Fill and Drain (GROmaster) valve
Image 1 - Drain Valve
Image 2 - Water Supply Line
Image 4 - Water and Drain Line
The fill and drain valve (GROmaster valve) used for EBB-FLO® flood benches saves time and only requires the use of one hose.
Water enters from one end of the valve and goes throught the hose, filling the EBB-FLO® flood bench. Once the bench is filled, the water returns through the hose and drains through the bottom of the "T" fitting into the gravity drain line. The drain from the fill and drain valve must have an open connection, or it will not operate correctly. See image 1.
Image 2 shows the water supply line (pressurized supply from pump at main holding tank). When the controller applies power to the solenoid valve, it opens and water flows through the valve and hose to the EBB-FLO® bench. When the solenoid valve is turned off, the water drains back from the bench and through the drain line, returning to the holding tank.
Image 3 shows the typical installation of the GROmaster valve under an EBB-FLO® flood bench. The main drain, fill lines, solenoid valve and GROmaster valve assemblies should be located approximately 4 feet back from the end of the EBB-FLO® flood bench where plumbing connections are made. The hose connecting the GROmaster valve should hang loosely so there is no strain on the connection to the EBB-FLO® flood bench. The connection to the EBB-FLO® flood bench is made with a fitting provided through a hole in the plumbing well of the EBB-FLO® tray. The fitting is made with a 1-5/16" hole saw, should be tight, and made with the rubber gasket on top of the bench. The screen provided is inserted at the top of the connection fitting, and the bench filter (stainless steel screen) is placed over the plumbing well.
The fill (pressurized line) can be a 1", 11/2" or 2" PVC pipe, depending on the size of the installation. The typical PVC pipe is 11/2".
The gravity drain line is typically a 3" or 4" PVC pipe. The stub under each bench where the GROmaster valve drains is typically a 2" PVC pipe.
The solenoid valve and the fill and drain valve are all 1" pipe. The union shown in the pictures is not required, but is recommended for ease in future repiars. NOTE: If the greenhouse is not heated through winter and may freeze, it is best to locate the union on the inlet side of the solenoid valve. This gives ease to disconnect the plumbing and drain the system before the cold temperatures.
Image 4 shows the water line and drain line of a GROmaster valve installation at 12" apart. The combination of fittings in the assembly from the water line through the solenoid valve and GROmaster valve must result in the GROmaster valve being aligned with the stub up from the drain line. Union shown is optional, but highly recommended and can be placed on either side of the solenoid valve.
The fill/drain rate is as follows