CFM requirements to push a pull string

Cow

Senior Member
Location
Eastern Oregon
Also found one should install the pull line ASAP after installing underground raceways even if not intending to pull conductors right away. Condensation or any other reason to have water in the line makes blowing a line in more difficult if you wait too long and this water has accumulated.
I agree. We do wait a day for string installation on long runs though.

A few years ago, we had a 1000' run of 4" that had a measuring string installed right after conduit installation. A couple days later we went to pull the rope in and we found the measuring string was stuck, from excess glue oozing through some of the joints into the conduit.
 

roger

Moderator
Staff member
Location
Fl
Occupation
Electrician
I had a thomas jet line which is a bottle of compressed gas for blowing lines.
The greenlee line vac was overall the best, but of course needs power, it was much better than a shop vac, it could blow or vacuum.
A generator and vac would work.
A CO2 tank is what we always used too. They can be dangerous though, at one company I worked for we had a guy pull the trigger without having hold of end of the hose and lost an eye.


Roger
 

ptonsparky

Senior Member
Location
NE (9.06 miles @5.9 Degrees from Winged Horses)
Occupation
Electrical Contractor
A CO2 tank is what we always used too. They can be dangerous though, at one company I worked for we had a guy pull the trigger without having hold of end of the hose and lost an eye.


Roger
CO2 makes one heck of a mess if the pipe has mud or water in it and can put the mouse through one side of a hollow core door.
 

roger

Moderator
Staff member
Location
Fl
Occupation
Electrician
CO2 makes one heck of a mess if the pipe has mud or water in it and can put the mouse through one side of a hollow core door.
Yes it can but normally it only takes once to learn it. ;) It can also put an old style scotch red wire nut into orbit.

Roger
 

kwired

Electron manager
Location
NE Nebraska
HVAC guys were purging/pressure testing their system in a school - larger bank of compressors that supplied several room modules all on one refrigeration circuit. they had over 100PSI in the system already when a pro-press fitting that never got crimped finally let go. I was across the gym and in another area, was really loud and still scared the hell out of me at the distance I was from it. School maintenance man was pretty close to it though...
 
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