insulated underground piping, which ones are better

[muleman51]

My underground piping has developed a leak to the tune of close to ten gallons some weeks. Besides wasting water it wastes a lot of heat. My original piping is one inch pex in a foam box wrapped in plastic. I'm sure its been in close to twenty years although that isn't saying much my plastic water lines from my well are over 50. I see foam filled lines and 3 wrap and 5 wrap lies which ones do you recommend. I am sru I could find the leak but will the foam in the old lines dry out enough to not lose heat. Or am I just better off replacing all125 feet. molets face it wood burning is an addiction it really doesn't save us any ROI, but it can be fun. Thanks Jim

 

[maple1]

Have you checked out the 'undergound piping' sticky at the top of the forum?

You could go either spray-in-trench-foam as discussed there, or Thermopex or Logstor or the very like.

Whatever you do, it should involve closed cell foam insulation around the piping. I would get rid of what you have, and stay away from the layered wrapped stuff. I might also consider upping to 1-1/4" while at it, that would lighten the pumping load considerable over your 125 feet.

 

[woodsmaster]

Id agree with maple 1 on the type of line. as far as size, that depends on you btu/hr and delta T. Just have to do the math and see if its worth bigger line and smaller pump.

 

[ewdudley]

Here's some flow for 1.000 and 1.250 inch (nominal) PEX with various pumps at various speeds. Line length is set to 300 ft length equivalent, which assumes the line is 125 ft one way/250 ft round-trip, plus a dozen or so fittings at 4 ft length equivalent each. The same pump can appear at different speeds. Not all speeds are shown, but at least the highest speed appears if any speed does.

pipe          d length  psi    head  gpm  pump
PEX_1.000 0.863    300  1.18   2.72  2.26  Grundfos_15-55-Alpha-I
PEX_1.000 0.863    300  1.70   3.93  2.75  B&G_Vario-II
PEX_1.000 0.863    300  3.01   6.94  3.74  Grundfos_15-55-Alpha-II
PEX_1.000 0.863    300  3.01   6.95  3.75  Grundfos_15-58-I
PEX_1.000 0.863    300  3.91   9.03  4.31  Taco_007
PEX_1.000 0.863    300  4.64  10.71  4.73  B&G_Vario-IV
PEX_1.000 0.863    300  4.86  11.22  4.85  Grundfos_15-58-II
PEX_1.000 0.863    300  5.65  13.02  5.26  Taco_008
PEX_1.000 0.863    300  5.81  13.39  5.34  Grundfos_15-55-Alpha-III
PEX_1.000 0.863    300  6.02  13.89  5.44  Grundfos_15-58-III
PEX_1.000 0.863    300  6.97  16.08  5.89  B&G_Vario-VII
PEX_1.000 0.863    300  9.80  22.61  7.08  Grundfos_43-75

pipe          d length  psi    head  gpm  pump
PEX_1.250 1.053    300  1.07   2.47  3.61  Grundfos_15-55-Alpha-I
PEX_1.250 1.053    300  1.25   2.88  3.93  B&G_Vario-II
PEX_1.250 1.053    300  2.10   4.83  5.19  Grundfos_15-58-I
PEX_1.250 1.053    300  2.73   6.30  5.99  Grundfos_15-55-Alpha-II
PEX_1.250 1.053    300  3.37   7.77  6.71  B&G_Vario-IV
PEX_1.250 1.053    300  3.60   8.31  6.96  Taco_007
PEX_1.250 1.053    300  3.62   8.35  6.98  Grundfos_15-58-II
PEX_1.250 1.053    300  4.54  10.47  7.89  Taco_008
PEX_1.250 1.053    300  4.68  10.79  8.01  Grundfos_15-55-Alpha-III
PEX_1.250 1.053    300  4.76  10.97  8.09  Grundfos_15-58-III
PEX_1.250 1.053    300  5.31  12.26  8.59  B&G_Vario-VII
PEX_1.250 1.053    300  8.95  20.65 11.38  Grundfos_43-75