The Irrigation Association recently announced Nelson’s All-Flo PPR (precision plug-resistant) pressure regulator as the winner of the 2020 New Product Contest in the agriculture irrigation category. While the contest is usually held during the annual Irrigation Show and Education Week, this year’s contest was held online.
The Nelson All-Flo pressure regulator has several unique design features that reduce plugging, minimize required inlet pressure and increase accuracy compared to previous designs. It also has increased flow capacity to reduce inventory and installed system cost.
Pressure regulators can be critical to achieving uniform and efficient sprinkler irrigation. Pressure regulators fix a varying inlet pressure to a set outlet pressure to maintain uniform depth of water and chemical application, as well as controlled sprinkler performance. Nelson launched the new All-Flo pressure regulator in late 2020 with the goal of increased capacity, accuracy and reduced plugging.
The All-Flo was designed with a larger-than-normal diaphragm, which means it is more sensitive and responsive to small changes in outlet pressure. This means better accuracy and better uniformity. When a pressure regulator’s diaphragm senses too much outlet inlet pressure, it moves the plunger against a stainless steel spring. Pressure is regulated when the plunger interacts with the seat — as the plunger moves up and down, outlet pressure is adjusted.
The stainless steel springs in Nelson’s pressure regulators are manufactured by Nelson to ensure the actual pressure is as close as possible to the nominal pressure.
A key feature of the All-Flo is reduced plugging. To accomplish this, the offset single-strut seat within the pressure regulator is located out of the direct flow path, minimizing the area in contact with the flow path, as well as any debris that could come through the sprinkler assembly. The seat also has a steep slope, allowing debris to easily slide off it.
Because the seat has been moved out of the way, the plunger has room to be angled at 5 degrees, which also helps minimize the amount of debris that can be caught in the regulator, reducing plugging.
“The angle of the plunger really opens up the flow path. It’s a straighter flow path, so there’s less turbulence, which cuts down on friction loss through the pressure regulator so we get more flow,” explains Gene Ross, vice president of global mechanized irrigation at Nelson. “It’s a wider opening, so if there’s any material in the water, it’s less likely to get caught.”
In addition, the plunger is oversized — with about 52% more area compared to other plungers — resulting in an increased flow capacity.
“We can get more water through the pressure regulator with less friction loss. So it doesn’t require high inlet pressures on the big nozzles on the end of a pivot,” Ross says. “The All-Flo handles our full nozzle range from 6 to 20 [pounds per square inch].”
Having a single unit handle a wide range of flow cuts down on inventory needed in the field — and prevents the confusion that can come with using two different models of pressure regulators on the same pivot. The All-Flo also handles a range of flow capacities — from 0.5 to 20 gallons per minute, reducing the need for a high-flow pressure regulator.
“Often, with longer pivots and/or higher flow rates, you might need more than 12 to 15 gallons per minute out of one nozzle, so you would have to add more sprinklers or go to a high-flow regulator,” Ross says.
The All-Flo requires a minimum of 5 psi over the nominal pressure to maintain an accurate pressure, allowing a lower operating pressure and resulting in reduced pumping costs.
The All-Flo is available on 3⁄4-inch female threads or square thread outlets, and works with Nelson’s 3000 and 3030 series sprinklers. It’s available in nominal pressure ratings ranging from 6, 10, 15, 20, 25, 30, 40 and 50 psi.
“The All-Flo uses the same basic design that goes back a long time, with a rubber diaphragm and metal spring, but with some material, dimensional and architectural changes to add accuracy and capacity and resist plugging,” Ross adds.
Learn more at nelsonirrigation.com.