What are the two things in front of the house?
lily88
| Posted in Construction Techniques on
There are two strange things(utilities?) in front of a house. Who know what they are?
Will they bring some trouble to the residents in the house?
Thanks
Replies
I'm guessing they belong to some sort of lift pump arrangement in a manhole there. One is a simple vent, and the other is the outlet of the lift pump. This could be protecting a utility vault, or it could be some sort of sewer pump for cases where the sewer system is overloaded.
(Or, if you prefer, those are radio antennas for a secret CIA listening post. The smaller pipe is in that J shape so that black helicopters can moor there while they hover overhead.)
update - I have gotten partial answer from city hall
update: I have get partial answer form city hall. They told me they belong to the "PRV(pressure release valve) station" which are managed by city. They are relative with water. But they don't know if the water in the equipment is only from rain water or only from durty domestic sewage or from both.
How do you think about the possibility? The system are built in 1989.
BTW, Thank for Calvin's suggestion. I will keep in mind. Also thanks for DanH's help.
Thanks
If it's a "pressure release
If it's a "pressure release valve" it could actually be for the water main, to release pressure in certain circumstances. This would be especiallly likely if your city water supply comes from some distance via an aquaduct of sorts -- a sudden drop in water usage could produce a surge of pressure, and this valve would help prevent damage to mains and household plumbing due to the high pressure.
If there's a pump below there would almost certainly be an electrical service box of some sort (at least a 10x20x20 metal box on a short pillar) somewhere nearby in the bushes. A "passive" pressure release valve, on the other hand, would need no electrical supply.
Lilly
You made two additional posts, one was deleted-it had no responses.
The other is on the board with a couple responses.
Now you made this post which will stay as it too has a reply.
Please don't make another thread on the same subject-it gets too hard for us to make replies and see prior replies and you too, as you'll be having trouble finding an answer.
thanks.
Unfortunately it is confusing, especially to newbies, since this excellent web site sends the user back through the "post" screen after posting, if they use the "back" button (which is only natural to do). Many times people think the post didn't "take" and press "post" again, resulting in the double post.
yes, it is confusing.
With these 2 posts hours apart, the double click backspace thing wasn't the culprit. I think she couldn't find nor did she look very hard for the original. If entering at Recent Replies, then that could have done it. You won't find a thread there very easy-maybe a response if you look close.
But what the heck do I know-I'm just a dumb carpenter with a 2lb. hammer.
Actually, only 10 minutes apart. Fairly easy to spend that long trying to comprehend the "posted" screen, then paging back and wondering if one should press "post" again.
Who know what they are
me, me, me
those is pipes! The white one is a threaded pipe with a 180 degree return bend,
the other is a classic example of 3 different types of pipe joining methods, welded, flanged, and threaded.
This was a tech school vocational project for pipefitting.
All kidding aside, there was an old thread with the person wondering what the buried wire in with the lawn sprinkle system was, got lots of answers. The op finally dug the length of the wire and determined it was either simply the tracer wire for the plastic piping, or some scrap wire thrown in the trench for disposal.
Well, no shit.
of course it was a locator wire-what else would it be running with a plastic pipe?
Air vents for the water line.
They appear to be the vent lines from an air/vacume/air relief valve, that is part of a water main.
The AVAR valve is installed at high points on water lines to let any trapped air out, so you don't get an air blockage. They also allow air to enter the pipe if it is being drained to prevent vacume from collapsing the pipe.
The valve has two different air vent sizes. There is a large one that lets out air as the pipe is filled or drained, and a small one to release the air that comes out of solution or suspension in the water.
If you want to know more, go here: http://www.valmatic.com/brochures/Air_1500.pdf
Thanks a lot!
Will look at the website. ....
It should also be mentioned that the two pipes may be unrelated to each other. Pipes such as the first, small one are often seen where gas mains run, though I've never quite figured out their purpose. (Possibly a vent for a pressure regulator?) The second, larger pipe is definitely for water or drainage of some sort, though.
I'm skeptical that it's a air valve. The larger pipe is clearly designed to let water out (and send it down a drain to somewhere).
Yes they do collapse
Seen it, Fixed it.
Pipes work on hoop strength to resist expansion. The greater teh internal pressure, the rounder they want to get.
If there is the least bit of anything pushing on it from the outside, when the vacuum is applied, they collapse.
But underground pipe must resist the force of the soil and other applied loads above it. And those forces can be well in excess of one atmosphere, and non-uniform to boot.
I understand hoop strength, but there's no way that even a perfect vacuum can exert the pressure needed to crush schedule 40 iron pipe, which those obviously are.
Maybe you're thinking that the pipes below are something less robust, but I can't imagine what they would be.
The Sched 40 is above ground.
We have no solid knowledge of what is below ground, and I have seen what appeared to be properly bedded pipes that have been collapsed.
And we aren't just worried about the atmospheric pressure. If the Pressure Reducing Valve, (PRV) is running full open and closes too rapidly because someone set it up wrong, you end up with a hydraulic ram. Depending on the pipe diameter the forces are quite substantial and can collapse the pipe. The AVAR, allows air entry in such cases, and then since AVARs are typically at a high point will allow the air to bleed back out. A properly specified and installed, AVAR has orifice sizes selected to minimize the hydraulic ram by letting in just enough air to dampen it and prevent sufficient negative pressures to collapse the pipe.
I'm sorry, but no matter how powerful the ram force, the pressure on the pipe cannot exceed one atmosphere, plus the pressure from the soil.
I could see this being a problem for large diameter pipe -- over 3 feet or so -- but the the pipes below are certainly smaller than that, and can easily withstand 14.7psi.
Exactly ritght.
This is another urban legend that gets credence because it sounds reasonable to assume that huge ram forces might produce equally huge vacuum forces.
There was a local TV ad here a few years ago that showed the owner of a restoration/cleaning company sitting at his desk showing a 3/8" copper supply tube--the kind used for a toilet supply--and professorially explaining how such tubes collapse when the water supply temporarily loses pressure. (The tube shown had not collapsed, BTW.)
deleted
My post was listed as reply to the OP, even though I clicked to reply to one of the responses--bah!!