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PEX Plumbing Systems: PEX Crimp Fittings VS. Expansion PEX Fittings

pex plumbing systems

Plumbers in the market today are transitioning from copper pipes to PEX plumbing systems. This is partly attributed to the fact that PEX can be more affordable and easier to work with.

It also doesn’t hurt that PEX plumbing systems don’t require soldering, and even the seemingly complicated manifold systems are easy to install. It also works well with hot-water recirculation and home-run layouts. Plumbers who prefer efficiency over showmanship can’t get enough of PEX.

These benefits and a range of other qualities make PEX plumbing systems one of the most used water flow pipe works today. It’s no wonder why PEX is rising in popularity owing to its dynamic applications in the plumbing industry.

Let’s take a deeper look into PEX plumbing systems.

    1. Why Choose PEX Plumbing Systems
    2. PEX Crimp Fittings vs. Expansion PEX Fittings
    3. Crimp or Expansion – The Verdict

Why Choose PEX Plumbing Systems

PEX tubing was previously used in the solar and automotive industries and have now found a unique application in the plumbing industry – replacing copper pipe systems in homes.

Since the technique and product are fairly new to the industry, many plumbing contractors are still unaware of its technicalities. In contrast, many want to know if it’s a good idea to recommend PEX to their customers. Many contractors claim it to be a brilliant concept for small settings like residencies, while others call it a sham.

However, with correct installation, PEX tubing and fittings can create a different plumbing experience. Some of the reasons why PEX tubing is the new favorite:

  • PEX tubing can reduce 63% of the construction cost over its life cycle compared to copper pipe.
  • It also proves to be very environmentally friendly as it significantly reduces CO2 (carbon dioxide) emissions by 42%.
  • PEX tubing  is made from a versatile yet unique material called cross-linked polyethylene (plastic). Cross-linkage in the polyethylene makes the pipe sustain a static electric field within the tubing, giving it resilience and thermal memory. It also retains its shape wherever you bend it.
  • The elasticity and flexibility of PEX tubing makes it easy to install in any space, and differ from conventional PVC pipes and other leading plastics used for plumbing.
  • PEX tubing uses fixed joints and are less likely to burst due to pressure or temperature change. Consequently, they require fewer joints and fittings, making them less labor-intensive.

300 ft. Eastman Red PEX Tubing - 3/4 in.

Advantages That Homeowners Will Appreciate:

  • No calcium deposits
  • No water hammering issues
  • Elasticity to support frozen pipelines
  • Resistance to heat deformation
  • Easier to install, remove, and replace
  • No rusting
  • Less labor-intensive
  • Requires fewer joints
  • Flexible to fit in most spaces

You can install PEX water systems in two ways, namely:

  1. PEX Crimp Fittings (ASTM F1807 or F2159 – Crimp)
  2. Expansion PEX Fittings (ASTM F1960 – Expansion)

Let’s figure out which one would be a good fit for your next plumbing job.

PEX Crimp Fittings vs. Expansion PEX Fittings

There are numerous PEX fittings and tools on the market, but the two most commonly used today are F1807 Crimp and F1960 Expansion fittings. If you are looking forward to offering PEX systems to new customers, this comparison will help you elaborate on the options:

PEX Installation with Crimp Fittings

PEX crimp fittings use a copper ring, insert fitting, and a PEX pipe. The copper ring sits on the end of the pipe, and the insert fitting goes into the pipe.

crimp pex fittingsThe method is specified by ASTM (F1807 – metal insert fittings and F2159 – plastic insert fittings). PEX can be installed behind the walls and is approved for direct burial within concrete and soil outdoors.

PEX crimp fittings are an easy, fast, and comparatively inexpensive method of installation. The tools used for PEX fittings are readily available in the market. However, you would need to buy the right tools according to the PEX types and sizes.

Pros of Crimp Fittings

  • Highly heat resistant
  • More flexible than expansion fittings
  • Have the highest degree of cross-linking, which makes the strongest chemical bond
  • Restricted flow of water lowers the bursting pressure
  • Easy kink fixes if the pipe is damaged or broken
  • Cheaper pipes and installation

Cons of Crimp Fittings

  • Strong shape memory makes it inflexible to fit in most spaces, leading to leaks if a crimp is loose or not installed properly
  • The smaller internal diameter of the PEX pipe restricts water flow and leads to intense pressure drop
  • Requires upsizing to increase the water flow of the distribution
  • Requires special tools like go/no go gauge according to the pipe sizes and fittings


PEX Installation with Expansion Fittings

expansion pexPEX expansion fittings also referred to as “cold expansion”, uses the expansion methods for connecting PEX tubing and fittings. The method advised by ASTM (F1960 standard specification) – uses a PEX expansion ring with a larger diameter pipe. An outer plastic sleeve is overlapped at the end of the pipe, expanded to insert a fitting.

This fitting system aids in stronger bonds by creating a water-tight seal. It makes the fittings stronger over time, which is due to its amazing shape memory.

Pros of Expansion Fittings

  • Easy to learn
  • Faster and easier installation
  • Impossible to result in dry fits
  • It offers the greatest flow without any pressure drops
  • Reduces the need for tool calibration
  • It doesn’t require complex tools
  • Less chemical leaching
  • Better resistant to oxidation
  • No corrosion
  • Installation approved for direct burial in soil, within concrete, and behind walls

Cons of Expansion Fittings

  • This method has a better flow, which leads to a higher bursting pressure if the fitting is not right
  • Complex kink fixing if damaged or broken from anywhere; you would need to replace the entire pipe and connection
  • The fitting takes longer to install in colder weather that goes below 40 degrees Fahrenheit
  • Requires a heat gun or any other tool to heat the pipe and ring for a solid connection
  • Expensive pipe and installations


Crimp or Expansion – The Verdict

PEX crimp equipment is a lot more affordable than the expansion kits. However, despite the pricing and form shortcomings, most plumbers prefer to work with expansion because installation is more efficient. There are fewer leaks, and it also seems to be more durable against extreme colds and frozen pipes, etc. Some plumbers attribute this to the fact that the inside of the fittings is a bit wider, so you get less friction during installation and usage.
Either way, you shouldn’t have issues with restricted flow; that’s pretty much a guarantee.

To make your PEX water systems run smoothly and flawlessly, always install with the manufacturer’s recommended tools, and always use a PEX cutter for cutting PEX tubing.

As a professional in the plumbing industry, you are familiar with plumbing tools, products, and devices that can help you provide the best possible services to your clients.

But thanks to the growing popularity of PEX works, more people are demanding this solution. Hopefully, we’ve given you the information you need to begin choosing the right PEX system for your business.

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