sure, they're standard in many commercial chicken operations.
I have seen reference to them being operated by gravity pressure only, but I do not know whether this requires specific equipment or can be done with any ol' nipple waterer fittings, sorry.
Hundreds of millions of chickens drink from nipple waterers routinely. They are the standard water delivery system for commercial chicken producers because they deliver clean water with little or no waste.
The way to teach them to drink is simple. Confirm that they have physical access to the nipples. Small chickens may require moving the bucket to inside the Henspa and placing it at the top of the ladder where they can stand on the ladder and reach the nipples.
Birds of a feather flock together. As soon as one chicken "gets it", the other will get it too. You can lead a chicken to water, but you can not make him drink, unless he is thirsty. If the chicken does not get thirsty enough to try everything at his disposal, he may not try the nipple. Giving your chickens water in a pan will keep them from trying the nipples, especially if you routinely give them water at more or less the same time every day. If they have learned that the pan is coming soon, they will wait for it rather than go looking for water from the nipple.
Remember, millions of chickens use nipples. Your chickens are as smart as the rest of the universe and they will "get it" if you do not give them other water sources. How long it takes will very, based on the outside ambient temperature. Chickens drink less water in cold weather and it will take them longer to find the nipples in cool weather that it will in hot weather.
Although chickens can drink from standing water, it is actually harder for them because they do not have any muscles in their throats enabling them to "suck" water into there bodies. They have to place water in their bills and raise their heads enough to allow the water to drain down into their bodies via gravity. Placing nipple waterers at or slightly above eye level grants them the most convenient access to the water.
from
http://attra.ncat.org/attra-pub/poultry_equipment.html (which has more info than anyone could ever want about all the types of poultry waterers in the universe and their pros and cons):
Nipple waterers are standard now in the confinement industry. They are very simple, with a stainless steel trigger sticking straight down from the bottom of the waterer. When a chicken pecks at the trigger, a drop of water rolls down and into the chicken's mouth.
Because they have no bowl, there's nothing to clean. The trigger is self-cleaning because it's washed by the water rolling down it.
Installing nipple waterers is easy; there are kits for gluing adapters to PVC pipe. Many installations use a weird kind of PVC pipe with a square crosssection; others use ordinary half-inch PVC pipe.
Nipple waterers must be set at the correct heighthigh enough for the chickens to peck upwards at them. They are also finicky about water pressure and are not freeze-proof.
I don't like nipple waterers for small-farm work. The payoff is not enough to outweigh persnickity height requirements and pressure adjustments.
Nipple waterers leak sometimes, especially if your water quality isn't perfect. You need more filtering to prevent this. Like other waterers, it's best to use nipple waterers in an environment were wetness under the water doesn't translate to wet litter or wet chickens.
also look at
http://www.ziggity.com/pdf/cont/cont_article_pdf_18.pdf/Solutions_to_the_five_most_common_challenges_found_in_gravity-controlled_water_tanks.pdf.
and
http://www.pointinggundogs.com/2007/05/500_chukar_chicks.html
and you could google more deeply than I did and find more info I'm sure
good luck,
Pat
