Air pressurized water Puns

I am swapping sinks, so I turned off the water lines under the sink, then popped off the flexible tubing. Well, unbeknownst to me, the valve for the hot water line was so rusted that it no longer closed. Cue spurting water and panic as soon as I started unthreading the coupler.

I go downstairs to my hot water tank, shut off the breaker, and close the outlet valve. I go back upstairs to remove the tubing from the valve, and whaddya know, that fucker is still leaking. I thought it might have been residual pressure in the line but it has been going for hours. Also it is ice cold water.

Neither the upstairs sink or the shower have any water coming from them on full hot, but basement shower and sink both spit out cold water on full hot (even with the cold valve shut off, so I know its from the "hot" line).

Am I a dummy? Why is there cold water in my hot water line?

Any insight would be much appreciated, thanks.

I've been mulling on that classic line from Pirates of the Carribbean, where they tied a heavy objects to Bootstrap Bill's bootstrap, and threw him overboard. What got Bootstrap?

I've often wondered it when I've been on a boat myself. If stuck to a heavy object, what would kill a person first? The intense ocean pressure or the lack of air/drowning?

(Just out of morbid curiosity - no risk of self-harm)

Would the system curve from suction to delivery just start at negative head for 0 flow, where the value is the pressure in the pipeline?

For example a small pump pumping from a main with 30m head into a tank.

ECM Synchronika plumbed in - ok for machine power to be OFF while braided hose still connected to machine with water pressure?

Manual said something about shutting off the water supply like when off, got confused cause I hadn’t heard of people doing this?

Howdy folks! Question for y'all, what ideas are there for pressurized water? I can think of gravity and a portable gas pump. This would be used for gardening from a hose. I currently carry my water where I need it, and it's a bit of a pain at times. Gravity isn't an option outside of my cabin, however, as there's nowhere elevated enough to be of benefit. I'm leaning to the pump idea, as that just seems like a good thing to have, but thought I'd see what other ideas exist. Thanks!

Edited to add: thanks for the responses folks! I should be able to sort something out. I'm trying to figure out how to nurse some grass seeds I just sowed while we endure a drought. Eventually I'll get a deck built on the cabin and can have an elevated water supply as a result, but until then... it's haul the water everywhere or pressurize a pump/the tank. Thanks again!

I randomly thought about this a couple days ago then forgot it, but today it came back to me so I decided to ask...

I remember seeing a fire piston on YouTube that works by compressing air until it gets hot enough to ignite a piece of tinder. Then on the weather forecast I heard that a high pressure air system is coming in and it’ll lead to a cool front.

TLDR: The title

I'll give some quick background, that you can skip, to explain my situation. My friends and I started a D&d campaign in a Victorian, Bloodborne setting that doesn't have any magic but encourages things such as trick weapons and gadgets that require some logical basis. I remembered this old anime recently that I watched years ago where a lot of the characters used interesting weapons but the one that stood out to me was a sword that used either pressurized air or blank shotgun rounds to accelerate the blade. However, I'm not sure if that has any real-world logic.

Anyways, I'm not an engineering major but I was wondering if this concept or something similar could actually be viable in the real world/melee combat. To describe how it looks like it worked in the show, the blade used shotgun blanks that were stored inside the hilt. This would cause some sort of reaction that would travel up the blade and release some sort of small explosive charge out of holes near the top of the blade to help propel/accelerate the blade during a swing. I couldn't find anything similar searching online. The closest thing with a similar concept I could find online was the ballistic knife.

I figured you guys would be the most knowledgable on something like this. Any input is appreciated. Thank you.

It's not too difficult to adapt to small changes in atmospheric pressure, as shown by the various altitudes that people live in. So I figured why not increase the pressure inside your home slightly, so flies can't get in (and the ones already inside will get pushed out)? All you need is a compressor to maintain the elevated air pressure.

I've got a space station with a detachable transport ship on its "belly." They are connected using a 5x5 square of merge blocks on either ship to allow pressurized passage between them. Along with the merge blocks, both ships have an airtight hangar door that close before separating so that each ship will remain pressurized. However, when I disconnect the merge blocks, the transport ship immediately loses its pressurization and starts to re-pressurize without any of my input. I've resorted to depressurizing the transport ship before disconnecting the merge blocks and then repressurizing. Nothing that I do will fix this! Please help!

I know, a very odd and specific question. I'm not expecting anyone to actually put the time into answering this but if you want to, knock yourself out.

If neither of these are correct, how does it work in that context? This is for a fun little science project

More about the incident here - https://en.wikipedia.org/wiki/Lauda_Air_Flight_004#Lauda's_visit_with_Boeing

Also covered in Season 14 Episode 2 titled 'Testing the Limits'