|
Post by echnaton on Oct 20, 2008 12:35:18 GMT -4
The water heater rocketing up out of the little red shack was pretty good too, IMO. That was one of the funniest Myth Busters explosions I've seen. Way better than the gratuitous demolition of the cement truck. I wonder if they tried different water heaters until they found one that would fail in such a spectacular way. Not very realistic but very funny.
|
|
|
Post by dragonblaster on Oct 20, 2008 13:58:51 GMT -4
Adam Savage could make a tax reminder entertaining. The guy was made for TV. Tory injuring himself with gratuitous irresponsibility is fun as well...
Gee, ain't I a stinker?
|
|
Jason
Pluto
May all your hits be crits
Posts: 5,579
|
Post by Jason on Oct 20, 2008 15:10:36 GMT -4
That was one of the funniest Myth Busters explosions I've seen. Way better than the gratuitous demolition of the cement truck. I wonder if they tried different water heaters until they found one that would fail in such a spectacular way. Not very realistic but very funny. The show did show them blowing up smaller water heaters earlier on, and coming up with the right mix of water and air to make it really go.
|
|
|
Post by echnaton on Oct 20, 2008 15:44:33 GMT -4
It went up because the WH split at the bottom. The smaller one split at a lower pressure in a non-propulsive way. IIRC the big heater had a 50 gallon tank and the narrator said this was a typical water heater. Maybe for California mansions, but around here 35 to 40 gallons is considered sufficient for the typical family. I am just curious if the crew went out and blew up some WHs until they found one that would rocket upwards. Wouldn't that be a fun job.
Enquiring minds want to know.
Anyway, as long as a WH is connected to the water mains, the pressure inside can't rise above the line pressure, at least the way WHs are hooked up here. So anyone taking a bath would note have to worry about an explosion even if the heating element was stuck on. Areas that have pressure regulators on the incoming lines might have more concern.
|
|
|
Post by PhantomWolf on Oct 20, 2008 15:48:52 GMT -4
It went up because the WH split at the bottom. The smaller one split at a lower pressure in a non-propulsive way. IIRC the big heater had a 50 gallon tank and the narrator said this was a typical water heater. Maybe for California mansions, but around here 35 to 40 gallons is considered sufficient for the typical family. I am just curious if the crew went out and blew up some WHs until they found one that would rocket upwards. Wouldn't that be a fun job. Enquiring minds want to know. Anyway, as long as a WH is connected to the water mains, the pressure inside can't rise above the line pressure, at least the way WHs are hooked up here. So anyone taking a bath would note have to worry about an explosion even if the heating element was stuck on. Areas that have pressure regulators on the incoming lines might have more concern. As long as you have the saftey equipment in good nick there isn't too much of an issue, but this one is no myth
|
|
raven
Jupiter
That ain't Earth, kiddies.
Posts: 509
|
Post by raven on Oct 20, 2008 16:17:22 GMT -4
Call me nuts, But that myth testing and the final 'test' of the gunpowder concrete removal myth are my favorites. Funkaroonie, I am glad no one lived in that house.
|
|
|
Post by PhantomWolf on Oct 20, 2008 16:44:42 GMT -4
Certainly looks like it's a case of old and damaged equipment that is the issue. Making sure that yours has all the right features and is well looked after shouldn't create a rocket in your house.
|
|
|
Post by PhantomWolf on Oct 20, 2008 16:46:42 GMT -4
|
|
raven
Jupiter
That ain't Earth, kiddies.
Posts: 509
|
Post by raven on Oct 20, 2008 17:12:23 GMT -4
Just goes to show you the immense energy that is bound up in vaporised Dihydrogen Monoxide.
|
|
Jason
Pluto
May all your hits be crits
Posts: 5,579
|
Post by Jason on Oct 20, 2008 18:17:20 GMT -4
It went up because the WH split at the bottom. The smaller one split at a lower pressure in a non-propulsive way. IIRC the big heater had a 50 gallon tank and the narrator said this was a typical water heater. Maybe for California mansions, but around here 35 to 40 gallons is considered sufficient for the typical family. 50 gallons is not unusual. I have seen 60 gallon heaters in larger homes, but new build houses around here usually have two 35-40 gallon heaters instead (one for each floor, typically). Earlier in the show they experimented with smaller heaters full of water that just ruptured rather than rocketing. I'm no plumber, but I understand that most WH connections have a backflow limiter which would prevent water from the heater from going back into the general water lines (to prevent contamination of the general water supply from rust, sediment, or other nastiness that might be in any particular heater), so being hooked up to the mains will not allow the heater to relieve pressure by venting into the main water lines unless the backflow preventer fails. The real safety measure is the temperature and pressure release valve, which opens if things get too hot in the heater. In the Mythbusters episode they mention that some people apparently have capped the line off their pressure release valve, thinking it wasn't doing anything worthwhile. Big mistake. Hot water heaters here in Utah also have to have supports on them to keep them upright in case of an Earthquake.
|
|
|
Post by echnaton on Oct 20, 2008 21:01:43 GMT -4
I'm no plumber, but I understand that most WH connections have a backflow limiter
I don't think mine does, and that is what I was basing my statement on. AFAIK,we are only required to have backflow preventers on lawn irrigation systems.
The unoccupied house mentioned in the link may have had the water shut off at the meter, preventing the pressure in the WH from backing water out into the mains. I am surprised that the faucets would not leak away the excess pressure before the heater exploded.
|
|
|
Post by PhantomWolf on Oct 20, 2008 21:21:55 GMT -4
Well just for you echnaton.... This one was in an occupied home just 3 months ago.
|
|
|
Post by echnaton on Oct 20, 2008 21:28:09 GMT -4
I wouldn't have though that exploding WHs were that common.
|
|
|
Post by frenat on Oct 20, 2008 22:16:36 GMT -4
It went up because the WH split at the bottom. The smaller one split at a lower pressure in a non-propulsive way. IIRC the big heater had a 50 gallon tank and the narrator said this was a typical water heater. Maybe for California mansions, but around here 35 to 40 gallons is considered sufficient for the typical family. 50 gallons is not unusual. I have seen 60 gallon heaters in larger homes, but new build houses around here usually have two 35-40 gallon heaters instead (one for each floor, typically). Years ago my parents installed a 120 gallon water heater. This was in an 1800 square foot 4 bedroom home in Ohio. It saves money though because it only heats during off peak hours so the electric company gives a discount. The heater needs to be larger to they don't run out of hot water during the day.
|
|
Bob B.
Bob the Excel Guru?
Posts: 3,072
|
Post by Bob B. on Oct 21, 2008 11:03:24 GMT -4
I'm no plumber, but I understand that most WH connections have a backflow limiter I don't think mine does, and that is what I was basing my statement on. AFAIK,we are only required to have backflow preventers on lawn irrigation systems. Backflow preventers are commonly used in industrial applications where potable and non-potable water systems must be kept isolated from each other. Backflow preventers are also used on fire protection systems, spinkler systems, etc. I can't recall ever seeing a backflow preventer in a residence, though exterior hose bibbs often include an anti-siphon breaker. It's possible water heaters may have a built in backflow device - I really don't know - but it is not typical to have the whole house so protected.
|
|