Better Than Copper
We Will Cover The Following on This Page
• PEX Installation vs. Copper, Why Choose PEX
• Choosing the Right Brand of PEX
• PEX-a, PEX-b, PEX-c – What the Ratings Mean
• Which PEX type to Choose
• Installation Options
• Home-run Installation
• Remote Manifold Installation
• Structured Plumbing Installation
• Modified Home-run Installation
• Run-and-Branch Installation
• PEX Tools & Connections
• Selecting the Right Tool, Fittings, & Pipe for Your Job
• ProPEX Fitting Connection
• PEX Fitting Connections (For use with Clamp Tool)
• Compression Fitting Connections
• SharkBite PEX Fittings
PEX Installation Plumbing involves PEX tubing, PEX fittings, PEX manifolds or Plumbing Manifolds, and the PEX Tools that accompany these parts.
These PEX Installation Plumbing resources will help you to learn more about the benefits of using PEX and how to make the best choices when designing your system.
PEX Installation vs. Copper, Why Choose PEX
There are several reasons why PEX Installation is quickly replacing copper in many plumbing applications throughout the United States.
These include lower cost of material, the level of difficulty of making connections which also leads to lower labor costs, the likelihood of pipes bursting, product availability and color coating.
Choosing the Right Brand of PEX
AquaPEX, HydroPEX, Viega, Watts, Zurn, the list goes on and on. There are now more than 20 different brands of PEX tubing for plumbing systems on the market!
It can be difficult to decide which brand to go with and to have a good reason for the choice.
Let’s simplify the decision making process: AquaPEX, made by Wirsbo (Uponor) is the highest quality tubing available on the market today.
AquaPEX is PEX-a tubing and therefore is more homogeneous (with the chemical bonds evenly spread out) making it both stronger and more flexible.
These characteristics come from the Engel production method for PEX-a tubing. Because of the tubing’s strength it is able to hold up better to freezing conditions, and it can be unkinked using a heat gun.
It is also the only brand of PEX installation plumbing tubing that can be used with the Wirsbo Expander System.
All other brands of PEX tubing can be looked at as a group.
When purchasing another brand of tubing, be sure the product is being made by a reputable manufacturer, has at least a 20 year warranty, meets ASTM standards, and meets the desired pressure ratings.
If you follow these guidelines you will come up with a group of products that includes HydroPEX, Viega PEX, Watts PEX, and Zurn PEX. When comparing these products, price or brand preference will often be the deciding factor.
Learn more about Pex Installation Basics including a series of great videos.
- Pex Plumbing Introduction
Check out Pex Installation Basics to see this entire video series.Return to TOP
PEX-a, PEX-b, PEX-c – What the Ratings Mean
PEX stands for Poly Ethylene Cross (X)-Linked.
It is the cross-linking process that makes PEX strong, safe and reliable, and it is how this process is done that determines what grade, or category, the PEX belongs to.
Depending on the grade of PEX that you choose, the flexibility, strength, and uniform nature of the material will be affected.
The letters tell you how the PEX was created and the quality of the PEX, with “A” being the highest grade, followed by “B’, and finally “C”.
PEX-a is made using the Engel (or peroxide) method to crosslink the molecules of polyethylene.
With this method, the crosslinking is done at a high temperature above the melting point of the crystals. This “hot crosslinking” produces an incredibly uniform material with no weak spots.
The Engel method produces the strongest, most flexible PEX tubing possible, allowing for an installation with fewer joints and fittings than any other type of PEX.
PEX-a also features a strong thermal memory and freeze protection, which means that once the tubing is expanded or contracted, it will naturally go back to its original shape. Since the process takes more time and more sophisticated equipment,
PEX-a tends to be a bit more expensive than PEX-b or PEX-c. AquaPEX is the only PEX-a material available for plumbing applications. Examples of PEX-a for Radiant Heat include ThermaPEX and hePEX.
PEX-b is made using the Silane (or moisture cure) method.
This method performs the crosslinking with a chemical agent where the process is accelerated using heat and moisture.
This chemical crosslinking is susceptible to some areas where the bonds are weaker than others and a slightly stiffer final product than PEX-a.
Examples of PEX-b include HydroPEX, Watts PEX, and Viega PEX.
PEX-c is made using the Electron beam (or radiation) method.
This method takes the polyethylene and passes it under an electron beam multiple times in order to get to the desired level of crosslinking.
This is the most energy-efficient method of creating PEX, but often results in a more brittle, less consistent product than PEX-a or PEX-b.
Electron beam is also the least expensive method and therefore creates the least expensive tubing.
Which to Choose
When deciding which grade of PEX is right for your application, you should think about the layout of your tubing.
If many tight bends need to be made, it is likely worth the extra few dollars for PEX-a so that you can avoid breaks in the tubing to insert elbows.
PEX-a is also probably worth the extra money if the tubing will be exposed to very cold temperatures or to make the installation process easier.
Pex Plumbing system design can be done in a similar fashion to traditional Plumbing Systems.
However, because of its flexibility PEX saves time and money as compared to installing traditional copper plumbing systems.
The options for running PEX in a plumbing system are listed below, they are not listed in any preference order.
In this system central manifolds are used to distribute water to all of the fixtures in a given residence or building. Manifolds may either be valved or valveless and are generally made of copper or engineered plastic.
If they are valveless, shutoff valves must be used at each fixture. These manifolds contain between 3 and 12 ports (generally 1/2″) to connect PEX Tubing to.
One of the central manifolds will receive cold water, and one manifold will receive the hot water supply.
Each fixture will then have one dedicated cold PEX Tubing line and one dedicated hot PEX Tubing line which begin at the manifolds.
Using this method minimizes the overall number of connections required. This method also takes advantage of the flexibility of PEX Tubing.
One main benefit of this setup is the reduced time required for hot water to reach the fixture.
Remote Manifold Installation
In this PEX Plumbing installation method close-end remote manifolds are placed near groups of fixtures, i.e. a bathroom.
Two manifolds, one hot and one cold are placed close to the group of fixtures. PEX Tubing is then run from the manifold to each fixture.
Valveless manifolds are typically used, however valved manifolds may be used as well.
Structured Plumbing Installation
Structured PEX Plumbing systems make use of the recirculation of hot water. Manifolds in this system will be located near groups of fixtures.
For the hot water lines, open ended manifolds are used. By doing this, the hot water return line is created as an extension of the hot water supply line.
This system’s main benefit is a reduction in the usage of water and energy due to the on demand recirculation.
Modified Home-run Installation
This method is similar to home run installation, but it uses several flow-through manifolds instead of central manifolds. These open ended manifolds may be either valved or valveless.
This method uses less PEX tubing than the home run method and may provide hot water faster than other installation methods.
This method is also referred to as “teeing off”. It is commonly used in rigid plumbing systems such as copper and CPVC.
A PEX fitting such as a tee or elbow is used each time the tubing needs to be split or change direction. This method requires more connections than other methods of PEX Plumbing.
This method does not take full advantage of the flexibility of PEX Tubing.
For all of these installations the system should be inspected and pressure tested prior to being filled with water. The system should be pressure tested to between 40 and 60 psi.
PEX TOOLS & CONNECTIONS
With so many PEX tools and fittings available it can often be difficult to select the right tool for your job.
The information and compatibility table on this page will help you make the right choice for your job.
PEX Plumbing – Selecting the Right Tool, Fittings, & Pipe for Your Job
If you are a DIY and have a one-time PEX job with a small number of connections you can utilize the SharkBite connection system.
SharkBite fittings are easy to use and although they are expensive per fitting, they don’t require a PEX tool.
Therefore the simplest and most inexpensive way for a DIY to complete a small PEX job is with SharkBite PEX fittings.
They can’t be used with PEX-AL-PEX pipe.
For DIY’s or professionals with a large one time job, or if you plan on having PEX jobs in the future, you will have several different options.
These options include the Wirsbo Expander System, the PEX Crimp system or the PEX Clamp system, and the Viega Press System. We will discuss each of these in more detail and make some basic recommendations.
The PEX Crimp System and PEX Clamp System are the most simple and most often used by DIY’s, however they are also popular with professionals in certain areas of the country.
Both of these systems make use of the same barbed crimp fittings. The difference between the two fittings is that the PEX Crimp System uses a Crimp tool and copper crimp rings, while the PEX Clamp System uses a Clamp Tool and stainless steel clamps.
In terms of a recommendation here, the clamp system is slightly easier to use and cheaper.
These systems can be used with any standard ASTM size PEX pipe, but can’t be used with PEX-AL-PEX.
The Uponor Wirsbo Expander system is perhaps the most widely used PEX system by professionals in the US. This system makes use of the ProPEX Expander Tool ProPEX Fittings, ProPEX Rings, and PEX-a tubing.
If PEX-a tubing (AquaPEX) is not used the connections will fail. This system makes strong reliable connections that have never failed in the field.
The only downsides to this system are the high up-front cost of the tool, the high price of fittings, and the fact that Wirsbo only wants professionals using the tools.
Wirsbo has addressed the price of fittings by coming out with engineered plastic fittings that are more cost effective. Using the tool can be a little tricky at first, and Wirsbo prefers that only professional installers use their products.
The Viega PEX Press System is growing in popularity with professionals across the country. It has recently become available to DIY’s through the Internet.
This system utilizes a Viega PEX press tool PEX press fittings, and Press Sleeves. Some people have tried to use the PEX Press tool with crimp fittings, and for the most part it has worked, but this is not recommended by the manufacturer, and they will not honor the warranty if a leak occurs.
Contractors in our local area enjoy working with this tool due to its ease of use and the strong connections it makes.
The Press technology is unique to Viega and has been used for many years. Similar to the Expansion system, the only down sides to this system are the high up-front cost of the tool, the high price of fittings, and the fact that Viega only wants professionals using the tools.
This system can be used with any standard ASTM size PEX pipe, and Viega FostaPEX Tubing.
ProPEX Fitting Connection
Cut the end of the tubing perpendicular to the length of the tube. All of the material or burrs that are created from the cut should be removed.
Slide the ProPEX ring over the end of the PEX Tubing. The ring should be extended over the tube by 1/16″.
Separate the two handles of the tool, and slide the expander head into the PEX until it stops. Bring the handles together to expand the tubing.
Remove the head from the tube and rotate a 1/8″. Slide the tool head into the tubing in the newly rotated position and expand again. Repeat the expansion process until the tubing and ring are snug against the shoulder of the expander head.
For 1/2″ make 2-3 expansions, 5/8″ make 5-7 expansions, 3/4″ make 7-9 expansions, and 1″ make 12-14 expansions.
When tubing is expanded, remove the tool, and insert the fitting. There will be some resistance as the tubing slides over the fitting.
The tubing and ProPEX ring must be seated against the shoulder of the fitting to secure a proper connection.
Note: ProPEX connections can’t be made for PEX-AL-PEX Tubing.
PEX Fitting Connections (For use with Clamp Tool)
Clamping connections may be made on any brand of PEX Tubing. However, it may not be used on PEX-AL-PEX Tubing. Clamps come in 3/8″, 1/2″, 5/8″, 3/4″, and 1″.
These clamps all work with the same clamping tool and may be used with the different sizes of PEX Tubing.
Cut the PEX Tubing so a straight end is created. Slide the clamp over the end of the tube. Insert a SSC fitting into the tube so that the tube is fully covering the inserted barb.
The clamp should then be moved between 1/8″ – 1/4″ from the end of the tube. Place the opened jaws of the ratchet tool over the ear of the clamp. Compress the tool until you feel a click, then lock it in a perpendicular position.
Compress the tool handles together to complete the connections. The tool will release when assembly is complete. Note: Crimp/Clamp connections cannot be made for PEX-AL-PEX Tubing.
Compression Fitting Connections
Compression fittings may be used to make connections for PEX and PEX-AL-PEX tubing. Compression fittings do not require a special tool.
SharkBite PEX Fittings
SharkBite Push-Fit Fittings are designed to simplify pipe installation.
The fittings allow users to connect pipe in seconds with ease. Instant push-fit connection for increased ease of use.
Certified to 200 psi and 200°F (93°C). Fits OD controlled copper, CPVC, or PEX pipe. Body composed of solid DZR brass.