing is placed between the O-ring and the split ring and presses the O-ring during connection to enhance sealing.
3- O-ring
Made of rubber, the O-ring must be highly flexible and pressure-resistant. Its function is to seal the connection.
4- Body and Nut
The body and nut of threaded fittings are made of polypropylene, which has higher resistance to pressure, temperature, and UV rays compared to polyethylene.
The ends of the pipes to be connected must be clean in all respects, and the fitting parts are installed on the pipe. The handle length for these fittings is no more than 46 cm; otherwise, Teflon tape is required. The list below includes types of polyethylene threaded fittings:
Equal Elbow
Male Elbow
Reducer Tee
Female Tee
Male Tee
Tee (Equal Tee)
Saddle
Reducer Nipple
Polyethylene Flange Adaptor
Female Polyethylene Threaded Adaptor
Male Adaptor
Threaded End Cap
Reducing Coupling
Coupling
Female Elbow
Due to their unique features, polyethylene pipes and fittings are used in very large industrial projects.
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