True union between sump and pump???

[mr.maroonsalty]

How much trouble is it diconnectioning the external pump without using a union? I ran into a tight spot today; the easiest way out is to leave out the 2" union between the sump and pump. If I leave it off I would need to loosen the bulkhead nut and back out the pipe from the pump letting the bulkhead turn. Another option would be to choke the pump a bit by stepping down to a 1 1/2" union and back up to 2" at the pump; It might cavatate. Last thing i can think of is to use the union, add length to the pipe so that I can slightly tweak it back a wee bit, and hog ~3/8" out of the back of the door so it will clear the back of the pump; this is how it is mocked up right now. When I laid out the hole for the sump I failed to take in account the extra 1/4" thickness the doors have to the faceplate which comes up above the cabnet floor forming a pan.

 

[Steve Canyon]

If I understand correctly... how bout machining off (shortening) each side of the union about 1/8"? I don't think it will weaken it. It will cause slightly less sealing surface area though, so be extra cautious with the glue process.

 

[SkiFletch]

Agreed, if length is the issue and you only need 1/4", shave a little off your fittings. They're over-designed anyways. As long as you make sure your edges are burr-free, use enough glue, and fit well, you should be fine. You really want that true union valve for not if but WHEN you have a pump problem and don't want to have to drain the entire tank.

 

[mr.maroonsalty]

Sorry if Im not clear; with the union on I have 30" to fit a 30 3/16" tank. I can lengthen the distance between the sump and union and get enough room to squeeze the 12 3/4 wide tank in, but I have to take material out of the inside of the door the pump now hits which isn't a huge problem. What I need to do is free up a tank that has the same footprint as the 29 that will be used, so I can see exactly what I can get away with.

 

[Gary Majchrzak]

my suggestions

my suggestions

turn bulkhead so threaded side is inside sump

-OR-

leave out true union and use barb to flex to barb connection instead.
If/when removing pump for servicing plug bulkhead from inside sump with a stopper made of PVC

 

[andrew2010]

They sell these at pool stores . I have used these in lieu of a union and ball valve to accommodate space before. Just pop it in and remove your pump for service.
http://www.americasbestpoolsupply.com/p-5406-tapered-rubber-expansion-plug-1-12-inch.aspx

That's if I am understanding what you want to do.

 

[Vinny Kreyling]

As suggested - shave 1/8" off each piece on each side to reduce the total length.
Just on the union that's only 1/16" away from "just fits".

 

[mr.maroonsalty]

Thanks everyone! I should have just taken a break yesterday. I knew yesterday I didn't want to run without the union; when I did a walk through pump removal without the union I was afraid of potentially blowing out the dollar a gallon glass panel if I needed to apply torque to a well seated threaded joint. I got the breeder in and saw I have just enough room after moving the pump 1" closer to the main sump. I may have to plane my door millwork to a little less than an inch thickness And/or let the tank be the doorstop; all will be good. My original plan was designed around the 40b main sump and DIY custom tank beside it. Keeping cost down I'm instead making due with tanks I already have.

 

[der_wille_zur_macht]

I have to admit I'm a little confused about what doesn't fit where, but the idea of milling out a panel of wood to get the pump to fit has me a little worried. Is the pump literally butted directly against the wood panel? What kind of pump is it? Most external pumps are fan cooled, if the fan has minimal clearance to a flat surface you might start eating motors.

 

[mr.maroonsalty]

Maybe this will help:

My original design had the pump and sump as close they could be with only the union and male fittings in between. I decided not to build another custom sump and use my 29 for a fuge. The footprint of the pump is too big, but by sliding the pump right towards the back side door there was enough room for the fuge tank. When I layed out the bulkhead I failed to add the extra thickness of the door and that's where things got too tight; if I were to keep the true union I needed to move the pump all the way over so the union was to the right of the tank and the pump's end was in the way of the door. Today I emptied a 20b which is very close to the footprint of my 29 and saw things will squeeze in well enough if I turn the 40 out of square, thus pushing the union further back in the cabinet. That made enough room so I could move the pump in away from the side door a heavy inch. Like I said now the worst case is I need to mill my styles and rails a wee bit under an inch to keep the 29 from hitting the union valve; I was uncomfortable leaving it off.