Question about unions

[andrsn]

I am in the plumbing stage of setting up my new tank and was wondering if someone could help me out. I am using both overflow holes as the drain and emergency drain with the return coming up the back using an oceans motions 2way. The main drain will be with pvc and the emergency will be using flexible pvc or spaflex. My question is after the bulkhead i want to have unions and I don't know exactly what type I need for the flex pvc. Also do I need any type of fitting after the bulkhead or should I glue the pvc right to it then the union. Thanks. Bill

 

[alpha0r]

You can glue Spaflex just like regular PVC. I don't like to glue hard pipe directly into bulkheads without some way of removing it (union, threaded fitting, ect.) because you might need to change the pluming or fix something and hard gluing can cause headache.

 

[andrsn]

AlphaOr thanks for the help. Are you saying though to have a threaded fitting in the bulkhead? Or have a piece glued then the union to that. I have a barbed bulkhead from the AGA megaflow kit and was planning on buying another for the pvc but slip.

 

[JohnK]

I would either use a threaded unuion, or if you do use slip then leave a few inches of pipe between the unuion and the bulkhead. That way, If you have to you, can cut the pipe but still be able to reassemble it using a coupler.

 

[Ray]

Just wondering why you want to put a union on a drain after the bulkhead? Do you plan on changing your drain configuration often? If you ever need to change the bulkhead you are going to have to cut the union off to get the bulkhead out.
I would glue directly to the unions, if you ever need to redo your plumbing then bulkheads are cheap enough to replace or you can use a coupling on it and re use it.

 

[MikeG]

Flex pvc or spaflex uses regular pvc fittings. sounds like you are talking about vinyl hose on the drain though when you mention a barbed fitting. These are two different things and use different fittings. Vinyl or flexable hose uses barbed fittings not pvc fittings.

I always use threaded bulkheads and screw a male adaptor with a union connected to it into the bulkhead. This way I can change plumbing at any time without removing the bulkhead or cutting anything, and I can also remove the bulkhead and reuse if I ever need. Has worked quite well.

You can see how I normally have my drains done here

 

[alpha0r]

I would either use a threaded unuion, or if you do use slip then leave a few inches of pipe between the unuion and the bulkhead. That way, If you have to you, can cut the pipe but still be able to reassemble it using a coupler.

^^^ This is what I am saying.

 

[andrsn]

Thanks everyone for your help and suggestions. I dont plan on changing the drain setup anytime soon, but when I do have to remove it eventually I dont really want to have to cut anything so that was the reasoning behind using a union after the bulkhead. And to mike G your idea sounds like something that may work for me for what I was trying to do

 

[Ray]

so Mike, the union will fit up through the hole the bulkhead is in? I didnt think it would fit but I have never checked.

 

[JohnK]

so Mike, the union will fit up through the hole the bulkhead is in? I didnt think it would fit but I have never checked.

No it probably won't, but by using the threaded bulkheads (and unuions nearby) you can unscrew the fitting from the bulkhead. (look close in the pic Mike posted, you can see the male thrd adaptors)

 

[andrsn]

I guess I will ask another question I am not sure of then. On my tank in the eurobracing there are two holes which i plan on using for the return. I am going to have a 3/4 bulkhead and an elbow so the flexible pvc can be clamped to. What I am unsure about is what can I use in the tak connected to the bulkhead. Something like locline was what i was thinking but I dont know how it would attach to the bulkhead. I have a picture so give me a minute and I will try to post it

 

[reefsmurf]

I keep seeing "true union" pvc pieces.. is there such a thing as a union that is not true?

 

[andrsn]

This is the same tank and what I was talking about

 

[JohnK]

Yes, locline will work fine, you might just have to replace those bulkheads with threaded ones so you don't have an extra adaptor visable in the tank. Be sure to include a siphion break of some sort though.




True unuions are double unuions with a ball valve in the middle. Unuions are just unuions. Why they are named like that? I have no idea??

 

[andrsn]

Yes, locline will work fine, you might just have to replace those bulkheads with threaded ones so you don't have an extra adaptor visable in the tank. Be sure to include a siphion break of some sort though.




True unuions are double unuions with a ball valve in the middle. Unuions are just unuions. Why they are named like that? I have no idea??

Thanks I think I am going to try and order some stuff tonight as well as go to home depot.

 

[MikeG]

Thanks I think I am going to try and order some stuff tonight as well as go to home depot.

I would try lowes if you can. HD usually has a really poor PVC fitting selection, pretty much just your standard fitting. Lowes has many more options.

 

[Ray]

No it probably won't, but by using the threaded bulkheads (and unuions nearby) you can unscrew the fitting from the bulkhead. (look close in the pic Mike posted, you can see the male thrd adaptors)

AHHHH ok I get it now! Thanks for clearing that up, that is a great idea!

 

[JohnK]

I would try lowes if you can. HD usually has a really poor PVC fitting selection, pretty much just your standard fitting. Lowes has many more options.

Mike, that's because I've thouroghly pilliaged YOUR local HD incessently since they opened, they can't keep up with me


Also, you'll never find true unuions at HD, but Lowes usually stocks them but in slip only IME.

IME marine depot is good for ordering the plumbing parts you can't get locally. Usplastics.com is IME, great for getting hard to find schedule 40 parts and pipe in grey, and anything schedule 80 (which there is no reason to use, but it's still cool to know if someone wants to try building a "high pressure Ca reactor") They also have much better quality valves and true unuions than you can find locally.

 

[MikeG]

Mike, that's because I've thouroghly pilliaged YOUR local HD incessently since they opened, they can't keep up with me
QUOTE]

The main reason I prefer Lowes is they carry all the oddball street elbows and reducer bushings and such to go from crazy things like 2" to 1/2" with one fitting where if you try to do that with what you find at HD, you end up needing like 5 fittings to get to the same place.

 

[alpha0r]

The main reason I prefer Lowes is they carry all the oddball street elbows and reducer bushings and such to go from crazy things like 2" to 1/2" with one fitting where if you try to do that with what you find at HD, you end up needing like 5 fittings to get to the same place.

I agree. HD never has the parts I'm looking for. The one in salem doesn't even have 1/2" to 3/4" bushings. This is really not an oddball part.