GSA Emails Recount Inside Story of Exploding Toilets 119
First time accepted submitter v3rgEz writes "Six months ago, the toilets of the General Services Administration started exploding, injuring two employees and beginning the agency's spiral down the drain of bad press (this is the same GSA now under fire for pricey Vegas conference flings). E-mails just released under FOIA now show the culprit: Compressed air + ancient plumbing + leaving it all unattended."
Re:Bad Press or Bad Behavior? (Score:2, Informative)
Really? Because they aren't perfect, because there are fallible human beings involved?
If that's bothering you, you really should curl into the fetal position because it can happen anywhere. Your plumber, your auto mechanic, the guy who runs the red light, the priest at the local church, anybody anywhere can be up to no good.
And if you think cutting pay will be any thing but a disincentive to honesty, you any want to ask yourself how you'd feel if you got abused into anything.
Rank hypocrisy (Score:5, Informative)
this is the same GSA now under fire for pricey Vegas conference flings
Which is more outrageous than it sounds, because it's the GSA that sets the rates that lots of public institutions use to limit how much their employees can spend for hotel rooms, etc.
Re:So that's why... (Score:3, Informative)
Re:So what? (Score:5, Informative)
No air compressor need be connected to the water system in order to get compressed air in the system.
This [washingtonpost.com] has a better explanation.
Though very rare, it is not unheard of for flush valve water closets to explode. The flush valves need 20+psig to operate, and most codes allow up to 80 psig. Water is, practically, incompressible, so the release of pressure from a suddenly opening valve will create sudden acceleration that may cause "water hammer" and jerk the pipes some. But air is compressible, and if there is air in the pipes, a sudden release of pressure can cause the air to expand explosively, adding much greater acceleration and velocity to the water entering the fixture, and possibly rupturing the brittle ceramics that the fixture is made of.
In most buildings more than a few stories high, you need a pump to raise the water to the top floors and still have enough pressure. Especially in older buildings, this pump is a constant RPM centrifugal pump, which cannot adjust to the variability in flow rates, especially at times of low usage. So the discharge of the pump fills a bladder tank, which contains water on one side of the bladder and air compressed by the water on the other. The pump does not have to turn on and off all the time, because the bladder tank holds enough water and pressure to keep the water flowing for a minute or two after the pump turns off (much longer in times of low flow) and it takes a minute or two for the tank to fill to full pressure while the pump is running ( longer at times of high demand).
Apparently, in this case, the air got into the system because some part of the system failed, the water pressure dropped, and air got sucked in. It was then pressurized by the normal water pressures.
Re:Rank hypocrisy (Score:1, Informative)
Right. Except folks like Neely have the hotel gift them a 2000 sq. ft. suite for booking all the peon attendees at that hotel. Zero cost, so no problem. Cha-ching. Shit went on for years, will continue, and 99% won't ever be caught.
The difference is you're one of the peons that has to follow the rules.
Here is another [washingtonpost.com] 140+ DC city employees fraudulently collecting unemployment while employed. This shit with the GSA isn't surprising; the place is full of corruption [federaltimes.com].
You're either a cynic, a sucker or both.
Re:For the Plumbers in the Audience (Score:4, Informative)
In large buildings you need a pump to move the water to the upper floors with adequate pressure. You don't want to have to wait for the pump to start every time you use water, but you don't want it running all the time even when there is no flow.
So you have a system which consists of water-utility -> pump -> pressure-switch -> pressure-tank -> building-pipes. The pressure take is a take with the inlet/outlet on the bottom. The so long as the pressure-switch reads low enough the pump runs and pushes water into the building— if the building isn't using water it accumulates in the tank. The incoming water compresses air in the top of the tank and eventually the pump turns off. When someone uses water the air expands and pushes the water out. Eventually the pump turns back on until the pressure is back to the set point.
The air is very important in all this— water is almost incompressible if the tank only had water in it then as soon as a faucet was turned on the pressure would fall rapidly. So there needs to be a good amount of air in the take to store energy to push the water until the pump switches back on.
Over time the air can escape from this system— either through leaks in the tank or by dissolving in the water. To fix this someone would connect an air compressor to a fill valve at the top of the pressure tank and pump air back into it.
It sounds like in this case they started it and then forgot about it. Eventually all the water was pushed out of the tank and the system filled up with high pressure air. The pump did not activate because the pressure was still high. Because the air is so compressible it was storing a lot of energy in the pipes. When toilets were flushed this energy was released, rocketing out the small amounts of remaining water at high speed and causing things to blow up.
It sounds like they made an additional mistake of trying to refill the system with water with it closed. This would have just caused the water to repressureize the air wherever it was stuck in the system making for more explosive results. To fix this they should have first opened every thing up that they could before turning the water back on and only allowed the system to go back to normal operating pressure once they had most of the air out of it.
Re:For the Plumbers in the Audience (Score:5, Informative)
Water doesn't flow uphill, and water towers are out of fashion. An unpressurized tank at ground level would just barely dribble out of wide-open faucets on the first floor, at best. And finally, water is non-compressible, itself, so air is used as a propellant.
A water tank typically comes with an air-filled bladder taking up most of the volume. When your well pump kicks-in, water flows into the opposite side of the bladder, compressing the air behind the bladder in the process. When the tank is nearly full, the pump shuts off, and the water is under pressure. This means you have significant water pressure, and more importantly, the well pump doesn't have to turn on to maintain pressure, every single time someone uses a tiny amount of water (otherwise it would burn out the motor in short-order).
There are also (cheaper) bladder-less tank designs, where there's no hard barrier strictly keeping the air and water separate, and those are the ones that most often need to have a compressor hooked-up to them and air added, as a routine maintenance step.
http://inspectapedia.com/water/WaterTankAir2.htm [inspectapedia.com]
Look-up "Hydro-pneumatic tank" if you want to know more about them. If you ever get off of city water, you'll really, really need to.
http://www.highlandtank.com/PressureVessels/Products.asp?ProdID=Hydropneumatic [highlandtank.com]