Folks,
I will be replacing a 20' section of 1/2" Cu that feeds external hose bibb (pinhole leaks). I am concerned about the lack of accomodation for thermal expansion of this long pipe. I looked up some formulas for expansion of copper tubing and how long pipe offset should be to accomodate expansion. (Technical Reference Guide Thermal Pipe Expansion) I figure pipe temperature can go as high as 85 degrees F (summertime, we are on vacation and have AC set warm and pipes are empty because inside value is off), and as low as 45 degrees F (winter). For a 20' pipe this would be an expansion of 0.082". This means that I need 19" between the 90 degree bend (at the end of the 20' length) and the next anchor point (according to above reference).
1 - the current plumbing has only 6 inches of length (I'm thinking I need to increase it).
2 - reading this forum as well as others there seems be a code requirement to support pipe within 12" of major change in direction. What happens if the need to accomodate expansion requires more than 12"
3 - The references also describe that on each straight section there should be a single anchor point and additional supports should be "guides" that allow pipe to slide as the pipe expands. The 20' pipe is currently anchored firmly to a joist every 6' with a strap. Since the hose bibb itself is an anchor point on outside of house, seems like all interior supports on this 20' section should allow sliding.
Am I overanalyzing this in my ignorance? Is there a more appropriate reference for this?
Thanks.
I will be replacing a 20' section of 1/2" Cu that feeds external hose bibb (pinhole leaks). I am concerned about the lack of accomodation for thermal expansion of this long pipe. I looked up some formulas for expansion of copper tubing and how long pipe offset should be to accomodate expansion. (Technical Reference Guide Thermal Pipe Expansion) I figure pipe temperature can go as high as 85 degrees F (summertime, we are on vacation and have AC set warm and pipes are empty because inside value is off), and as low as 45 degrees F (winter). For a 20' pipe this would be an expansion of 0.082". This means that I need 19" between the 90 degree bend (at the end of the 20' length) and the next anchor point (according to above reference).
1 - the current plumbing has only 6 inches of length (I'm thinking I need to increase it).
2 - reading this forum as well as others there seems be a code requirement to support pipe within 12" of major change in direction. What happens if the need to accomodate expansion requires more than 12"
3 - The references also describe that on each straight section there should be a single anchor point and additional supports should be "guides" that allow pipe to slide as the pipe expands. The 20' pipe is currently anchored firmly to a joist every 6' with a strap. Since the hose bibb itself is an anchor point on outside of house, seems like all interior supports on this 20' section should allow sliding.
Am I overanalyzing this in my ignorance? Is there a more appropriate reference for this?
Thanks.