Pex Tubing (part 2)
– PEX tube fittings and tools.
– PEX grading, sizes and color-coding.
PEX tube fittings and tools.
PEX is generally considered a good choice, especially if need to repair or repipe your existing copper or galvanized water lines. One of the reasons for this is low price and ease of use when connecting PEX tubes together or with brass and other types of pipes.
Materials used for PEX fittings are brass but there are also available fittings manufactured of stainless steel, plastic and bronze.
Crimp/clamp PEX fittings
Crimp/clamp fittings are the most common and affordable type of PEX fittings.
These fittings require a crimp tool, which uses copper crimp rings or a clamp with a stainless steel clamp ring to secure a successful connection.
Compression PEX Fittings
Compression style fittings do not require any special PEX tool. A compression fitting consists of three parts: a compression nut, a compression ring, and a compression insert. Major advantage of compression fittings is their ease of use. Compression fittings are a good choice when a repair or small number of connections is required and you want to avoid purchasing an expensive tool.
Push PEX Fittings
Similar to compression fittings, push fittings do not require any special PEX tools or rings to make a connection with tubing. A special composite mechanism securely locks and seals the pipe, preventing it from leaking or popping out of the fitting.
Expansion PEX Fittings
Expansion style fittings can be used only with PEX-tubing and are not compatible with other PEX tubing types. Expansion fittings require expander tool and sleeves.
Press PEX Fittings
Press fittings are installed using a PEX press tool and press sleeves. Press fittings are growing in popularity with professionals.
PEX grading, sizes and color-coding.
The PEX tube comes with 20-25 years warranty and is commonly manufactured in 3/8″, 1/2″, 5/8″, 3/4″ and 1″ sizes, with three grades for water PEX-A, PEX-B and PEX-C. Difference between PEX-A, PEX-B and PEX-C is in manufacturing process, more precisely in cross-linking method used. These grades are used only to identify the manufacturing process (cross-linking method used) and give very slight differences in quality and performance ratings. The tube will be marked on the outside to show which codes it meets.
Which grade to choose?
Some of important facts of each grade, which need to take into consideration when choosing grade for your project are:
PEX-A being slightly more flexible, it is in usage for 50 years and have few reported issues. One of downsides for PEX-A is chemical leaching – from 50% to over 200% higher than PEX-B. PEX-A also comes is as much as 3 times higher price than other two options.
PEX-B is overall best choice for common applications, in terms of the performance and price. For 40 years of usage there are no know issues.
While PEX-C may be suitable for hydronic and radiant heating use, it offers little practical advantage over PEX-A and PEX-B grade.