No Stupid Questions @lemmy.world ramble81 @lemm.ee 8mo ago

Does different parts of the world use different standards for water pressure similar to voltages?

In the US for example the standard is 110V for voltage and 80psi for water. In Europe, voltage is 220V, is water pressure different there too?

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Water operates more like DC voltage so there isn’t really a need for a standard. You just need enough to get to your shower head.
- That’s an interesting analogy. But just like too much current can melt a wire, I would assume there’s some upper limits to keep it from bursting pipes and fittings?
  
  I think it’s 80psi/20psi to code.
Afaik water pressure is variable based on each city's design needs.
- Everyone else is focusing on whether the rest of the world uses metric and not that fact that water pressure at a given faucet or shower head will be governed by bernoullis equation which will take 99 things into account such as:
  
  The max height of the water reservoir
  
  The height of your faucet
  
  The design of the pipes leading from the reservoir to your faucet
  
  Air pressure
  
  The pumps in the system
  
  Etc
- And the location of the house/apartment. Houses higher up have lower water pressure and in apartment buildings the upper floors have lower pressure than bottom floors. 1bar of pressure lifts water 10 meters high. When constructing heating lines on a new building we might have the heating on on the first 3 floors despite the ends of the pipes leading to upper floors still being open and half of the building missing. The water wont spray out as long as we keep the pressure low enought that it doesn't rise to where the pipes end.
Noggie here. Code dictates a minimum of 2Bar (~30psi), but it's usually between 3-6 bar.

The pressure at my house was recently measured as I had some plumbing work done, and in my 2nd floor bathroom it clocked in at around 5 bar (75ish psi, I think)
Here in the UK the legal minimum is 1 bar per 10m of elevation. But usually the tap will have between 2 and 4 bars of pressure. Older buildings might only have 1 bar ofc. And by older I mean stuff that was built centuries ago and proper modern water supply is impossible to install.
My house is operating at around 3,5-4 bar after the pressure regulator. Since I have no gauge I can‘t deliver the pressure of the supply. I guess it is around 6 bar. Small town in Germany.

We also have mandatory check valves since a couple of years to prevent water from entering the supply from the buildings in case the pressure drops.
Not European, but I think they might not use PSI since that's Pounds per Square Inch. I believe they use Pascals/ Bar.
- In Germany at least I think th most popular unit is Bar
  
  Portugal is the same.
- Doesn’t really matter the unit of measurement. Kinda like hp/ps or lb-ft/nm, there are equivalents. I’m more interested in the values, but you do have a valid point there.
  
  Well, you're asking about other countries and literally no one knows what PSI is :)
Australia uses kilopascals rather than PSI. Our standard is 500kPa which works out at around 72 PSI.
The most common one is bar. 1 bar is roughly the atmospheric pressure.

An older German unit was atü, 0 atü is atmosperic pressure

Edit: sorry I misunderstood the question
- So, a hole in a bucket? Doesn't sound right.
  
  Gauge pressure not absolute
80psi

different there too?

Of course, because psi exists only inside Usa. The real world does not use body parts for measurement anymore ;-)
- I use Torque per cubic foot.
  
  Stork's foot or crocodile's?
In europe they mostly use Bars as the unit of measurement.

Mostly water pressure is around 1-2 bars as a minimum, but there are still places using different standards, for example the old style gravity-fed UK watersystems with sub 1 bar pressure, but those are not very common anymore.

Most domestic sanitary products in the EU are designed to be used on 1-5 bar pressure.

I read somewhere the domestic water pressure to be between 4-6 bar, however not sure how realistic it is accross the whole EU and also what you got at the mains and what you got when opening the faucet is two different numbers.
- A bar is 100,000 Pa or 100.000 Pa. Why not use KPa? Why set a separate unit to be 1E+05?
  
  Because 1 bar is almost atmospheric pressure. Oddly enough I've never seen anyone use kPa, weather forecasts often use hPa (instead of mbar) to report atmospheric pressure.
  
  No idea what is the story behind it, or if there is a practical reason.
- Will any pressure below 1 bar work at all? Wont it just suck the air in instead?
  
  These pressures are all gauge pressure, not absolute pressure. 1 bar gauge pressure would be about 2 bar absolute.
  
  The gravity systems in this case are not pressurized. They just have a water tank in the loft/airing cupboard and the hight of the tank determines the pressure. 0.1 bar for every 1 meter height. You open the faucet and gravity pushes out the water.
  
  Its a nightmare, I used to live in UK and these systems are barely enough for anything really.
  
  1 bar is enought to lift water 10 meters up. The pressure gauges reads zero at atmospheric pressure.
It's 120V and 240V
- It's 230V in Europe.
  
  What genius decided to denote the difference by using three shades of the exact same colour?
- Is that substantial though or is it like calling 120V something like 110V/115V?
  
  It doesn't matter one bit. The actual voltage from the wall varies, and devices are build to operate under a fairly wide margin.
  
  Hes just being pedantic. Reality is US houses get a +120v and a -120v supply. Combine them is how you get 240v.

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