Looking for caculator for bulkhead size

[allincuddy]

I had one on some place on the internet, punch in the size of bulkhead and it would tell you how many gallons (capacity) it would do. Now I must have deleted it and need to do a calculation.
I have a 7/8" ID on a 65 and wondered if that would give me 3 turn overs or 195 gal. per hour??
If anyone can help, I would appreciate it.
Thanks.

[christyf5]

http://www.reefcentral.com/calc/drain.php

[allincuddy]

Thank you, exactly what I was looking for.
Thanks again.

[TheReefGeek]

That calculator looks a little dangerous.

Is it assuming there is pressure on top of the bulkhead or not?

[G1GY]

That calculator looks a little dangerous.

Is it assuming there is pressure on top of the bulkhead or not?

It's for drains. So that would probably mean "free flowing".

[allincuddy]

Well I have a 7/8 inch bulkhead on a 65 gallon tank andit says that size will do 440 gal/hr so that is amax. of 8 turn overs, should be good to go.3 tun overson afrag tank should be good?????
Thanks.

[Samw]

What is linear overflow size? It says that I need 5" for a 300GPH flow.

[mark]

What is linear overflow size? It says that I need 5" for a 300GPH flow.

total measurement of overflow tower (wier).

[Samw]

So this is the height from the top of overflow to the top of the waterline of the sump right?

[TheReefGeek]

No, the linear measurement means how long of a distance the water can flow over.

Imagine a waterfall. It is 10 meters across. This is the type of measurement you want.

Now for your overflow, say you have a standard corner overflow, you have two lengths you have to add up for the total linear measurement.

It's for drains. So that would probably mean "free flowing".

"Probably" is not a good term in plumging a reef. :mrgreen: Leads to too many floods. That is why this calculator is dangerous. Good as a gernal guide though, a starting point better than nothing.

If you have 20 inches of water in your overflow pushing down on the drain, it is going to flow faster than if you have 5 inches of pressure.

Also you can get some suction/siphoning going, but that is not recommended.

[Static]

Well I have a 7/8 inch bulkhead on a 65 gallon tank andit says that size will do 440 gal/hr so that is amax. of 8 turn overs, should be good to go.3 tun overson afrag tank should be good?????
Thanks.


Do they make a 7/8" bulkhead? I've never seen any 7/8" pipe. I'm tempted to think you have a 1/2" bulkhead. Is it slip fit or female pipe threads? Remember the size of the bulkhead is actually determined by the pipe that slides/threads into it. And it's the hole inside the pip that's measured, not the outside diameter of the pipe.

[G1GY]

"Probably" is not a good term in plumging a reef. :mrgreen: Leads to too many floods. That is why this calculator is dangerous.

In your first post in this thread you asked:
Is it assuming there is pressure on top of the bulkhead or not?
The correct response from me should have been:
Hell no! There is no pressure on a drain bulkhead! Only the weight of any water that is on top of it.(Weight and pressure are two totaly different things.)

My reply with the word "probably" was just a nice way of saying "No pressure....... Only weight."

BTW, there's nothing wrong with this calculator IMO. :)

[TheReefGeek]

Ok, so does the calculator assume there is no weight for the flow rates it spits out then?

I am not a physics expert, sorry if I used the wrong terms.

In my basic knowledge of physics, isn't one of Newton's first laws f = m * a, or force = mass times acceleration? Force is aptly named as N, for Newtons.
And water having mass, being pulled down by gravity at 9.81? m/s squared, will create force. That force when partially blocked at a bulkhead would create pressure, pressure expressed as Newtons per square inch? Maybe there is no pressure right at the bulkhead, just the surrounding glass?

I'm not sure, I just think you can put more through a bulkhead where there is more water sitting on top of the bulkhead than if there is none?