Metal drinking cup is stuck inside a pressure cooker

[bluebird]

TL;DR Summary

how to get the glass put of the pressure cooker

the steel glass is stuck diagonally inside the press cooker, getting it out by brute foce didn't work and neither are we able to rotate it. Washing it with soapy liquid didn't work either. Any ideas on how I can get the glass out?

 

[Dale]

How did it get in?

 

[berkeman]

Welcome to PF.

Tilt it until the cup is vertical, and then fill the cup with ice water.

 

[jack action]

Heat up the pressure cooker. Ideally combined with @berkeman 's solution.

 

[hutchphd]

Is the pressure cooker still good? Can you still maneuver the lid in?
If so then bring it to pressure with a very little water (<1 oz) and carefully turn it upside down in the sink to cool while holding the pressure balancer on (wear oven mitts or welding gloves live steam will burn you badly!) Maybe whack it a couple of times while upside down . Again avoid the live steam!
A safer way to pressurize would be to use compressed air. Most pressure cookers run at ~15 psi gauge pressure.
Wear gloves and goggles

 

[Nugatory]

I would start with the @berkeman/@jack action solution - heat the cooker, chill the steel cup. That's the goto for just about anything involving interference fits and metal, and I'd be surprised if it didn't work.

But if it doesn't.... Are you willing to sacrifice the cup? If so, use a cutoff wheel to slit it starting at the rim and going a few inches towards the base, then repeat your previous applications of brute force.

 

[dlgoff]

... fill the cup with ice water

Yep. That was my thought.

 

[berkeman]

Yep. That was my thought.

Or LN2, if that is available...

 

[dlgoff]

Or LN2, if that is available...

LOL. If I were still in college working with the particle accelerator, I'd have plenty of that.

 

[hutchphd]

LOL. If I were still in college working with the particle accelerator, I'd have plenty of that.

It was nice having LN₂ in the basement......I remember several successful wart removals as well as a few less prosaic applications!

 

[Baluncore]

1. The aluminium pressure cooker has a higher thermal expansion coefficient, so when heated, it will expand more than a steel cup. Remove the handles from the pressure cooker, so they are not damaged by heat. Place the pressure cooker without its lid, upside-down in an oven. Turn on the oven and listen for when the cup falls.

2. Alternatively, place a loop of wire around the base of the cup, also rotate a hook into its opening. When you pull equally on those two, the opening of the cup will become more elliptical, so the cup will become narrower, and release. Without the base loop, the cup might rotate and jam in tighter.

3. Combine the two, heat and tension.

 

[hutchphd]

@berkeman Small warts on my own fingers! All you need is q-tip and a styrofoam cup. Painless and easy. The warts are very thermally conductive These were not huge lesions!

 

[berkeman]

@berkeman Small warts on my own fingers! All you need is q-tip and a styrofoam cup. Painless and easy. The warts are very thermally conductive These were not huge lesions!

Those are not in my medical scope of practice, so you're on your own. If you want to sneak into my EE lab and "borrow" some LN2, I probably won't notice the small change in the 500 pound Dewar weight...

 

[hutchphd]

I have had no warts since! But I will call if necessary Who says I had a fool for a patient........
I did love freezing stuff for lecture demos.......

 

[hutchphd]

A safer way to pressurize would be to use compressed air. Most pressure cookers run at ~15 psi gauge pressure.

Actually the safe way to do this is to fill the pressure cooker entirely with water and then apply the compressed air with it submerged upside down in a basin full of water.
This is of course how they periodicly hydro-test scuba tanks because there is almost no energy stored in the system should there be a problem.
I think heating the aluminum pressure cooker very hot may not be a good idea for metallurgical tensile strength reasons.

 

[Baluncore]

Actually the safe way to do this is to fill the pressure cooker entirely with water and then apply the compressed air with it submerged upside down in a basin full of water.

Nearly.
Apply water, NOT compressed air, under pressure, from a test pump, through the safety valve hole.

 

[hutchphd]

Air is easier. It won't be enough air to matter if the pressure cooker is full of water at STP to start.
Revision: Duh! you can get 20 psi water out of your spigot Yeah use water Duh

 

[Baluncore]

As used for testing pipes, by filling them with water under pressure, borrow one of these.
https://www.ebay.com.au/itm/112273413496

 

[hutchphd]

That should get the damned thing loose one way or other. I was hoping to maybe allow the pressure cooker to survive the ordeal in usable condition!

 

[256bits]

this is for the guy who wants to do things right.....for a you tube video.

Place the pressure cooker on its side out on the pavement.
Put a 2 x 6 over the pressure cooker to act as a ramp.
Align the cup with the pavement / 2 x 6
Drive one wheel up the 2 x 6 .. slowly ... in slow increments <-- very important.
This acts as a vice, squeezing the pressure cooker from a circular to elliptical.
After each increment of driving up the wooden ramp, try to pull the cup out.
At some point it should...
Post your video to the internet for a million views.

 

[hutchphd]

Better yet one could use explosives strategically placed and ultra slow motion video. Suspend the inverted cooker over a concrete slab. Red button pushed.....BOOM.......clink. Now there's your million views.