• If you use a bulk truck, the compressor for it’s brake system can be an ideal choice, because it will normally be where you need to dewater.
• Obviously, the air used with the drilling equipment will serve this purpose, as long as the drill is in the area.
• A spare haul truck with a air brake system can be parked at the edge of the drill pattern while air is drawn from its’ receiver tank.
• The compressors found in a field mechanics truck or in the tire service truck are also adequate.
• Some operations keep a small portable gas engine compressor on hand as a dedicated air source for this use. Continued access to one of these units allows the loading crew the flexibility to contin ue dewatering, when other sources aren't available.

THE PRESSURE REGULATOR
Compressors, such as those described above that are commonly available at a blast site, usually furnish air at about 125 psi. That pressure level is more than is necessary, and is above the safe levelneeded to dewater blastholes with this system. A pressure regulator, such as the one which is furnished with the pump, is designed to reduce the pressure down to a level where it will lift the water from the hole efficiently, but remain below the level which will damage the pump or the operator. To adjust the pressure on a typical regulator, loosen the lock nut on the shaft which secures the tee handle, turn this handle in (clockwise) to raise the pressure. Bring air to the regulator and make your initial adjustment before pumping. 50 PSI is a good starting point, (see the next paragraph). Make final adjustments as the unit is pumping and the air is moving. Note the pressure level when a good flow of water is being removed from the bottom of your deepest hole. That level should serve as the highest pressure you would need from then on. Check the gauge periodically to be sure higher pressures are not being used.

SOME QUICK PHYSICS....
Pressurized air is an efficient way to lift water, but like every other process, it does have limitations. The key numbers to remember: One pound per square inch (psi) of pressure equals 2.31 feet of head, (or lift). In other words, 10 psi of pressure below the sleeve will force the water up the discharge hose about 23 ft[7m], (10 times 2.31). 50 psi in a drill hole would lift the water in a hose about 115 ft[35m], (50 times 2.31), but you wouldn't have any flow from the line at that pressure in a hole that deep. You would get a lot of flow from that depth however, with 60 or 70 PSI. As a practical matter, the sleeves for this system require a minimum of about 40 psi to inflate them solidly against the wall of the hole. So with the regulator set a bit above that level, any hole down to a depth of about 80 feet, (25m) will be efficiently dewatered with this system. With the normal sleeves we produce, we think their practical limit is reached when pressures approach 90 PSI. That level of air pres sure will raise water into your discharge line a bit more than 200 ft[61m], assuming a good seal against the wall with minimum air bypass, and will adequately dewater holes approaching 175 ft[23m] deep. A compressor capable of delivering at least 15 CFM at 100 PSI would be necessary in order to pump efficiently from those depths.

ANSWERS TO COMMON QUESTIONS:

Q: How long do the sleeves last?
A: The replaceable sleeves, which are the only wear items on the pumps, last anywhere from several weeks to several months. Their useful life is mostly dependant upon the degree of roughness of the wall of the drill hole.

Q: Will it work in rough or soft ground?
A: The pumps seem to work well and seal in any hole from which the drillers can blow the cuttings. The pump isn't recommended in extremely soft ground or overburden that's drilled with an auger or drag bit.

Q: How do I keep the pump from getting stuck?
A: For holes with rough, loose collars, a short collar saver tube is provided. It should be used to prevent material from falling in the hole and trapping the pump. A 3/16" braided stainless wire cable is offered with each new pump as an option. This cable can aid in retrieving the pump should it become lodged by a loose rock.

Q: What size is right for my holes?
A: Go to the button on the left that reads “product description’ for those details.