Plumbing 101

[Toni]

Bulkheads- what is the difference between standard threaded and double
threaded? Which one do I want on my main overflow drain?

Ball valves- I plan to use several of these where ever I think I might
possibly need them (fear of flooding)- what is the difference between
threaded, single union, and true union? Is it "no easy screw off", "one easy
screw off", and "two easy screw offs" (one on each end)?

Check valves- do I want true union, socketed swing or FPT swing?
I know these are not fool proof but should I use one on my return line just
as insurance?

I am quite sorry to be so dense- back in "my day" ladies were not taught
this stuff. If anyone could possibly recommend a website that takes this
topic down to the absolute beginner basics I could really use it.


--
Toni
http://www.cearbhaill.com/aquarium.htm
< have I exceeded my daily allotment of newbie questions yet?>

[Pszemol]

"Toni" > wrote in message ink.net...
> Check valves- do I want true union, socketed swing or FPT swing?
> I know these are not fool proof but should I use one on my return
> line just as insurance?

I am not plumber myself so I skept previous questions and refer
only to the part quoted above - you do not need any check valves
on your return line. The problem you want to solve with syphoning
water from the tank by the submerged end of your return line is
very easy to solve by drilling very small hole (or 2) in the return
line inside the tank at, or just above the normal water level...
This way, when the return pump stops pushing water up, the syphon
will break with the air going into the return line through the hole.
It is much safer than a check valve, cheaper and simpler as well :-)

[Marc Levenson]

Toni, read below...

Toni wrote:

> Bulkheads- what is the difference between standard threaded and double
> threaded? Which one do I want on my main overflow drain?

Standard threaded will have the threads in the top end only, and (inside) slip
connection in the other end.
Double threaded will allow you to screw something into either end.

Either will work, to be honest, so it is just a matter of how you want to
assemble the puzzle. If you do go with a slip bulkhead fitting, when you glue
in the drain pipe, be sure to leave enough (6" or more) so if you ever have to
cut the pipe, you can still have some pipe to glue a new fitting to when
re-plumbing. It happens. ;)

> Ball valves- I plan to use several of these where ever I think I might
> possibly need them (fear of flooding)- what is the difference between
> threaded, single union, and true union? Is it "no easy screw off", "one easy
> screw off", and "two easy screw offs" (one on each end)?

Ball valves are useful ONLY when you need to turn off the flow. Typically,
you'll need to do that once or twice a year. To see what some fitting look
like, take a look at this page because I have some images on there.

http://www.melevsreef.com/how_to_build.html

A threaded union is a great way to remove a pump from your existing plumbing
easily.

> Check valves- do I want true union, socketed swing or FPT swing?
> I know these are not fool proof but should I use one on my return line just
> as insurance?

I don't use them. Drill *two* small holes in your return line (where the water
pours back into the display tank) 1/2" *beneath the water's surface.* This will
only allow 1/2" of water to drain to the sump, and doesn't introduce
microbubbles into your display when the pump is running. These are called
"anti-siphon holes". The reason you drill two is because one may clog or even
have a snail parked on it at the very moment you need it to work.

> I am quite sorry to be so dense- back in "my day" ladies were not taught
> this stuff. If anyone could possibly recommend a website that takes this
> topic down to the absolute beginner basics I could really use it.
>

No problem. Ask away.

Marc


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