Winterizing A Venturi Style Sanitary Yard Hydrant
by Herb Hoeptner
ALL venturi style Sanitary Yard Hydrants require winterizing. No matter which manufacturer makes it, a venturi style sanitary yard hydrant must be winterized. or it will freeze. When one shuts off a common weep hole hydrant, the water drains down the riser and out a weep hole buried in the ground to prevent freezing. This is the concern by most states, regarding cross contamination, for if the water can drain out into the soil, bacteria from the soil can enter the water supply.
When one shuts off a Venturi style Sanitary yard hydrant, the water drains down the riser just like a typical weep hole hydrant, but instead of draining into the ground, it simply drains into a canister or reservoir. When one turns on the sanitary hydrant, the water runs through a venturi or eductor, much like a jet pump, or old style carburetor on cars. When the incoming water runs through the venturi a strong vacuum is formed which sucks the canister empty in preparation for the next cycle when the hydrant is shut off again. Basically, when the hydrant is off, the water drains into the canister and when it is on, the water is sucked out of the canister and water flows out the outlet.
The down side to ALL venturi style sanitary yard hydrants is that when you hook a hose with a pistol grip nozzle to the outlet of the hydrant, and you are hosing down the walkway, when you let go of the pistol grip nozzle the hose will naturally fill with pressurized water. The stand pipe will also fill with pressurized water. Even the tank will fill with pressurized water, waiting for you to use the hose again. If one goes over and shuts the hydrant off, disconnects the hose and puts it away in the barn so it won’t freeze, no water is going to drain into the canister as it has been forced full of water. Water never flowed through the venturi to evacuate the canister. Therefore the hydrant will freeze. To solve this problem one needs to disconnect the hose, turn the hydrant back on for 30 seconds to ensure the canister is empty, and then shut the hydrant off. This will enable the water to drain into the empty tank. It is called winterizing because in the summer one doesn’t care if the hydrant stays full of water. To take this example one step further, let’s suppose one attaches a hose without a pistol grip nozzle. For exaggerated purposes, let’s say the hose is 200 ft long and slightly elevated. The pressure required to push water through 200 ft of hose that is slightly elevated is far and away going to exceed the ability of the venturi inside the canister. The whole hydrant will become fully pressurized in order to push water through 200 ft of hose so again one would need to winterize.
This is generally not a problem when the end user is the same person, for example a private residence or maintenance personnel. Once they are aware of how the hydrant works, winterizing becomes very easy. The problem occurs when the end user is different every other day such as in campgrounds and RV parks. An RV acts just like an overgrown pistol grip nozzle. If no water is flowing through the RV then no water is flowing through the venturi evacuating the tank. Therefore when the RV owner leaves, he disconnects his hose and leaves the hydrant to freeze. It’s no fault of the RV owner, neither he nor anyone else is going to bother to read the instruction sheet or notice the warning on the side of the hydrant. In the past, RV parks have had to overcome this problem by requiring maintenance personnel to winterize each hydrant after the RV owner leaves.
A relatively new type of sanitary yard hydrant, termed the Executive, has been developed at Hoeptner Perfected Products that no longer requires winterizing or ANY end user knowledge. Instead of a venturi, which gets work from the system, it operates on a piston or mechanical device.
When the hydrant is off, the piston moves up creating a void beneath it. The water drains down the standpipe and into the void created by the piston. When the hydrant is turned on, the piston moves back down forcing the water right back up the stand pipe. The beauty to this system is that no winterizing is required, even with a hose and pistol grip nozzle attached. No end user knowledge is ever required. The end user operates the hydrant just like a typical weep hole hydrant, only it’s sanitary. There is no pressure requirement as with the venturi hydrant because the Executive is mechanically operated. A minimum pressure requirement for a venturi hydrant to winterize itself is 20 psi. Minimum pressure for the Executive Hydrant to winterize itself is 0 psi, and it’s fully automatic, no winterizing necessary.
Herb Hoeptner has been designing Yard Hydrants for over 15 years. Five of his thirty-five plus patents are for Yard Hydrants. He has been on the American Society of Sanitary Engineers (ASSE) Working Groups for over 10 years. As a member of the Working Group he helped develop the 1011, 1019, 1052 and 1053 backflow and wall hydrant standards. For the past six years he was chairman of the Working Group to develop the ASSE 1057 Sanitary Yard Hydrant Standard.