External Pump Question

[mx mr bean]

I just finished building my new sump/ fuge and decided to run a blueline hd-x 40 externally. I have the bulkhead drilled to where the pump needs to sit on a piece of 1/2" ply wood with a 1/4" of some other material to absorb the vibrations on top of the ply wood. Any suggestions? i was looking at fiber board but had concerns about drilling into a pice so thin.

 

[scsinet]

Why not use those little rubber pads they sell for cabinet door shock absorbers?

 

[mx mr bean]

what do you think of the sheets that are used to make rubber gaskets? also i was just talking to my LFS guy and he said that i honestly dont even need a sheet of ply wood underneath. do they make rubber sheets in 3/4"?

 

[scsinet]

No, but it need not be that thick anyway.
You don't NEED a piece of plywood, but that's how I mount mine.
Here is how I do it.
I mount the pump to the plywood with a rubber washer between the pump and the plywood, and another between the pump and the screw head.
Then I use either adhesive or screw on rubber feet on the bottom of the plywood.
Rubber washers are cheap, you can get a pack of assorted sizes at Lowes for about $5.
I advise you use stainless steel screws. Those are best bought at Home Depot, as they sell 100 packs. Lowes you have to buy them in the little bags of 2 to 5, making them hideously expensive (unless you only NEED 2-5).
The plywood is also best painted to resist rot.
Of course you could use regular steel screws and skip the painting, it just doesn't look as pretty after a while.

 

[mx mr bean]

I like that idea, Thanks for the detailed response. Ill set that up tomorrow but i also was wondering what to do in the bulkhead area. I know not to thread anything onto it so should i glue a piece of straight PVC into the builkheads and then run the elbow a couple inches below that straight piece?

 

[scsinet]

Originally Posted by mx Mr Bean
http:///forum/post/3038705
I like that idea, Thanks for the detailed response. Ill set that up tomorrow but i also was wondering what to do in the bulkhead area. I know not to thread anything onto it so should i glue a piece of straight PVC into the builkheads and then run the elbow a couple inches below that straight piece?
I don't understand what you are saying, but why wouldn't you thread anything?

 

[mx mr bean]

I meant the builkead itself, I heard somewhere that its not good to thread pipe to the outside of bulkheads. My LFS said to just glue a piece of pvc pipe, straight in. Another problem arose today while i was working on the plumping from the sump to the return pump. There was a small leak coming out of the bottom of the bulkhead so i decided to silicon the edges of the bulkhead inside the sump. Was that a good idea to stop the leak? either way i have it sitting out to dry for another several hours so i have time to try something else.

 

[natclanwy]

There is no issue with threading pvc on the outside of a bulkhead.
If your bulkhead is leaking either there is an issue with your gasket or it isn't tight enough. They should not leak if properly installed, some issues with gasket could be a folded, tore, or wrinkled gasket or the gasket is not in the right place it should be between the flange and the glass if you have it on the nut side it isn't right.

 

[scsinet]

While there is nothing wrong with threading a fitting to the outside of a bulkhead, I wish you luck in finding a fitting that fits it. It's not a standard thread.

 

[natclanwy]

SCSI, all of the bulkheads I have used have had standard NPSM on the outside, are there fittings out there that are not? You can thread NPT over an NPSM fitting (both have the same thread pitch just one is tapered and one is not) you just need to be sure and use a pipe sealant because teflon tape will not seal the gap when you combine NPSM and NPT fittings and for the low pressures involved in our aquariums the seal will be plenty.
Most of the bulkheads I have used have a leftover seam down the threads that can make it difficult to thread the fittings on but if you use a triangle file to remove the seam the fittings will go on fine.

 

[scsinet]

Originally Posted by natclanwy
http:///forum/post/3039908
SCSI, all of the bulkheads I have used have had standard NPSM on the outside, are there fittings out there that are not? You can thread NPT over an NPSM fitting (both have the same thread pitch just one is tapered and one is not) you just need to be sure and use a pipe sealant because teflon tape will not seal the gap when you combine NPSM and NPT fittings and for the low pressures involved in our aquariums the seal will be plenty.
Most of the bulkheads I have used have a leftover seam down the threads that can make it difficult to thread the fittings on but if you use a triangle file to remove the seam the fittings will go on fine.
If that's the case, then sweet... I've never found a fitting that fits, but if you say that there are fittings out there, then that's good enough for me. I'll keep my eye open for them the fittings the next time I need to thread to the outside for one reason or another.

 

[natclanwy]

They are tight, mainly because of the seam I mentioned but you can usually check by threading the bulkhead nut over another male pipe fitting if the nut threads on the thread pitch is the same and you can combine the two fittings.