Plumbing Question

[RK1]

I was reading that one pvc 90 equates to four foot of pipe. I am getting ready to re plumb my 135 gallon reef tank. I wanted to know if that was true. If it is I am going to look at plumbing in a whole new way. I currently use hard PVC pipe. I was also currious is it better to go straight up or to angle the pipe. Any places I can find info about plumbing a tank would also be appriciated.

Thanks

Ron

 

[hquintanilla]

I´m not so sure about this...but it seems to much. Try getting this book "Aquatic Systems Engineering : Devices and How They Function" from Escobal. http://www.amazon.com/exec/obidos/ASIN/1888381108/qid=1017988106/sr=1-1/ref=sr_1_1/103-7802619-8823833
It´s a great book, and there has a section with loss factors on several fitting and clear examples of typical situations in a single or multiple tank setup.
Regards....

 

[dobish]

RK1:
I pulled out my fluid mechanics book (how I hated that class!!).....and the formula for head loss is:
head loss = K(V^2/2g)
The factor K = 1.5 for a typical 90 degree fitting and .4 for a typical 45 degree fitting.
The V^2 portion of the formula means that the head loss is proportional to the square of the velocity of the fluid through the pipe, therefore, the higher the velocity of the fluid in the pipe, the higher the head loss will be due to the fitting by the square of the velocity....

Because of this formula, I would say there is no real rule of thumb for equating types of fittings to a certain head loss in the pipe. I can tell you to use the largest diameter pipe possible when plumbing -- this will allow for the lowest velocity in the pipe which, in turn, means the lowest head losses due to friction and turbulence...
I hope this helps....I know it doesn't clear things up for you, but hopefully it will help you with the concepts.

[ April 05, 2002: Message edited by: dobish ]</p>

 

[Enkidu]

If I were you I'd use the search feature to look for posts relating to plumbing. A standard 90 degree bend is rumored to be the same as one foot of head (one foot of vertical distance). If you use more gentle bends or multiple 45 degree bends then the head loss is much less.

Happy hunting!