SpudFiles

I just want to know what makes a DWV bushing able to hold less pressure. I am building an over under pneumatic, and the only part need now is a 3" to 2" bushing and im debating wether to buy this part as DWV or is it worth ordering nfs online?

Yep, it is worth ordering nfs-pw online. dwv could explode or pop off.

mcmaster.com Part Number: 4880K612

is this what i want? it says its not pressure rated but it was in the pressure rated catagory. and btw what is "socketweld"x"spiogot" or is that just your standard "glue on both ends" type of bushing.

Look around the edges of the part. If it says 'NSF-pw' or 'D2466' (or something like that...correct me if I am wrong), then you should be OK. Also, If the part is over $4-$5 for that size, it is most likely pressure rated. I get all my parts from ACE and everything up to 4 inches is pressure rated (except for the bell reducers, abs stuff, etc).

Use the dwv it will be fine.

I look at the pipes on mcmaster and it gives the options of
sch 40
sch 80
non rated

I'm assuming that nonrated is dwv and the other two are rated.

Is that correct?

On a brushing i have it needed to be put into a coupling so you may have had the right one but thought it didn't work because it was the same size as your barrel.

DWV is less safe due to the fact that A:it has shallower ..uhh...whatever they are called(blanking) and B: it has less materials used, and therefore it it weaker.

if you want i could explain why it had less materials due to the shape, but its kind long...and it would take a while

well dwv comes in sch-40 but that does not mean it is pressure rated.
DWV has shorter socket depth.
on mcmaster, all of their sch-40 and 80 pipe are usually pressure rated.