<h2 id="everything-you-always-wanted-to-know-about-pex">Everything You Always Wanted to Know About PEX</h2>
<h3 id="part-02--the-joy-of-pex---what-is-it-and-how-is-it-used">Part 02- The Joy of PEX - What is it and how is it used?</h3>
<ol type="1">
<li>What is PEX?
<ol type="1">
<li>According to Wikipedia, Cross-linked polyethylene tubing is commonly abbreviated PEX, XPE or XLPE -<a href="https://en.wikipedia.org/wiki/Cross-linked_polyethylene" class="uri">https://en.wikipedia.org/wiki/Cross-linked_polyethylene</a></li>
<li>This tubing is made of crosslinked polyethelene chains</li>
<li>Type A, Type B, &amp; Type C</li>
<li>These differ based on the process used to make them and the resulting properties of the resulting tubing</li>
<li>PEX is used for a variety of products</li>
<li>Insulation on high voltage high tension electrical cables</li>
<li>Domestic water pipes</li>
<li>Irrigation and hydroponic systems</li>
<li>Natural gas and oil pipes</li>
<li>Chemical handling and storage systems</li>
</ol></li>
<li>Domestic plumbing
<ol type="1">
<li>Advantages</li>
<li>Flexible &#x2013; easy to install and fish through walls and crawl spaces</li>
<li>It will stretch a little &#x2013; Less likely to rupture if water contained in PEX freezes</li>
<li>Does not rust or corrode</li>
<li>Less expensive than copper</li>
<li>Multiple colors for easy identification</li>
<li>Easy to cut</li>
<li>Connections are easy
<ol type="1">
<li>Type A &#x2013; Expansion PEX</li>
<li>Process
<ol type="1">
<li>A roughly 1/2" - 3/4"sleeve of slightly larger PEX expansion sleeve is slipped over the end of the PEX-A tubing</li>
<li>A special tool is inserted into the end of the tubing which stretches it outward a predefined amount.</li>
<li>The tubing is slipped over the end of the desired PEX-A connector and allowed to shrink back to normal size, creating a seal</li>
<li>Video: <a href="https://www.youtube.com/watch?v=Xot95W8vni0" class="uri">https://www.youtube.com/watch?v=Xot95W8vni0</a></li>
</ol></li>
<li>Advantages
<ol type="1">
<li>Fast and easy to install</li>
<li>Can install in tight places, since tool does not need to be at the connector</li>
<li>More resistant to damage from kinks if bent over too tight a radius</li>
<li>More resistant to damage from freezing</li>
</ol></li>
<li>Disadvantages
<ol type="1">
<li>The tool is expensive (~$300 - $600 USD)</li>
<li>In the United states, PEX-A connectors have limited availability in typical hardware and home improvement stores</li>
</ol></li>
<li>Type B &#x2013; Crimp PEX (Doesn't stretch)</li>
<li>Process
<ol type="1">
<li>A metal ring or band is placed around the end of the PEX-B tubing</li>
<li>The tubing is slipped over the end of the desired PEX-B connector</li>
<li>A special tool us used to crimp the metal ring or a different tool may be used to tighten the metal band, creating a seal</li>
<li>Video: <a href="https://www.youtube.com/watch?v=U-t-ZeHv9s0" class="uri">https://www.youtube.com/watch?v=U-t-ZeHv9s0</a></li>
</ol></li>
<li>Advantages
<ol type="1">
<li>Fast &amp; easy to install</li>
<li>Crimping tools are less expensive</li>
<li>Higher availability of a wider range of connectors at typical home improvement stores in the United States</li>
</ol></li>
<li>Disadvantages
<ol type="1">
<li>If PEX-B is kinked, that portion is no longer safe to use and it must be replaced.</li>
<li>Can be more difficult to connect in tight places</li>
<li>This can be remedied with the use of SharkBite press on fittings.</li>
<li>Less resistant to damage from freezing.</li>
</ol></li>
</ol></li>
<li>Connections are also easily removed</li>
<li>Disadvantages</li>
<li>Easily damaged by ultraviolet light from sunlight or even LED &amp; fluorescent lights (Check manufacturer specifications. Most rated for only 30-60 days of sun exposure)
<ol type="1">
<li><a href="https://www.doityourself.com/stry/how-long-can-pex-piping-be-exposed-to-sunlight" class="uri">https://www.doityourself.com/stry/how-long-can-pex-piping-be-exposed-to-sunlight</a></li>
<li><a href="https://www.flowguardgold.com/en-us/blog/the-influence-of-uv-light-on-plastic-plumbing-systems" class="uri">https://www.flowguardgold.com/en-us/blog/the-influence-of-uv-light-on-plastic-plumbing-systems</a></li>
</ol></li>
<li>Long term durability yet to be proven</li>
<li>Non-conductive (electrical ground)</li>
<li>Not rigid &#x2013; Must be supported</li>
<li>May induce an odd taste to water for the first few weeks.</li>
<li>Some say PEX can leach toxins into water
<ol type="1">
<li>Norwegian Institute of Public Health study says PEX is safe <a href="https://www.sciencedaily.com/releases/2011/11/111108132905.htm" class="uri">https://www.sciencedaily.com/releases/2011/11/111108132905.htm</a></li>
<li>Ewg.org article expresses doubts to safety <a href="https://www.ewg.org/news-insights/news/amid-pipe-wars-researchers-wary-plastic-pipes-leaching-chemicals" class="uri">https://www.ewg.org/news-insights/news/amid-pipe-wars-researchers-wary-plastic-pipes-leaching-chemicals</a></li>
</ol></li>
</ol></li>
</ol>
