Superior 850DI Valve is the Solution to Marin County’s Valve Problem in 1977 California Drought
Richard Greenland of Buckner Superior tells the story of how the Superior 850DI solved Marin County’s valve problem during the 1977 California Drought.
The Superior 850DI valve was introduced following a severe drought in 1976-1977 in California. The hardest hit area during this time was Marin County in Northern California.
Customers served by the Marin County Municipal Water District reduced their water usage by 63% of pre-drought levels. One way they did this was to switch out shrub heads to drip emitters and a lot of home owners complained after the conversion that their valves would no longer close.
The reason the valves would no longer close was because the flow through the valve after the conversion was reduced to a level where there was no pressure loss. If there is no pressure loss, the valves will not close. So, irrigation professionals in Marin County at the time expressed the need for a valve that will close at very low flows. Superior responded with the introduction of the 850DI.
The Superior 850DI has a no minimum flow requirement unlike conventional valves do. The 850DI is a dual chamber valve that consists of an upper and a lower diaphragm chamber. The reason it will close with no minimum flow requirement is no water enters the lower diaphragm chamber while the valve is closing. The only counter force while the valve is closing is from under the seat disc.
The Model 850DI is still used in Marin County today, and many other counties throughout California have adopted this product as their efficient irrigation solution.
What is the 850DI?
The Superior 850DI is a drip irrigation valve. Unlike conventional valves, the 850DI can operate with no minimum flow requirements. Conventional valves require a minimum amount of pressure loss in order to operate properly.
Made of solid red brass construction, this valve is the ideal valve for drip installation use and consists of a dual chamber design that includes an upper and lower diaphragm.
Today, the Superior 850DI is available in both anti-siphon and globe body designs. Both of which includes an atomospheric backflow preventer for applications involving low pressure, low flow, and excessive backpressure. Design allows for complete opening and closing of the valve, regardless of flow rate.