mcarroll
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Well....depends on the diameter of plumbing...whether tubing or PVC.
Large-size tubing is pretty expensive, so most folks don't use much besides small tubing.
But in general, tubing should be close to the same as PVC as long as the inside diameter is the same on both.
(Vinyl tubing thickness isn't nearly as standard as PVC, where almost all you see is "schedule 40" thickness.)
Along with diameter of plumbing, the flow rate is what you're most concerned with.
Higher flow rates generate more internal friction. More internal friction means less space inside the pipe for smoothly flowing water.
By the same token, lower flow rates mean less internal friction. At sufficiently low flow rates plumbing size almost doesn't matter.
If I could change your mind back to hard PVC I would. The only exception is if you're keeping the flow fairly low for the size of tubing you pick – then, like I said, it doesn't usually matter so much.
If the return in question is for the 28 gallon tank on this thread, you should only need around 50GPH to 100GPH – thankfully that should be easy with almost any tubing size.
Just for example, 1/2" PVC would add nearly no friction loss at this flow rate:
You'd just have to look up the internal diameter (ID) of you tubing and compare that with the ID of Schedule 40 PVC to know how good that estimate is for tubing.
Large-size tubing is pretty expensive, so most folks don't use much besides small tubing.
But in general, tubing should be close to the same as PVC as long as the inside diameter is the same on both.
(Vinyl tubing thickness isn't nearly as standard as PVC, where almost all you see is "schedule 40" thickness.)
Along with diameter of plumbing, the flow rate is what you're most concerned with.
Higher flow rates generate more internal friction. More internal friction means less space inside the pipe for smoothly flowing water.
By the same token, lower flow rates mean less internal friction. At sufficiently low flow rates plumbing size almost doesn't matter.
If I could change your mind back to hard PVC I would. The only exception is if you're keeping the flow fairly low for the size of tubing you pick – then, like I said, it doesn't usually matter so much.
If the return in question is for the 28 gallon tank on this thread, you should only need around 50GPH to 100GPH – thankfully that should be easy with almost any tubing size.
Just for example, 1/2" PVC would add nearly no friction loss at this flow rate:
Pressure Loss (psi): 0.12 Head Loss (ft): 0.3
Line Number:
Date: 2/18/2017
Nominal Pipe Size: 0.5
Pipe Schedule: SCH 40
Flow Rate (gpm): 2
Viscosity (cP): 1
Specific Gravity (water=1): 1.025
Temperature (F): 79
Pipe Roughness (ft): 0.000016
Actual Pipe ID (in.): 0.622
Fluid Velocity (ft/sec): 2.11
Reynolds Number: 10423
Flow Region: Turbulent
Friction Factor: 0.031
Overall K: 3.93
Piping Length (ft): 4
Short Radius Elbows: 1
Pipe Exit : 1
Line Number:
Date: 2/18/2017
Nominal Pipe Size: 0.5
Pipe Schedule: SCH 40
Flow Rate (gpm): 2
Viscosity (cP): 1
Specific Gravity (water=1): 1.025
Temperature (F): 79
Pipe Roughness (ft): 0.000016
Actual Pipe ID (in.): 0.622
Fluid Velocity (ft/sec): 2.11
Reynolds Number: 10423
Flow Region: Turbulent
Friction Factor: 0.031
Overall K: 3.93
Piping Length (ft): 4
Short Radius Elbows: 1
Pipe Exit : 1
You'd just have to look up the internal diameter (ID) of you tubing and compare that with the ID of Schedule 40 PVC to know how good that estimate is for tubing.
