That was actually a great idea, but @JamesW is right. Not only did the check valve body explode, it took not one but both of the attached elbows with it. It's all gotta go.Got it. Seems like there’s a chance I could cut on the left side of the broken valve flush and keep the elbow. Straight piece next then 2nd elbow then check valve vertical. seems like having the check valve vertical is a good idea...agree?
The new check valve can go in any position or orientation. Personally, if I could get it to fit, I might leave it horizontal, as it's easier to view that way. But if you put it in the middle of the vertical pipe, it'd be easier to replace next time if this happens again. With both the inside and the outside of the three-way's port now glued up, you won't be able to use that option again. So yah, vertical is probably best. Leave enough straight pipe on both sides of the new check so that you can cut it out next time and put in a new one with couplers.