Chapin 61813 4-Gallon Lawn/Landscape Pro Backpack Sprayer with Control Flow Valve Technology for Fertilizer, Herbicides and Pesticides, 4-Gallon (1 Sprayer/Package)

This model does not come with a pressure gauge as some of the other models do. It includes an optional flow control valve -- which appears as though it could just be purchased separately and added to any other Chapin (or other brand?) sprayer. The included flow control valve achieves its rated flowrate when the tank is pressurized to 21psi, but other flow control valves can be purchased that give you more or less flow at the given pressure. I performed an initial test of the sprayer with the flow control valve installed and am impressed. When I pressurized the tank and started spraying, the spray pattern and flowrate were very consistent. I stopped pressurizing the tank while still spraying, and the flow cut itself off several seconds later when the pressure dropped below a given amount needed for the flow control valve to work. There was no diminished spray or trickle of liquid -- it just stopped cleanly. When I pumped the sprayer up again, the flow started again. The only con I have with this sprayer is that it seems awkward to hang up for storage. The pump handle doesn't seem to fold up out of the way, and I certainly don't want to unbolt it from the pump whenever I want to store it.

works well, make sure shoulder and waist belts, adjustable straps, are snug and connected otherwise quite a strain on shoulders, easy use to keep pressure up on the fly, while spraying using the left hand lever, obviously for what i used this for i have to say, extreme caution is necessary for going up ladders as i used this to spray roof moss with this unit, google the different mixtures/methods for roof moss, took two fill ups to do the whole roof, moss was starting to become a problem on my asphalt duroid tiles! the caution i mentioned earlier, its a little tricky getting up and off the ladder onto the roof with this, as weighty filled right up, but lasts a lot longer than those little hand helds, which you have to put down to pump up the pressure and refill constantly for larger applications, getting down not so much a problem as i removed the unit from back and carried down ladder with one arm, has adjustable tip for narrow streaming to wide mist, this Chapin 61813 made the application in which i used it, much easier! i would imagine doing lawns/weeds or w.h.y. would be a breeze, did cleanout/rinse after usage, with water through sprayer and tank to maintain, should make this unit last, no regrets on this purchase

Nicely built, works well with the fan nozzle. Pump handle builds enough pressure to work continuesly with slow pumping when spraying large areas. Fits comfortably even when using larger amounts of liquid.

Have to pump it a lot ! Not loving it! Does the job though

Good product.

Sprays like a skunk, even and ready for distruction