What is this union?

[MSB123]

Measure the ID of short piece of pvc pipe going into the union with a pair of calipers.(pic 2 looks like a slip union and slip bulkhead connected with a short piece of pipe).

Now you have 2 options.
Take 1/2 the union to a plumbing supply house you can find out what will match it.
Order 1 on amazon or some other internet site. See if it fits. If not order form another site and see if it fits......... repeat until .....

That might be what I need to do.
I have tried the store, no luck.

 

[redfishbluefish]

Well then your best bet, if you could take one of the old union ends, would be to go to your local plumbing supply house. If they are anything like my supply house, they look at homeowners like we have the plague, and really don't want you there. Hopefully you'll have a good one that will work with you. See if they could match what you have or maybe tell you who the manufacturer might be.

And I wouldn't buy Hayward parts...only if that union was actually Hayward. They are a pool manufacturer, and you put the word "pool" on an otherwise common part, and they charge you five times the cost. Believe me, I know....I have a pool.

 

[MSB123]

Makes sense. I have looked at 2” unions, and they are all about $25. Not too much more expensive. I will go to the store tomorrow.

Well then your best bet, if you could take one of the old union ends, would be to go to your local plumbing supply house. If they are anything like my supply house, they look at homeowners like we have the plague, and really don't want you there. Hopefully you'll have a good one that will work with you. See if they could match what you have or maybe tell you who the manufacturer might be.

And I wouldn't buy Hayward parts...only if that union was actually Hayward. They are a pool manufacturer, and you put the word "pool" on an otherwise common part, and they charge you five times the cost. Believe me, I know....I have a pool.

 

[redfishbluefish]

Where are you looking....HD, $11.31.

 

[Gobi-Wan]

So are you trying to connect the sumps by 2 connection points? Because it looks like you have both halves of that union... If so, the other union just needs to be the same overall length or shorter. I'd just look at a home improvement store, they all carry PVC unions. If you're looking for something to fit a new half on an old half, I'd wager most unions use the same thread. The gasket just has to have pressure for a seal. And can you remove the bulkheads? I would just start over with new bulkheads and new identical unions.
Edit: looks like some people here have tried mix and match without success. I'd just go with the new bulkheads and unions.