Why does hot water pressure drop after turning the tap on as the water becomes hot?
608912
It shouldn't. You must have a problem with your plumbing.
49104
Water is too hot, or you may have bad circulation.
654154
1) the water in the tap is stored under pressure.\n\n2) there are gases dissolved in the water (at high pressure)\n\n3) when the water comes out of the tap, the pressure is reduced and the gases can now come out of solution, much like opening a carbonated soda.\n\nIf you wanted to avoid this, boil the water, then let it sit for a few hours. No bubbles will form because boiling removes all dissolved gases. Using this trick also allows you to make crystal-clear ice cubes - why? When all the air is removed by boiling and then the water is frozen, no dissolved air comes out in the freezing cube to make those 'whitish' bubbles. This is how commercial ice cubes are made.
979481
In science you must have studied that the boiling point of water drops with a reduction of atmospheric pressure.\nAt  a pressure of zero atm(atmosphere), which is vaccum, water will boil at room temperature.\nThis boiling is actually the release of the air mixed in the water.\nWhen a pump has a suction  more than 1 atm. which is roughly 27.7 feet, the vaccum created by the pump causes the air in the water to be released as mentioned above.\nThis release of air is known as cavitation.\nCavitation also occurs when the propellor of a boat or ship moves too fast though the water creating a vaccum on the blade surfaces.\nThat is why you see a 'wake' behind a boat or ship
892823
Yes, the water will freeze if no heat is added as the pressure is lowered. I have seen this done in a physics class. A dish of water is placed in a vacuum chamber and the pump is started. As the pressure gets lower, the water boils, but it is boiling at low temperature, it isn't getting hot. After a while, the boiling water freezes solid.
276889
Did you happen to forget the "in" between burn and the? If thats the case, its because the oil at that time is alot hotter then the water's boiling point, so when water is introduced, it rapidly boils and boils away.
1034461
The advantages that you need not fill the water as and when you want to heat the water.\nthe heater is always full of water with the indication of green bulb and red.\nWhen the heater is working the green bulb glows.\nand the heater stops with the indication of red when the water is really heated to the set level\nDis advantages.\nIrrespective of the small quantity you want it makes the entire water load to get heated up.\nHeavy current consumption.\nMeans the increase in cost of electricity bill.\nIf at all you keep the water heater on for 24 hrs then the steam formation takes place on the top and when you open the tap you get steam for sometimes surging out of the out let pipe.
494092
As any sane and decent person would expect, hot water out of the tap will boil faster than cold water out of the tap. However, water that has been boiled once and allowed to cool will boil faster than hot water out of the tap. That's because boiling gets rid of the dissolved oxygen usually found in water, making it easier for the water to boil the second time around.
777054
The product of flow and pressure put out by the power pack is approximately the power available to do work at the remote actuators.\n\nIn a real system, piping, fittings, filters, etc. cause some pressure drop, so the actual power available is somewhat less.
1017824
Hot water will drop in temperature at a faster rate, but the cold water will freeze first except under certain circumstances in a phenomenon known as the Mpemba Effect\n\nhttp://math.ucr.edu/home/baez/physics/General/hot_water.html\nfor more details on the phenomenon
1070639
Something is wrong with this picture... You are getting 0 psi out while putting 30 psi in?  There has to be some pressure coming out.... otherwise the CFM is going to be zero too.  I realize there is going to be some line loss - but your scenario does not account for a loss of that magnitude.  \n\nI'd check that gauge on the output side... maybe switch the in and out and see if the readings change. \n\nCheers!
233219
i think you have a leak pumping waste into your main watter line. turn all water off and call a plumber immediately!
431321
"...it's caused by cavitation, which is a high-tech way of saying bubbles form and then they pop. When you heat water on the stove, the layer at the bottom is the first to boil, meaning it turns into a gas. The water vapor collects into bubbles, which rise toward the surface, passing through cooler water en route. The lower temperature causes the vapor to recondense into liquid and the bubbles collapse, making a noise. This gets gradually louder, as bubble production increases, until the water is so uniformly hot that the bubbles make it to the top without popping. At this point the noise diminishes. But it takes a moment before the vapor pressure builds up sufficiently in the top of the kettle to make it start whistling. That's why you get a brief period of calm before the steam--an incredibly feeble play on words, but a perfectly adequate description of the event."
100913
with out checking it possible that the temperature control might be bad /loose connection some where/ safety switch keeping it off /maybe a bad gas soleniod
239290
This depends on what you wanted in the colorimeter in the first place, are you looking at temperature change rates going up, or down?  Either way, if you mix the two, it will skew the results of your experiment.  Hot water, even at 100 C still may have a lot of ability to absorb latent heat of vaporization before it becomes steam.  Your temperature curve will slow significantly or even flatline for a while if you are increasing temperature.  If you are decreasing temperature, hot water has already lost most of the latent heat of vaporization, it has already become liquid, this will impact your results.
412700
If you put hot water in the freezer it turns to ice faster.\n\nA famous scientist named Kelvin figured that out because hot water molecules move faster so the cold in the rfreezer makes them slow down faster than cold water molecules which are already moving slow, so hence the hot water freezes faster the hot water is "shocked" by the cold as it were.
634368
Low pressure develops when pockets of warm air rise.\n\nHigh pressure develops when air sinks. It is literally pushing down.\n\nAir pressure in general changes due to elevation. The higher up you go, the less air. In turn, there is less air pressure. This is due to the forces of gravity.