atcomsystems.ca/forum Forums Wiring - Telecom Carriers - Trunks & Services Cabling Telephones Systems Wiring Best conduit blowing solution?

New to the group - hello! I have a large project that requires a lot of conduit pulls - more than I'm used to - and instead of the trusty fish tape I am considering using a jetline or compressed air line blower. I'd like to know if anyone in the group has suggestions for such a device and some idea of price range? The conduits don't exceed 1000 feet and are 1/2 and 3/4 inch. I'll be pulling mostly z-wire with occasional Cat-5e.
Thanks for your responses.
K

Conduit blowers and accessories are very expensive. I've had the best luck with a very high-quality shop vac, jet line and plastic bags. I have a full conduit blowing rig but it rarely gets used because the shop vac is so much more effective.

I just tie the bag onto the end of the the string in "bow tie" fashion and stuff it into the pipe. The trick is to suck the line through, not to blow it. That is where you lose a lot of power.

For larger conduits, just use trash bags as your bow tie. You'll be surprised how well this works. Just remember: Never try to blow the line through.

Hi Thanks for your reply - good suggestion! So, what constitutes a very high quality shop vac? Are there certain specs to look for? What about attaching the hose to the pipe?

K

You'll probably want to get a vac that has wheels and decent storage for accessories. You'll also want a unit with good horsepower, so your wallet will dictate that part.

As for the fittings to adapt to pipe, a trip down the plumbing aisle at your local home center will put your mind to work. I got a PVC adapter that goes from 2" to a 3/4" male thread (you'll probably need to put several fittings together since these are rare). Then, I got a washing machine water hose to screw onto the end of it. I cut off the other end of the hose and it fits in 1/2" and 3/4" conduits well. You can seal the entrance into the conduit with your hand or just a wet cloth.

No doubt, you'll want to practice this and learn your way through the process.

Greenlee makes a shop-vac that comes with all the accessories to suck pull line through pipe. I've used them successfully on numerous jobs.

Years ago I ran a very large job with thousands of cable pulls all going through conduit (at least part of the way). We tried a vacuum first and had some troubles. I had better luck with jetline. One of the larger electrical supply houses in the area rented us all the equipment we needed - which wan't much. We got one large tank of compressed air and two smaller portable tanks that we would refill from the large tank. When the large tank ran out they would haul it out and bring us a new one.

We used jetline "shots", those little tubes of very strong nylon in the correct size for the pipe. I would go around and mark all the outlets with the correct cable number and the "gas bottle" crew would mark the number on the shot and shoot it through the conduit. Another crew followed behind them, using the shot to pull in regular strength jetline and then a third crew pulled the cable in with that. It worked fine. Better then fine.

Sam

I'm with Ed, maybe because I've never had a job of the size Sam described. There is one thing that the jetline won't do. Go Through A Box and out the right conduit. A vacuum will suck it through every time, IF you temporarily plug the other conduit(s). And more than 1 in, 2 out of the box is where you call the electrician back, because it ain't gonna work, even if he puts in pull strings as he goes. It WILL twist and tangle!

Been there, done that with both methods...the cleanest is the vacuum.

If you blow it can push water and mud out into the finish area. I have seen a geyser come out the other end...not nice.

Greenlee is great but pricey. Sears used to make a 30 gal twin motor wet/dry vac on rollers that worked good with the small cone-shaped nozzle that fits the smaller conduits.

Like was stated above...check out renting from a supply house or subbing to a sparkie for your lines to be placed.

Good luck.

I use a 5hp Rigid shop vac

like Ed said I carry various PVC ells and reducers , that and Duct tape works for me

like ken said there may be water and other debris so I let the vacuum suck for a few minutes before feeding the string

Useful and informative - thanks to all for your responses.

The best way I have found to adapt a vac. hose to conduit (over an 1 1/2") is a small road cone. Just stick the road cone cone into the conduit until its tight then stick the hose in the bottom. Thought I would share.