In-Stem Flow Regulators

A landscape contractor working on the groundbreaking phase of a new retirement community in Van Nuys, California, had certain specific concerns about irrigation. “Runoff was a very big issue, because there would be seniors walking around, and the owners wanted to make sure the pathways always stayed dry. They couldn’t have any overspray,” explains Eric Watanabe, owner of Signature Pools and Landscape in Granada Hills, California. “We had to make sure that we could really control the water.”

Watanabe had been tapped to work on the project by a landscape architect, whose plan called for installing pressure-regulated sprinkler heads with flow control. However, Watanabe, who has studied advanced hydraulics and has been in the landscape industry for more than 20 years, didn’t think that was the best solution.

As he describes it, pressure-regulated sprinkler heads last for about two years before the mechanism that controls the flow wears out. He had a different idea in mind. “I recommended the in-stem flow regulator (IFR) from Little Valve. I chose this product because of the consistency of the adjustment on it,” he recalls. “You create a controlled chamber inside of the sprinkler that lowers velocity and limits overspray; therefore, you get more uniformity. It moderates the spray coming from a sprinkler head orifice. You set it, and it doesn’t vary.”

The in-stem flow regulator was tested at California Polytechnic University by Dr. Joe Hung (1933-2005), professor emeritus of Agricultural Engineering, and Joe Kissinger, a part-time instructor in the irrigation department. This is the way it works: a hole is drilled into the side of the stem of a sprinkler. A screw is then threaded into that hole, impeding the water flow. By opening or closing the screw, you can adjust the flow rate and even shut it off completely, to service nozzles while the RC valve remains open. Valvette Systems patented the Little Valve.

This component can be used with most major sprinkler systems. The key, though, is that the screw also creates a chamber inside the stem, at the nozzle. That chamber slows the velocity rate of the water coming out of the nozzle, allowing more precise placement of the water.

As the velocity slows, “the water comes through at a controlled pressure,” Watanabe explains. “When that happens, you get zero misting and larger water droplets, which is better for your plant material, your soil and the effectiveness of that sprinkler head.”

It’s also good news for water conservationists, for a couple of reasons.

First, it eliminates misting and fogging and reduces evaporation. Secondly, the water droplets are larger and can be placed precisely, so you can put the water where it needs to be. This amounts to less water used to irrigate the landscape.

Once the landscape architect reviewed the data and saw how IFRs work, she agreed with Watanabe’s suggestion, and an IFR system was installed. The project was set up in two parts, each with a four-man crew. Over the course of four days, 220 heads and seven valves were installed on one part of the project, while 230 heads and eight valves were installed on the other.

The solution worked so well that the landscape contractor who took over maintenance of the property submitted the project to the California Landscape Contractors Association’s (CLCA) annual Trophy Awards beautification competition. The company won first place statewide for small commercial maintenance in 2010, and won again in CLCA’s San Fernando Valley local chapter that same year. It garnered wins again in 2013 and 2014.

But it’s the community that really came out on top. Since the installation of this system, the property has conserved a substantial amount of water, and residents can navigate dry walkways safely and enjoy their outdoor areas—all against the background of a lush, thriving landscape.