Plumbing questions

[Scrandrew]

I am starting a new reef and am just about to begin the plumbing. I have been doing reading and want to minimize the water flow impedence. Accordingly, I am asking for suggestions. Does flex pvc offer less resistance than rigid pvc. What I mean is, would a swooped curve offer lest water resistance than say elbows in a rigid pvc setting? Any other general thoughts to share before I begin?

A~

[mope54]

Yes, flex will be less restrictive than an elbow.
Also, a 45 will be less restrictive than a 90 degree elbow.

[Scrandrew]

The Sprung book states that two 45 degrees are more restrictive than one 90 degree elbow. Does this really make sense?

A~

[mope54]

Not to me, but one 45 is less restrictive than one 90
I have a feeling it has to do with the molding of the plastic and differences of hole bore or something along those lines that would make more fittings more restrictive regardless of shape...but that's just a hunch.

[LiquidShaneo]

One program you may want to check out is:

http://code.google.com/p/plumbingpy/

There's a windows installer along w/a howto article on using the program.

Shane

[kgross]

My first suggestion to you, is if you are worried about the friction loss, rather than worry about a flex curve verses a normal 90 elbow. Just upsize the plumbing. If you think you need 3/4 inch plumbing, use 1 1/4 and then it really will not matter how many elbows you put on it, you will still get more flow than the straight 3/4 pipe.

Just to give you some solid examples of what I am talking about. Using the Head loss calculator here on RC. Take a gen x mak4 with 3/4 inch pipe, 4 feet horizontal 4 feet vertical and 3 elbows. aprox 890 gph, move to 1 1/4 pipe and use 9 elbows and you get 1028 gph.

What I use to size my pipe, up to 500 gph 1 inch 500 to 1000 1 1/4, 1000 to 1500 1 1/2 over 1500 use 2 inch. Then you can put as many elbows on it as you need without worrying about the head loss. Also when possible use thin wall pipe over schedual 80 because the size of the pipe determines the OD, and with a thinner wall you get a much larger ID so you get more flow.

Kim

[ludnix]

I have a somewhat related question.

How can I connect a mag5 pump to PVC? I'm using 3/4" PVC and the outlet on the mag5 seems to 1/2". I'm not sure what would be the best way to go about this.

[flyyyguy]

put a 3/4" x 1/2" FPT reducing bushing in a 3/4" fitting and screw it on the pump. Or if you want to save some flow.....use 1" instead of 3/4" pipe. Same thing...reduce it down to a 1/2" FPT

[ambaratur]

I used some of the grey PVC conduit at Home Depot that has the nice rounded corners. Below is a picture - it is not the best shot but I think you can see the rounded corners in the grey PVC.

[Scrandrew]

Is the conduit pipe able to withstand the pressure of the water? What sort of plumbing glue do you use with the conduit?

A~

[flyyyguy]

conduit uses the same glue/primer and can handle the pressures we use no problem if glued right

Flex pvc is a better option though IMO