You are using an out of date browser. It may not display this or other websites correctly. You should upgrade or use an alternative browser.
vacuum
A vacuum is a space devoid of matter. The word is derived from the Latin adjective vacuus for "vacant" or "void". An approximation to such vacuum is a region with a gaseous pressure much less than atmospheric pressure. Physicists often discuss ideal test results that would occur in a perfect vacuum, which they sometimes simply call "vacuum" or free space, and use the term partial vacuum to refer to an actual imperfect vacuum as one might have in a laboratory or in space. In engineering and applied physics on the other hand, vacuum refers to any space in which the pressure is considerably lower than atmospheric pressure. The Latin term in vacuo is used to describe an object that is surrounded by a vacuum.
The quality of a partial vacuum refers to how closely it approaches a perfect vacuum. Other things equal, lower gas pressure means higher-quality vacuum. For example, a typical vacuum cleaner produces enough suction to reduce air pressure by around 20%. But higher-quality vacuums are possible. Ultra-high vacuum chambers, common in chemistry, physics, and engineering, operate below one trillionth (10−12) of atmospheric pressure (100 nPa), and can reach around 100 particles/cm3. Outer space is an even higher-quality vacuum, with the equivalent of just a few hydrogen atoms per cubic meter on average in intergalactic space.Vacuum has been a frequent topic of philosophical debate since ancient Greek times, but was not studied empirically until the 17th century. Evangelista Torricelli produced the first laboratory vacuum in 1643, and other experimental techniques were developed as a result of his theories of atmospheric pressure. A Torricellian vacuum is created by filling a tall glass container closed at one end with mercury, and then inverting it in a bowl to contain the mercury (see below).Vacuum became a valuable industrial tool in the 20th century with the introduction of incandescent light bulbs and vacuum tubes, and a wide array of vacuum technologies has since become available. The development of human spaceflight has raised interest in the impact of vacuum on human health, and on life forms in general.
Need to adjust some pipework for new radiator but both the branches for old radiator came off the same pipe. Will this create a vacuum for me to move the tees further apart then rejoin up?
Powerful cordless 2-in-1 Air Duster & Vacuum
The Dusta Duo 2-in-1 Air Duster & Vacuum features a super powerful 60,000 rpm motor and creates a wind speed of over 35m/s. With its compact size. The Dusta Duo can effectively remove dust from almost anywhere.
It can also be switched from a blower...
Hi anybody worked on vacuum solar I have a 30 tube panel piped up correctly sensors and pumps correct but I cannot get the panels to produce any heat above 26 oC they are about 8 yrs old and I was informed they have never worked properly .It feels like they are not transferring heat through the...
Before I say anything else, I want to make it clear I do not hold an asbestos qualification and I refuse to touch the stuff professionally.
However, my father said he'd pay for me to buy the vacuum cleaner as I need to take up some old asbestos Marley tiles and probably remove some Artex (I've...
Good Morning Engineers,
I have a Worcester Greenstar open vented boiler, feeding rads and hot water system via a 3 port motorised valve. I live in a bungalow, and all pump/valve/control systems are in the roof - boiler down stairs. I need to replace the 3 port motorised valve, but do not want to...
Hi All, I've got a Oil Fired Rayburn to service in an 'off grid' house - no electricity. Does anyone have any recommendations for a cordless vacuum for clearing all the soot out? cheers
H guys.
I'm about to buy the bosch wet and dry vacuum cleaner £200.
Small compact ideal for me.
Anyone know or recommend really good wet and dry vacuum with a good blow function.
As the Bosch GAS 20L SFC Is an astoundingly £200 and has a 5* rating - but only by one buyers feedback...
Just wondering who uses a wet vac these days. Some of my friends are still connecting mains outlets by hoses for air locks and draining rads with Tupperware lol
Just want to clear this up.
Just finished my oftec training at Grant. One thing they wouldn't really cover was how to test the oil supply for blockages/ leaks using a vacuum gauge. Very annoying as I like to learn as much as. I also done the burner course, vortex and Combi courses in Jan and it...
What is a very good quality wet vac? Had a Wickes one at about £40 and a Karcher one at £200, both spew out water. I don't mind paying good money for a good product.
Our 15-year-old Aquastream Aqualisa power shower has recently become really noisy, like a vacuum cleaner. Does this mean the pump is on its way out, or are there any other possible explanations?
I'd rather not replace it right now because my boiler will probably have to be replaced in the...
paralucent
Thread
aqualisa
cleaner
power
power shower
shower
sounds
vacuum
Am I the only one who thinks this is f****** bonkers?? So instead of us being able to buy 2100W vacuum cleaners we can now only buy 1400W vacuum cleaners. This will of course save electricity the world round except cleaning with them will now take 50% longer. The result? Oh yes, the same...
I have a george vac but with it only able to take 9ltr of water I was gonna get the performance power one from b&q tomorrow morning.
Question is, if I'm not careful when filling it up, will it pour mucky water over the carpet from every orifice when full?
The george has a non return ball valve...
Any recommendations? Im looking for a vacuum to clean up deposits brushed from heat exchangers in domestic gas boilers. I assume given the potential for carcinogens in the deposits or potential for asbestos fibres in some older boilers that it should idealy be at least hepa filtered. I dont know...
Does anyone here know anything about vacuum drainage systems?
I live on a boat and there are about 60 other boats on the mooring, most of us using the vacuum drainage system with varying different aged installations.
I was asked to look at one which had stopped working and managed to get it...
Sure, ad-blocking software does a great job at blocking ads, but it also blocks useful features of our website. For the best site experience please disable your AdBlocker.