What is PEX Tubing?
Plain-English explanation from a licensed Utah HVAC, plumbing, and electrical contractor.
PEX is a cross-linked polyethylene plastic pipe used for residential water supply lines — it's flexible, freeze-resistant, easier to install than copper, and has been the dominant Utah residential plumbing material since around 2005.
Full Definition
PEX (Cross-linked Polyethylene) is a flexible plastic tubing manufactured in three molecular cross-linking methods: PEX-A (Engel method, most flexible), PEX-B (silane / Sioplas, most common), and PEX-C (electron beam, stiffest). PEX is sold in three color codes for Utah residential: red for hot, blue for cold, and white for either. Fittings are crimp-ring, cinch-clamp, or push-to-connect (SharkBite) style.
PEX is corrosion-proof, immune to mineral scale buildup from Utah's hard water, freeze-resistant (expands without bursting), and costs roughly 60% less to install than copper. Most homes built after 2005 in Utah use PEX exclusively. Lifespan estimated at 40+ years.
Common Questions
Is PEX safe for drinking water?
Yes — PEX is NSF-61 certified for potable water in all U.S. jurisdictions and has been used in European homes since the 1970s. Some homeowners notice a faint plastic taste in new installs that resolves within a few weeks.
PEX or copper for repipes?
PEX wins on cost, freeze resistance, and ease of repair. Copper wins on UV resistance and resale perception. For 99% of Utah residential repipes, PEX is the better choice.
Related Terms
Water Hardness
Water hardness is the amount of dissolved calcium and magnesium in your water, measured in grains per gallon (gpg) — most Utah cities deliver 12–28 gpg, well into the 'very hard' range.
ABS Pipe
ABS is black plastic drain-waste-vent pipe used for residential plumbing — it's solvent-welded with one-step cement, performs well for sewer and vent piping, and is the standard Utah residential DWV material under code.
Thermal Expansion Tank
A thermal expansion tank is a small bladder tank installed near the water heater that absorbs the water expansion when your heater heats cold water — preventing dangerous pressure buildup in closed plumbing systems.
Recent PLUMBING work in Utah
A few installs and service calls from the AYSP crew.
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