PVC Pipe Pressure Weight 2

[Mandrill22]

I'm trying to put lead shot into a 6" PVC pipe and cap it. If I put 300 lbs worth in, would the cap below hold it? It's ASTM D1784, which says that it's 280 psi rated. I would use the PVC cement. The items I'm looking at are from McMaster below.

PVC Pipe
Pipe Cap
Pipe Cement

 

[alchemon]

If you were to fill a 6” sch. 40 PVC pipe with 300 lbs of material, yeah the pipe should be fine...

If you try to use to shoot whatever inside out, yeah you’ll have a problem.

 

[Mandrill22]

I didn't understand the second sentence

 

[LittleInch]

Why are you doing this?

How long is the pipe and is it vertical?

Is the pipe suspended so the cap at the bottom isn't on the ground?

Remember - More details = better answers
Also: If you get a response it's polite to respond to it.

 

[alchemon]

I guess I biasedly read your usage of "lead shot" in a pipe to indicate that you were trying to make some kind of homemade cannon - or other quarantine "bored at the house" project (i.e. to shoot the lead shot out of the pipe) .

The pipe fusion by the cement, if done properly, will be as strong as the pipe. This is really a fairly simple fluids problem - we can determine the pressure at the bottom using the density of lead, with the height of the column and orientation.

For purely vertical:

A quick search of google says that the density of #8 lead shot is ~ 435 lbs/ft3. 300 lbs of the shot is then something around 0.69 ft3. The cross sectional area of your pipe is 0.2 ft2. Therefore, the pipe is something like 3.5 ft long.

Pressure at the bottom is going to be: P = density * height = (435 lbs/ft3)*(4 ft) = 1740 lbs/ft2 = 12 psi or so. If you believe that the finished weld is good up to that, i don't think you will have a problem. Check my math though, it is still pretty early here.

 

[cvg]

assuming the inside diameter is exactly 6 inches
area of the cap is 28.26 sq inches
mass of lead is 300 lbs
pressure is mass / area = 10.6 psi
not counting the silo effect, the pressure might actually be less

 

[Mandrill22]

Does anyone know enough about PVC to know if it would be crazy to try to NOT cement the threads?

 

[alchemon]

The pipe in your original post has a threaded end. The cap is a socket end. You will have to pick one or the other. You don’t cement threaded joints, you use thread tape. If it were a true pressure joint, do you have a pipe wrench big enough to turn a 6” fitting on tightly? Either should work.