Model 625 HD P Gold Hand Dredge Basic.
Includes:
(1) Model 625 HDPPB Pump Body
(1) Discharge Valve Kit (Discharge Valve, MaxiPort Elbow, Turn Key Clamp, Grommet)
Easily passes 1 1/2" solids. Intake port valve is deflector plate protected 3 ply cloth inserted rubber and discharge port valve is Buna-N Rubber..
PVC Plastic. Incredible suctioning power. Achieve suctioning vacuum power in excess of -10 HG with each stroke to lift gold bearing material from where it lays in the streambed.
With a single elongation stroke of the pump, these hand powered suction separator dredges are capeable of creating enormous suction at the nozzle end due to their sealed no leaks construction.
The Model 625 when tested using a in/hg vacuum gage achieved and held a -10 in/hg that's more than 1/3 of an atmosphere. It was equipped with 24" of class 200 1 1/2 in. PVC pipe, yielding 55 cubic inches or 30 1/2 fluid ounces.
1 atmosphere (29.92 inches mercury) = 14.695948775 pounds per square inch
1/3 of 14.695948775 = 4.898
1.71 I.D. /2 = .855r
(.855r x .855r) x 3.14159 (pi) = 2.29658
4.898 psi x 2.29658 sq. in. = 11.24866lbs.
If this calculation is right that 11.2487 lbs.would be a lot of weight that could be held to the end of the 1.71 I.D. nozzle. Compare that to the world famous TV vacuum cleaner commercial that used a 16 pound bowling ball to prove their product and that was with a 6" cone so that created a larger area to apply vacuum over, still experts place the water lift of that vacuum at 65", so the model 625 is twice as powerful.
During the pump down phase that discharges the slurry, the sand, gravel, and gold that was on the way up the hose/pipe looses momentum and might begin to fall back, but a rapid succession of pump strokes will keep it coming virtually walking the larger heavier values up, up and away much like a construction site pump capeable of passing solids. The Model 625 can pump over 25 gallons of water per a minute.
The Model 625 Hand Dredge, works like a typical recreational suction dredge, only the suction is direct, more like a "rocking piston pump" and not dependent upon a weaker power jet venturi that seeks to produce a more constant suction. Best of all, it's ported to easily pass very large 1 1/2" cobbles for when your in a GOLD FEVERED hurry, or accepts the large seive nozzle for suctioning and pumping massive amounts of pre-classified overburden material right through to a free flowing sluice, EGTC or a catch bucket.
Add any of the items from the check list below to get suctioning fast in 1 1/2" class hand powered suction dredging. Some items in the list below have negative values and if selected will "Un-Build" the dredge and reduce the price.