plumbing question

[saltyESQ]

I have 2 overflow drains, the holes are 3inches wide. what size bulk head should I purchase?

I also have a 2.5inch hole for a closed loop, how large of a bulkhead should I buy? I talked to a lfs and they said 1.5, is there anyway to get it up to 2" because I am plumbing it to a dart.

 

[dattack]

Usually 2" bulkheads for a 3" hole.
Your fish store is correct.

 

[rykwong]

I thought someone answered this question already?

 

[saltyESQ]

im still lost on yonkers.
Especially since I measured the old bulkhead for the 2.5inch closed loop drain and the inside of the hole drain is 2inch.

 

[phatphisher]

check marine depot plumbing supplies and it'll tell you the appropriate hole size for each bulkhead.

yes you can enlarge an existing hole if your tank is acrylic. not sure about glass. just use two hole saws one on top of the other. screw in your first hole saw to the arbor. this hole saw must fit semi snug inside the hole. this will be your guide and keep the hole saw from sliding all over the place since you cannot use the arbor as a guide.

screw in the second hole saw to the arbor. this will be the desired hole size. lock it into place and you are good to go.

 

[ReefMeister2]

YES, there is a way to obtain the same capacity of 2" pipe from a 1-1/2" bulkhead (no need to drill the hole larger)

YGPM

 

[saltyESQ]

my closed loop hole is a little over 2.5". The tank is glass, so I cant drill. I am looking at the old bulkhead, which needs replacement, and it measures 2"inches across on the intake hole and appears the same size throughout the entire bulkhead. This bulkhead is ideal bc then I can plumbit to a dart, but I can't find anyone who sells this bulkhead, on all the bulkheads that I have found a 2-2.5" hole will have a 1.5inch bulkhead.

and the old bulkhead does not feel cheap either.

 

[phatphisher]

YES, there is a way to obtain the same capacity of 2" pipe from a 1-1/2" bulkhead (no need to drill the hole larger)

i'm curious. please do share.

 

[ReefMeister2]

Mannnn! If I give away all my secrets then NO ONE will bother to hire me

OK, Ok, here it is:
A "standard" 1-1/2" bulkhead fitting is designed to accomodate a 1-1/2" pipe, yes?
The "outside" diameter of 1-1/2" PVC pipe actually measures 1-7/8", so guess what? the hole of a 1-1/2" bulkhead fitting actually measures 1-7/8" to accomodate this pipe. (go ahead...go grab one and measure it to see what I mean)

Sooooo....
If you take a standard 1-1/2" slip x slip bulkhead fitting and thread your fittings (ball valve, union, etc) to the OUTSIDE of the bulkhead using 2" parts ....mission accomplished! All the rest of the plumbing should be 2" from then on.
Most people just don't think to use those outside threads. As long as you use teflon tape you are good to go.

btw:
the 1/8" loss within the bulkhead fitting is extremely insignificant and not even worth mentioning....remember that it is only 3" long and way too small of a "choke" to even worry about.

Reefmeister out

 

[dpstrand]

but what about the other side that is a female slip and will only fit 1.5" pvc?

 

[ReefMeister2]

<a href=showthread.php?s=&postid=8170836#post8170836 target=_blank>Originally posted</a> by dpstrand
but what about the other side that is a female slip and will only fit 1.5" pvc?

Yes, sorry about that....that is a very legitimate question:

Generally this method is used for "drain" applications; where nothing but a stainer of some sort is needed on the other end.
So what I do is find a large basket strainer (irrigation isle at HD or Lowe's) and modify it to attach to the "outside" of the bulkhead flange (the very widest part of the bulkhead).
Many times these strainers are green (designed for lawn/runoff drains) but that is Ok in a sump. They work awesome.

An alternative method is to use 1-1/2" sch 20 PVC (thinner-walled than regular sch 40 PVC) and use a very small length of it to attach another device. But I do this only as a last resort since it reduces/chokes your "hole" down to 1-3/4". Again, the extremely short length of the stub will not significantly reduce flow as long as the rest of the components are 2"