DIY well drilling / trench digging for GSHP

kwfiggatt · 05-31-12, 11:27 AM

Hey folks - the threads on DIY GSHP and well drilling have been great. I am working (very slowly) on my own drilling rig, somewhat similar to Vlad's. I'm using a hydraulic top drive with an inline swivel that I've built myself. These posts have been awesome - thanks so much for everyone sharing the info.

I've noted the problems with pumping grout down the hole to back fill once the loop pipe is in place and wanted to bounce an idea that I've had off of you guys. I was planning on using an old hot water tank (or other pressure tank) that can be filled with grout then air pressure applied from my compressor to force the grout out of the bottom of the tank down the tremie pipe. I'd have to weld fittings on it for the grout outlet and a fill port on the top. It should be able to reach pretty decent pressures (~100psi) for the grout. How deep do you think this kind of pressure would push grout?

I understand the hazards of running with a pressurized tank, and plan on hydrostatically testing the tank to at least 2x my operating pressure before using it - I do not want a bomb!

A pressure pot sandblaster could be used (harbor freight $109 for a 40# model) if you do not want to deal with welding on a pressure vessel.

The only drawback to this type of rig that I see is that it'd require relatively frequent filling of the tank to get the hole full of grout. What do you folks think?

Thanks!

Kevin

05-31-12, 11:27 AM	#11
kwfiggatt Lurking Renovator Join Date: Jan 2011 Location: WV Posts: 1 Thanks: 0 Thanked 0 Times in 0 Posts	pumping grout? Hey folks - the threads on DIY GSHP and well drilling have been great. I am working (very slowly) on my own drilling rig, somewhat similar to Vlad's. I'm using a hydraulic top drive with an inline swivel that I've built myself. These posts have been awesome - thanks so much for everyone sharing the info. I've noted the problems with pumping grout down the hole to back fill once the loop pipe is in place and wanted to bounce an idea that I've had off of you guys. I was planning on using an old hot water tank (or other pressure tank) that can be filled with grout then air pressure applied from my compressor to force the grout out of the bottom of the tank down the tremie pipe. I'd have to weld fittings on it for the grout outlet and a fill port on the top. It should be able to reach pretty decent pressures (~100psi) for the grout. How deep do you think this kind of pressure would push grout? I understand the hazards of running with a pressurized tank, and plan on hydrostatically testing the tank to at least 2x my operating pressure before using it - I do not want a bomb! A pressure pot sandblaster could be used (harbor freight $109 for a 40# model) if you do not want to deal with welding on a pressure vessel. The only drawback to this type of rig that I see is that it'd require relatively frequent filling of the tank to get the hole full of grout. What do you folks think? Thanks! Kevin