Fibertec Banner
 
 Register  Login   
Welcome to GreenBuildingTalk - the place to share, ask and learn about green building products and methods. While you can browse the site as a guest, you need to register in order to post. Registration is fast, simple and free so join our community today.
Find a Green Building Pro 
Browse Project Albums 
View Product Guide 
Unanswered Active Topics
Forums Search Members
Forums > Green Building Technologies > Geothermal Heat Pumps > Subject: Horizontal slinky on small lot

You are not authorized to post a reply.   
Prev Next
Page 2 of 2 << < 12
Author Messages
esgerUser is Offline
Registered Users

Posts:20




06/21/2008 7:06 PM  
The pipe is HDPE SDR11
cnygeoUser is Offline
Registered Users

Posts:68




06/22/2008 9:40 AM  
Tough call. As your contractor said the pipe is pretty tough and will take a lot of abuse. On the other hand, you really don't want to be digging it up again. The kink shoudn't restrict flow to any significant degree, but it will be a weak spot that could compromise it over time as it expands and contracts. How did you decide to do your manifolds? If you're doing outdoor manifolds and having them fusion welded, I'd probably cut out the kink and weld it just for piece of mind if you've already got the equipment. As for the scratches from the bucket, impossible to tell without knowing how bad the buried sections are. Is only one pipe losing pressure? When you pressurize the pipe, it will stretch slightly and lose a bit of pressure. Are you pressurizing it with water or air?

If you're still hoping to do without antifreeze, I'd say a small leak might be tolerable, though certainly not desireable, depending on how you define small. I would be concerned about it getting worse with time. If you ever did need to add antifreeze, even a small leak would be unacceptable in my opinion.

Discalimer: I'm basing this on my vast personal experience of installing one system - one of the pros would undoubtedly have better advice.
esgerUser is Offline
Registered Users

Posts:20




06/22/2008 1:32 PM  

Cyngeo,

We are doing indoor manifolds.  The pipe is being pressurized with air and each pipe has an individual valve connected to a common pressure gage.  Yesterday, we talked to the gas man who was testing the soil around our gas line the excavator had broken, and he said the crimp did not look too bad.  He suggested that we put a stainless pipe repair clamp around that section to stabilize expansion and contraction and reduce stress.  It would also help make sure the pipe does not re-crimp at that section as we lay the rest of the pipe.

I have bought some sheet plastic to create a water pond so I can drop the whole pressure testing manifold under water to see if I spot a slow leak that is not showing with soapy just water.  The excavator also ran over a section of pipe that was well out of his way when he was not paying attention (he also ran over a 7’ tall by 6’ diameter rhododendron which we were sad to lose and he ran into our the corner of our metal shed crushing a corner.)  I will test that section by submersing it too.  That section is not buried, but, while it had maybe quarter inch deep dents in it from the track hoe tracks, within an hour or so, it had returned to normal shape and you could only see scratches. 

As to the antifreeze issue, I never meant to imply that we would not use it, only that the system is expected not to go below freezing in the loops.  We will be using antifreeze.

An additional note about gas line safety:  I had the gas line clearly marked by the gas company at the excavator's request, but it turned out to be about 12” inches from where they thought it might be.  The excavator was trying to save a little time and effort by digging with his track hoe as close to the pipe as possible before hand digging, and he tore the pipe right out of the ground.  The supply side had sheared flush below the ground, so the excavator decided to bury the severed end to try stop the gas flow.  Apparently, that is the worst thing one can do – the ground can fill up with gas and create a giant underground bomb.  You should just clear away (the excavator continued to dig the trench), not try to stop the leak, and let the gas dissipate into the air. 

Also, while the excavator had several clauses in his contract about not being responsible for locating and damage to underground utilities, Oregon contractor's law says he is exclusively responsible for both locating and the cost of damages.  Apparently, he is also responsible for incidental property damage, despite any clauses in his contract to the contrary. 

AltonUser is Offline
Registered Users

Posts:307




06/22/2008 2:38 PM  

esger,

Please tell us that the excavator is no longer on your property.  You have much more patience than I.


Alton C. Keown
Residential Designer and Construction Technology Consultant
Auburn, Alabama
334 329-0957 AT&T Cellular
geodeanUser is Offline
Registered Users

Posts:583





06/22/2008 2:49 PM  
Brint.

Sorry to hear of your troubles.  It sounds like the excavator is really a loose cannon.    He should be reported for his dangerous gas line handling.  We had several homes in our area completely destroyed and people killed when a gas line was cut and the gas migrated underground into nearby homes.

We always test with water since this makes it really easy to know if there is a leak.  Since air can be compressed and water can not,  it will take a long time for the air pressure to drop very much where as with water you will know right away if there is a problem.  

I have attached a testing procedure that will guide you through the process.  Use a target pressure of 125 psi.

HDPE pipe while not indestructible,  it will take some abuse and still perform as needed.  It sounds like you will be OK.  Especially if it passes the test since system pressure doesn't need to higher than 40 psi and you will be testing at 125 psi.

Hope this helps


(the attachement is to large)

email me and I will send it to you

dean at palacegeothermal.com

Dewayne Dean
PalaceGeothermal.com
Why settle for 90% when you can have 400%
We heat and cool with dirt!
visit- http://welserver.com/WEL0114/- to see my system
You are not authorized to post a reply.
Page 2 of 2 << < 12

Forums > Green Building Technologies > Geothermal Heat Pumps > Horizontal slinky on small lot



ActiveForums 3.6

Professionals Serving
Your Location:

Creative Panels (Kingsburg, CA)
Amvic-Pacific (Nevada City, CA)
Sierra SIPs (San Andreas, CA)
Blue Lupin Developments (Incline Village, NV)
Greenblock Worldwide Corp (Cave Creek, AZ)
View More

GBT Project Albums:

Off-the-grid home (E of Eganville, ON)
Jay's House (Burlington, VT)
MN Geothermal Retrofit (Twin Cities, MN)
Kitchen/gathering room (Manchester, MI)
Out with the old (Fort Ashby, WV)
More Info |  Search
Copyright 2008 by BuildCentral, Inc.   Terms Of Use  Privacy Statement