Pressure cooker at 1 atmosphere?

Click For Summary

Discussion Overview

The discussion revolves around the operating pressure of a standard pressure cooker and its relationship to boiling points of water at different pressures. Participants explore the concepts of gauge pressure and atmospheric pressure, specifically addressing how a pressure cooker can boil water at 120°C while atmospheric conditions allow boiling at 100°C.

Discussion Character

  • Technical explanation, Conceptual clarification

Main Points Raised

  • One participant notes that a standard pressure cooker operates at 15 psi, which they equate to about 1 bar, and questions how this allows water to boil at 120°C.
  • Another participant suggests searching for "gauge pressure" to clarify the concept.
  • A subsequent reply confirms that the 15 psi measurement refers to pressure above atmospheric pressure.
  • A participant expresses gratitude for the clarification provided.

Areas of Agreement / Disagreement

Participants generally agree on the distinction between gauge pressure and atmospheric pressure, but the initial confusion regarding boiling points at different pressures indicates some unresolved understanding.

Contextual Notes

The discussion does not resolve the underlying assumptions about pressure measurements and their implications for boiling points, leaving some aspects of the topic open for further exploration.

adoion
Messages
55
Reaction score
0
Hi,

I just read that the operating pressure of a standard pressure cooker is 15 psi or about 1 bar and they claim that water boils at 120C or 250F at this pressure.

But atmospheric pressure is 1 bar in Paris and almost 1 bar in most countries in the world, here is a link I found http://www.engineeringtoolbox.com/boiling-point-water-d_926.html.

So please someone explain how a pressure cooker can boil its water at 120C with 1 bar of pressure and the atmosphere boils its at 100C with 1 bar of pressure. ?:) what's going on here guys?
 
Physics news on Phys.org
Google "gauge pressure."
 
  • Like
Likes   Reactions: Doug Huffman
All right so if it says 15 psi its actually 15 psi above atmosphere??
 
Correct.
 
Ok thanks man, very helpful :)
 

Similar threads

High School Problem with understanding deriving Torricelli's law
  • · Replies 14 ·
Replies
14
Views
2K
Undergrad Pressure Cooking: How Does It Get Hotter Than 15 psi?
  • · Replies 3 ·
Replies
3
Views
3K
The Clausius-Clapeyron relation to study pressure cookers
  • · Replies 2 ·
Replies
2
Views
4K
High School What actually is static pressure?
  • · Replies 11 ·
Replies
11
Views
3K
Graduate Speed and pressure relative to a piston (fluids)
  • · Replies 3 ·
Replies
3
Views
4K
Pressure Cooker Internal Energy Problem
  • · Replies 2 ·
Replies
2
Views
2K
Graduate Effect of freefall on hydrostatic/atmospheric pressure
  • · Replies 8 ·
Replies
8
Views
5K
High School Cheapest equipment to boil water at 60℃
  • · Replies 15 ·
Replies
15
Views
4K
Optimizing Pressure Cooker Steam Release: Weight Calculation for Boiling at 120C
  • · Replies 2 ·
Replies
2
Views
7K
How does water vapor in the atmosphere form under normal conditions?
  • · Replies 12 ·
Replies
12
Views
7K