ok so once again i am doing over my plumbing for my tank. now my main question is schedule 40 vs schedule 80, what are your guys opinions??????? now my second question is painting pvc. i want to match up the color to the color of my pump, so basically what type of paint would be best?
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plumbing questions
- Thread starter jpnasty
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newenglandreef
Non-member
You'll need more pump power w Sch 80 due to increased head pressure.
Why would thicker pipe wall increase head prssure?
While its true that the inside diameter if schedule 80 pipe is SLIGHTLY smaller due to the thicker wall, you are not going to need a larger pump unless you are going very long distances with lots of turns.
but i just want my piping to match the yellow of the pan world pump im gonna useIt increases friction loss because the thicker walls mean that the ID is smaller.
That is negligible,John.
And there's also less water wieght to be pushed up.
Yes,use sch. 40 by all means.
Actually it may not be so negilgible Bob. While it is a small difference in ID size with a large pipe such as 3" or 4", it is a pretty big difference with the sizes we tend to be using such as 1". Also IIRC the logic about pushing less weight of water doesn't apply as much as one might think. I don't understand the fluid dynamics in depth, but I can say that it's more about the amount of water the pump is actually pumping at any given time than it is about the total weight of the water in the pipe.
I'll go looking for some references or at least a pic of the actual difference between the ID of Sch40 vs Sch80 later, but work needs me at the moment...
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newenglandreef
Non-member
some disagree with you. In fact, there are charts that calculate pump requirements, which differ between Schedule 40 and Schedule 80.
newenglandreef
Non-member
The Reef Aquarium Volume 3 discusses it in detail John.
Look at the book again, at 1" pipe its not that big of a deal unless you start running at high volumes. 5 feet of 1" schedule 40 pipe running at 600gph gives you 0.3 feet of frictional head loss due to the pipe. 5 feet of 1" schedule 80 pipe running at 600gph gives you 0.5 feet of frictional head loss. That's a difference of 0.2 feet or 2.4 inches in head height per 5 foot lengths of pipe. That's not going to make a huge difference with most pumps in a typical in the cabinet sump with a typical flow rate. Decreasing pipe size or increasing volume could have a big effect, especially if you are going for long runs of pipe or lots of fittings, like I already said before.
Even if hes got a basement sump, which still at 20 feet of pipe only add about 10" in head height over schedule 40, I really don't think its that big of a deal.
Even if hes got a basement sump, which still at 20 feet of pipe only add about 10" in head height over schedule 40, I really don't think its that big of a deal.
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When I start to worry about the difference .092 id. between sch 40 and 80 of 1 inch PVC,then it will indeed be time for me to retire from this hobby.
I see no reason to use something(Sch 80)that's rated for 2000 psi for return line.The 1500 psi rated sch. 40 is fine.
I see no reason to use something(Sch 80)that's rated for 2000 psi for return line.The 1500 psi rated sch. 40 is fine.
newenglandreef
Non-member
I think there is a greater differential at higher GPH (and lower ID). What are the numbers for 900 GPH?
It just needs to be taken into consideration when planning a system based on your flow and turnover requirements. But in my view, why place greater burden on your return than necessary without any real benefit?
Misfit, thks for looking up those numbers.
I think we all agree that it's not a giant difference, but it is a difference and IMO shouldn't be dismissed outright as non existent. In many applications it may not matter, but it certainly could in some builds.
Beyond any hair splitting, as Bob said, there is no reason to spend extra $ to use heavy duty pipe meant for high pressure in our systems. I'm pretty sure we all agree on that.
I think we all agree that it's not a giant difference, but it is a difference and IMO shouldn't be dismissed outright as non existent. In many applications it may not matter, but it certainly could in some builds.
Beyond any hair splitting, as Bob said, there is no reason to spend extra $ to use heavy duty pipe meant for high pressure in our systems. I'm pretty sure we all agree on that.
newenglandreef
Non-member
Looked up 900 GPH...just for reference, a 1 inch pipe at 900 GPH Sch. 80 is .20 feet of friction head per foot; Sch 40 is .03 (actually less than 600 GPH), then at 1200 GPH (same 1 inch pipe), Sch. 80 is .35; Sch 40 is .06. So five feet at 900 GPH would be nearly a foot of friction loss over the Sch. 40. At 1200 GPH, friction loss at 5 feet would be about a foot and a half.
