# Questions tagged [pressure-vessel]

Containers that are designed specifically to retain internal pressure or a vacuum

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### Why do we neglect the radial stress in case of a thin pressure vessel?

A cylindrical or a spherical pressure vessel, having inner diameter $d$ & thickness of wall $t$, is called thin if $\large \frac{t}{d}<\frac{1}{20}$. $\bullet$ Thin cylindrical pressure ...
69 views

### Easily compute a good approximation of heat conductivity of cooled semi-vacuum (water vapor + air)

I am preparing a classroom demonstration about heat, including a demo of how a satellite loses heat only radiatively, since it's flying through a vacuum. I'd like to make the vacuum-production ...
139 views

### How to calculate the pressure loading of a vented silo explosion?

I would like to independently check a vendor's silo design for proper explosion venting. Worst case, it is essentially cylinder filled with a stoichiometric mixture atomized sugar dust and atmospheric ...
176 views

### Making a radial (only) seal inside a small tube

I'm trying to make a adaptor to fit a nozzle about 5mm wide which only applies pressure radially during insertion. Pushing in a standard O Ring would apply some force axially up or down the inlet due ...
3k views

### Calculating maximum internal pressure from maximum rated external pressure?

Is there a calculation / rule of thumb that can determine a containers rough maximum negative pressure (vacuum) from it's rated internal pressure (assuming a single layer construction so there is no ...
2k views

### Minimum thicknesses of an elliptical cylinder pressure vessel

For pressure vessels in the shape of circular cylinders, we can use $\sigma_{hoop}=\frac{pr}{t}$ to find the minimum skin thickness by setting the hoop stress the maximum allowed value, and then ...
623 views

### How to remove protective valve cap from CO2 cylinder?

I have received a CO2 cylinder from an online seller fitted with a protective cap over the valve: I understand these should unscrew, but this one appears to be stuck very firmly. Is there a standard ...
2k views

### Determine force distribution from a bolt pattern

Need some help designing a bolt pattern for a pressure tight enclosure. How do i determine the force applied at a distance from a bolt location so that I meet the minimum force to compress the ...
83 views

### Why is the thin-walled cylinder more likely to experience failure along its axis than along its hoop/circumference?

I was watching a YouTube video to understand the concepts of hoop/circumferential stress and axial/longitudinal stress in thin-walled cylinders and their formula derivation. So the formula of the ...
145 views

### How does a pressure vessel fail when the interal pressure exceeds the yield stress of the material?

When we design a pipe or pressure vessel, we look at hoop stress and longitudinal stress and then look at the material properties. We assume that the material reacts to the load as a solid. However ...
91 views

### A question on mechanical failure

Suppose there is a rod, on the wall or at the centre, in a pressurized vessel, the pressure inside the vessel being P. The rod has a shear strength of S. Is it true that the rod will break, in shear, ...
295 views

### Is this pressure vessel feasible?

I am intending to construct a small pressure vessel. It needs to be around 7 centimeters in length and width and around 1-2 centimeters in depth. It must be capable of being pressurised to 300 psi ...
14 views

### What's the best type of steam Trap for Superheated Steam?

Process Engineering Newbie here. What kind of Steam Traps are best suited for condensate removal in super-heated steam line or manifold? The super-heated steam is to be supplied to a process reactor ...
31 views

### How to apply the permeability value found from an experiment?

I have done a permeability experiment on LDPE in the presence of air using a 25mm circular specimen. At 30'C, the permeability was found to be 1.846 barrer. Now I am trying to apply this permeability ...
827 views

### How much pressure would I need to push water out of tank?

How much pressure would I need or, better yet, how do I compute for the pressure required to push water out of a submerged tank? Do I use 1 meter as head or 7 meters? (Please just bear with the ...
219 views

### Thin walled pressure vessel

What is the NORMAL STRESS in a thin walled pressure vessel? I am aware of only 2 types of stresses in thin walled pressure vessels: Longitudinal & Tangential. Is any one of these 2 is ...
228 views

### Why divide the dimensions of a pressure vessel by 39.37 when calculating discharge capacity?

For a National Board Exam Review: A 29.53" * 39.37" pressure vessel contains ammonia with f = 0.041. Compute the minimum required discharge capacity of the relief device in $\mathrm{\frac{kg}{hr}}$...
17 views

### Regulating pressure down inside vessel as it increases

I want to keep the pressure inside a balloon (effectively - a rubber vessel) constant, as the balloon is compressed. I'm wondering if a regulator like this (wiki page here showing mechanism - I ...
463 views

### Tubing for explosive gas or hydrogen transfer

Recently, I heard that there is a law/ OSHA/ ASME piece of regulation dictating that hydrogen should be transferred (suppose from a tank of hydrogen to another location) by using specially approved ...
31 views

### Can I increase the range of a howitzer by using more propellant?

The muzzle velocity of a firearm can, all else equal, be increased by lengthening the barrel of the weapon which can theoretically be extended up to the point that friction and air resistance would ...
157 views

### Check valve with precise cracking pressure

I have two containers of air, one at 100 kPa and rising, the other at 30 kPa and decreasing. I need a valve that lets air through when the pressure difference is >70 kPa. Where would I find a valve ...
43 views

Can I use a conical head at the bottom for a small diameter steam manifold ( Schedule 40- 3 inch dia. and 2 inch dia. ) that needs to operate at high temperature (~450 deg Celcius) and High design ...
81 views

### What is this part called, and where could I get one?

I'm fairly illiterate when it comes to Engineering, so please understand I have pretty much 0 idea what I'm talking about. I'm having to build a seawater distillation device for school, and we ...
89 views

### Designing a horizontal pressure vessel

The question reads Design a horizontal pressure vessel with hemispherical head supported by saddle support and fitted with 2 nozzles welded to the head. It's used for storing and delivering fuel ...
36 views

### What is the criteria for bubble entrapment in a closed headspace tank set to drain?

Suppose a closed tank does not have any pressure relief system and is set to drain from the bottom. It is said that because the headspace pressure drops as the liquid level goes down, the tank will ...
83 views

### Why is gas pressure specified instead of mass flow?

Clarification: This question is all about the gas supply to the water heater. It has nothing to do with the water supply. My hot water heater specifies 5.5-10.5 W.C. (water column inches) of pressure....
27 views

### Collapsable Water Tank

I have been wondering, would it be possible to make an 8’x4’x’5 tank that can be put up and taken down as needed, where you would have a base, four removable corner posts, more removable posts as ...
28 views

### Why can't I find a small vacuum fryer?

I'm looking for a vacuum fryer and so far the only ones available to buy are large, industrial machines. Is there some technical consideration that makes small scale machines economically unfeasible? ...
39 views

### Are tube fittings a feasible way to create tight seal?

I'm doing an experiment where 2 electrodes are inserted into 2 openings in a cylinder holding electrolytes to measure its impedance. We want the openings to be tightly sealed because the cylinder ...
1k views

### When calculating the deformed radius of a pressurized thick-walled cylinder, why is the hoop strain used rather than the radial strain?

The context I’ve taken an interest in the design of pressure vessels for use in submarine applications. From a cursory survey of what is used in industry, it seems the de facto standard housing is a ...
110 views

### Equations for stress in a hollow prolate spheroid under external pressure

Are there analytical expressions (functions of geometry and applied pressure) for the stress in a hollow prolate spheroid, like there are expressions for the stress in a hollow sphere/cylinder?
33 views

### Pressure-volume relation of thin-walled shell [closed]

Attempt to edit into a more specific question as suggested by moderator: I would like define the shape and material properties of a 3D thin-walled shell/membrane-like structure (for instance a baloon)...
1k views

### Plane Strain examples

Trying to find examples of structures, components etc. in plane strain (under normal loading conditions). Is a thin-walled-pressure-vessel in plane strain? (I thought it was plane stress but could ...
766 views

### How to calculate external pressure resistance in spheres and cylinders?

Although I have seen a lot of literature online about how internal pressure resistance is calculated (i.e the pressure in a gas tank) I haven't found anything about the opposite scenario (i.e the ...
91 views

### How do you get a closed vessel to >90,000 psi internal pressure

Im trying to build a cold isostatic press with a internal vessel area of 300mm3. A cold isostatic press forms green metal components using pressures greater than 90,000 psi. Using an oil or water/...
1k views

### How to determine minimal wall thickness for a rectangular pressure vessel?

I know this is a basic question but google only gives formulas for more "rounded" shapes. How to calculate the minimal thickness for a flat wall knowing tensile strength of the material and the ...
41 views

### Wall temperature of pressure cylinder - Boundary condition

I have a thick-walled pressure cylinder, that transports fluid and experiences only internal pressure. During the process, the outer wall temperature is measured. And I have no clue about the inner ...
62 views

### Can a water pressure switch be used as a low-water cutoff means for a steam boiler?

Steam boilers obviously need to be protected from the catastrophe of running out of water -- you then either get a meltdown if the boiler is fired unwatered for an extended period of time or a boiler ...
2k views

### Liquid vs. gas check valves

Suppose that I want to transport gases in a tube in only one direction. Can a liquid check valve be used in place of a gas check valve or is there a specific reason to use only a gas check valve?
257 views

### Burst pressure of a sphere

Is there a formula for the burst working pressure of a spherical pressure vessel that takes into account its material peoperties? It should be noted that this is not a concentric sphere design (it has ...
616 views

### Will helium gas lift more weight in air when it is spread over large volume compared to equal weight heavily compressed small volume?

Is it possible for a weather balloons filled with helium gas to lift the weight of itself and a helium tank(highest psi possible) which can fit the volume of the lifting gas in it? Assuming a typical ...
71 views

### Ideal gas law, theory vs reality

I am trying to get an idea of the amount of hydrogen that I can store in some pressurized steel tanks underground. Based on the ideal gas law PV=nRT I did a simple calculation pressure = 200bar ...
353 views

### Measure stress of gas acting on a spherical container

How can I measure stress in a thin- walled sphere containing a gas? Is there a way to predict what the stress will be without actually needing to fill a sphere with gas? I am talking about hoop stress/...
20 views

### Angled Nozzle on Pressure Vessel - Weld Preperation

I wonder if anyone can help! I'm trying to model 3D geometry of nozzle to shell weld. I am having issues ascertaining correct bevel angle at a given point. Surely the bevel angle would change due to ...
36 views

### How could you produce large quantities of metallic hydrogen?

Could you somehow crush hydrogen atoms with magnetic fields in order to produce it? Or maybe someday someone will invent a material capable of withstanding 500GPa and we'll have giant machines that ...
54 views

### Analytical solution of thermal stress in a bi-metallic cylinder

As a side project I have looked to solve using Python an analytical solution for one-dimensional transient heat transfer in a thick cylinder with cladding on the inside surface, wherein the fluid in ...
105 views

### Kinetic energy of a balloon

How do I quantify how much kinetic energy would be released from popping a balloon? I believe that any additional kinetic energy that results from the balloon will come from it being pressurized, but ...
28 views

### hydrostatic storage of gasses

This question is a bit general but hopefully someone can point me in the right direction. If you have a metal container, welded shut that's fitted into a hole that is say 10 meters wide and 30 meters ...