What is the maximum safe temperature for PEX tube?
Some people think that the PEX-a, pex-b, and rex-c designation are a description of performance for the tubing.The manufacturing processes which have been developed over the years are what the designation is for.
The earliest method of cross-linking PEX tubing was the Peroxide Method, which was developed in Europe in the 1960s.The method uses organic peroxides that cause free radicals when heated.The process is sometimes referred to as the PEX-a Process.ThePPI is a plastic pipe institute.
The Silane method is one of the most widely used methods for manufacturing PEX tubing.The method involves attaching a molecule to the polyethylene.The process is sometimes referred to as the PEX-b Process.It's called PPI.
The "clean" method for cross-linking PEX tubing is the electron beam method.The PE pipe is subject to a dose of high-energy electrons.The process is sometimes referred to as the PEX-c Process.It's called PPI.
The flexibility of PEX comes at a loss of chlorine resistance and lower burst pressures, which is a detraction of each method.At a loss of flexibility, PEX-b has the highest chorine resistance and burst pressures.PEX-c has a clean composition, but it does stand out as being more durable and resistant to chlorine.
Plumbing Systems & Design Magazine June 2008 has more information on the book: http://plasticpipe.org/publications/pex_handbook.html.
A material that won't break down is the result of cross-linking.It is a good material for drinking water bottles because it is cheap and can be recycled.It is not very good as a building material because it breaks down quickly.It will be able to handle higher temperatures thanks to cross-linking.So higher cross-linking is better?Not much.
The manufacturer has to either create the siloxane bridge or add free radicals.The manufacturer adds enough "free radicals" such that when they are used up the tubing should reach the desired cross-linked level, or as in the PEX-b method.It's hard to get a completely cross-linked tubing.As cross-linking increases, the tubing becomes more brittle.
The level of cross-linking is determined by the performance characteristics desired.Cross-linking amounts are not a measure of performance.
Is the tubing listed by diameter?The industry standard is to list tubing by it'sNominal ID.Some manufactures list their products by diameter.You need to compare the same size tubing.The PEX tubing sizing system is called SDR-9.If you are selecting a fitting or tubing make sure it is SDR-9 compliant.
What is the application?We always want to choose the smallest diameter tubing for the application.If we are carrying hot or cold water from one point to another, our only concern is to be able to deliver enough volume and pressure at the other end of the pipe.If you need more flow or more pressure, a large diameter tubing will help.We have more to consider if our use is for heat transfer.
We need to make sure we deliver enough heat for the load demand in heating applications.Larger tubing should give us more heat transfer because it's at the surface of the tubing.The RPPA recommends a minimum bend radius of 8 times the ID of the tubing, if we need to consider tubing spacing in a radiant floor heating installation.1/2 in tubing has a minimum spacing of 8 in on center and a maximum of 5 in bend radius.There is tubing spacing.radiantprofessionalsalliance.org
We will have 20% less tubing if we install it on minimum spacing.The tubing was installed less than 1/2 in.There is tubing.5/8 in tubing has 10% more surface area than 1/2 in.The tubing is 2.355 in..625 X is 2.12When installing minimum tubing spacings in a radiant floor install, a larger diameter pipe can cause a NET loss of surface area or heat transfer.
The heat carrying capacity of water is so high that it's more than enough for most radiant floor heating applications.Let a qualified professional do the math for you.
If you want to distribute hot water to a shower, faucet or other fixture, you need to consider how long it will take to get cold water out of the line.The 1/2 in supply line has less water than the 5/8 in line.There will be more water in the line.When you increase the tubing diameter, you will experience a 50% to 100% increase in time or wasted water when turning on a faucet.This is 3/8 in.Half as much water is carried by tubing.Will respond twice as fast.
The pressure rating for PEX tubing is F877.The operating pressure drops as the temperature increases.
All PEX tubing needs to conform to the standards of the American Society for Testing and Materials.The majority of PEX tubings exceed those standards.They stop their similarities there.
This is the most important factor in choosing a tubing product.Property damage due to a failure is probably not covered by the warranty.Will it cover labor and parts if there is a manufacturing defect?Some give you more tubing.
Is your installation covered by the manufacturers defect?If the product was installed by a trained professional, it will be covered by the manufacturer's warranty.Before you buy, check the fine print.
You might say that you don't have a warranty claim.You can bet that a manufacturer will do more to maintain the quality of their product if they write a more open warranty.
When asking a crew of pipe fitters to drag your PEX pipe across some rebar and then let the masons bury it in concrete while using shovels and rakes and implements of destruction, you might want to put your hands on the most durable tubing you can get.A good indicator of a durable tubing is high burst pressure.It is more rigid than other brands in the same price point.