I have found all of the information on the Internet that I need for calculating head loss at different flow rates through different diameters of PEX, PEX-AL-PEX, and copper and I have found tables which show pipe length equivalents for a variety of copper fitting and valves, but I can't seem to find data for PEX and PEX-AL-PEX fittings. Does anyone know where to find pipe length equivalents or K values for PEX and PEX-AL-PEX fittings?
The PEX-AL-PEX compression fittings in particular appear to have a very small I.D., relative to the pipe size. I wonder whether a 1" Uponor ProPEX expansion fitting has as big of an I.D. as a 1" PEX-AL-PEX fitting?
I am going to have about a 60' underground PEX run and need to pass up 40K BTUs/hour through that underground loop. Using regular O2 barrier PEX for the underground runs and adding the pipe length equivalents for all of the 1-1/4" and 1" copper, black pipe, valves, and fittings (but not PEX fittings), gives me the following points the Grundfos 15-58 pump curves:
12.7' head @ 6.4 gpm (high setting)
10.1' head @ 5.6 gpm (medium setting)
5.8' head @ 4.1 gpm (low setting)
That seems perfectly adequate for my heat load, but should I be concerned with the head loss due to the PEX fittings? I have a Watts crimp tool for the Oetiker style SS ear rings, I can rent a ProPex expansion tool (for up to 1") for $25 per day, or I can use compression fittings. 1-1/4" PEX seems like overkill for my application and the far greater cost of 1-1/4" PEX, fittings, and tools makes it seem like a poor choice. Moving up to larger I.D. 1" PEX-AL-PEX certainly would seem to compensate for its rather restrictive fittings.
One more question, Do ordinary PEX-AL-PEX compression fittings work with Uponor MultiCor (MLC) PEX-AL-PEX, or do you need to use the Uponor fittings which I think require a $3000 tool when you get up to the 1" size?
Pete Schiller
The PEX-AL-PEX compression fittings in particular appear to have a very small I.D., relative to the pipe size. I wonder whether a 1" Uponor ProPEX expansion fitting has as big of an I.D. as a 1" PEX-AL-PEX fitting?
I am going to have about a 60' underground PEX run and need to pass up 40K BTUs/hour through that underground loop. Using regular O2 barrier PEX for the underground runs and adding the pipe length equivalents for all of the 1-1/4" and 1" copper, black pipe, valves, and fittings (but not PEX fittings), gives me the following points the Grundfos 15-58 pump curves:
12.7' head @ 6.4 gpm (high setting)
10.1' head @ 5.6 gpm (medium setting)
5.8' head @ 4.1 gpm (low setting)
That seems perfectly adequate for my heat load, but should I be concerned with the head loss due to the PEX fittings? I have a Watts crimp tool for the Oetiker style SS ear rings, I can rent a ProPex expansion tool (for up to 1") for $25 per day, or I can use compression fittings. 1-1/4" PEX seems like overkill for my application and the far greater cost of 1-1/4" PEX, fittings, and tools makes it seem like a poor choice. Moving up to larger I.D. 1" PEX-AL-PEX certainly would seem to compensate for its rather restrictive fittings.
One more question, Do ordinary PEX-AL-PEX compression fittings work with Uponor MultiCor (MLC) PEX-AL-PEX, or do you need to use the Uponor fittings which I think require a $3000 tool when you get up to the 1" size?
Pete Schiller
