Weld on bung or tap? not automotive related

For one of my very large sand blast pots I am adapting it to a new metering valve on the bottom of the pot. On the bottom of the pot there is a removable plate that has a 1" hole that I want to bore and tap to a 1 1/4" hole. What I am wondering is would it be better to weld on a 1 1/4’ bung or bore out the hole and tap it to 1 1/4" The pressure in the pot would not exceed 180 psi.

what’s it made from?

How thick is the material?

Also, about your screening question, i might be able to help you out… MAYBE. How much will you be screening at one time?

The material is steel and it is 1/2"

as far as the screening there is not a specific amount that has to be done it is more to see if the remaining media can fall under the category of our fine size. Probably anywhere from 300lbs-500lbs a day.

Well 1/2" steel is plenty to tap. I think it would come down to cost and what you currently have. I am sure 1.250" taps are not cheap and I am sure they are a pain to do by hand. Plus what are you going to use to cut the whole nicely to tap it? With cost and time involved you might be better off buying a bung already threaded and weld it on

My uncle owns a machine shop so I was going to ask him to do it. I just wasn’t sure if I would be better to weld on a bung or to tap it.

is it NPT?

1 1/4 NPT has a pitch of 11.5 TPI, so you will only have 5.75 Threads less the chamfer… For pressure rated applications it’s usually a good idea to have 6 threads of engagement, and about 9 total threads.

However, if you’re planning getting it welded, don’t let some hack do it. Pressure vessels are fairly important to have welded properly.

[quote=“newman,post:6,topic:39841"”]

don’t let some hack do it.

[/quote]

:biglaugh: ain’t that the truth

yes it is npt

[quote=“newman,post:6,topic:39841"”]

is it NPT?

1 1/4 NPT has a pitch of 11.5 TPI, so you will only have 5.75 Threads less the chamfer… For pressure rated applications it’s usually a good idea to have 6 threads of engagement, and about 9 total threads.

However, if you’re planning getting it welded, don’t let some hack do it. Pressure vessels are fairly important to have welded properly.

[/quote]

1/2" is on the low side too. The hole is beveled a bit on the inside.