Automatic fluid delivery systems and methods

A valve assembly for delivering a fluid from an automatic water system to a cage in an animal caging system for housing one or more animals, comprising:

• a valve body and an end cap joined together with a first sealing element therebetween to define distal and proximal portions, respectively, of a fluid channel through the valve assembly;
• and
• a spring element, an interior stem, and a second sealing element disposed within the valve body and the end cap and in the fluid channel to open and close the valve assembly,
• wherein the valve body and the end cap comprise injection molded plastic and are formed with complementary features on their mating ends, said features configured to interlock when the valve body and the end cap are snap fit together, and
• wherein the interior stem comprises an injection molded plastic stem body having an enlarged top portion and an elongated lower portion, and a stainless steel insert pin disposed within the stem body and extending beyond the lower portion, forming a stepped structure whereby a lower surface of the lower portion of the stem body abuts a lower shoulder of the end cap, and only a portion of the stainless steel insert pin is exposed to the cage for actuation by an animal therein.