Hunter HC75F75M — 3/4-Inch Check Valve (Anti-Drain)

What is it and what's it for?

Picture a long hose running downhill: when you shut the tap at the top, the water still inside keeps sliding down by gravity and drips out the other end, even though the tap is already closed. The same thing happens in a sloped irrigation system — the solenoid valve closes up top, but the water left in the pipe keeps flowing down and soaks the lowest sprinkler. This part acts like a kind of 'stopper' installed right at that low sprinkler, and it keeps water from draining or flowing back, even after the rest of the pipe empties out.

Real-world use cases

• At home: Your yard slopes, and you notice that minutes after watering ends, the lowest sprinkler keeps trickling or leaves a puddle — you install this valve at that specific sprinkler and the dripping stops.
• In a business or workshop: A golf course or park with rolling terrain has dozens of sprinklers at different elevations; without this part at the low points, gravity drainage erodes the grass around those heads and wastes water on every single cycle without anyone noticing.

How to avoid buying the wrong one

• It doesn't replace the main solenoid valve — it installs in addition to it, specifically at the lowest sprinkler or section of a sloped zone.
• Confirm the actual elevation change between your system's highest and lowest points: this model holds back 4 to 32 feet depending on how you adjust it with a flat-blade screwdriver.
• The thread is 3/4" female by 3/4" male — measure yours before buying, same as with any threaded fitting in the system.