assy Valve ver 8 EXPLODED
This is an exploded view of the new valve I built. It is designed to fit into the slots in the concrete in place of the boards. I was able to scrounge lead-screws and handles from an old rusty cast iron valve, as well as the angle iron used for the basic frame. The plastic used for valve parts was either HDPE or Polypropylene obtained from the remnant bin at my local plastic supplier. They sell remnants by the pound, and have a half-price sale once a month, keeping the cost reasonable. I was able to purchase enough plastic to build three valves for just under $100 on sale. The rectangular plastic sheet is about 18 inches square and 5/8 inch thick, with a 12 inch diameter hole through it. This part was flexible enough to bend a bit, so I added two 3/4 X 1/8 thick angle iron stiffeners behind the plate to make it more rigid. Thicker plastic might not require stiffeners, but would cost more, and I had to use what was available in the remnant bin. I would not use less than 1/2 inch thick for this part. The angle irons on the sides and top of the frame are 2 inch X 1/4 inch thick. The two vertical angle iron frame members are about 18 inches long to fit into our 20 inch high concrete structure. The plastic gate has slots in each side that allow it to slide on the vertical members, and the top angle iron member length is set to allow it to slide freely. A tapered plastic spacer is located on each side between the angle iron and the flat plastic plate to position the gate so it touches the flat plate creating a decent seal when closed. A wood 2X4 board is bolted to each side of the flat plastic plate to interface with the concrete structure. Since the slots in the concrete were tapered, the boards were cut to a similar taper. The valve is installed with wood wedges between concrete and 2X4 for a snug fit, and then caulked to help reduce leakage. Caulking was also used between the bottom of the flat plastic plate and the concrete bottom of the structure. There are also two wedges shown in black attached to the moving gate with counter-bored or flathead screws from the sealing side. These wedges match with additional wedge blocks (shown in light grey) mounted to the vertical angle iron sides. The angle on these wedges is about 30-45 degrees. When the valve is closed fully, the wedges mesh pushing the gate tightly against the flat plate for a better seal. The lead-screws I obtained had a right angle bend in the unthreaded bottom end for attaching to the gate. A plastic block was drilled and cross drilled to fit over the lead-screw end. This block is bolted to the gate with flat head screws and is located approximately at the center point of the circular end of the gate. Other arrangements of fastening lead-screws could be implemented, including a threaded block and locking nut to attach the screw while preventing rotation. The method used does allow for a small amount of misalignment caused by the gate moving away from the flat plate when opening and preventing rotation. The wheel used to open and close the valve is attached to the top angle iron with a flange on the bottom of the rotating nut and a block allowing the nut to rotate but not move significantly in the vertical direction. There are several methods of accomplishing this including a threaded wheel with a flange on the bottom, or the hex shaped wheel shown in the CAD model where the wheel can be removed if desired. A threaded nut is installed on the lead-screw above this nut and below the nut to set the maximum and minimum distance the valve can be opened. These nuts are located with set screws once final adjustment is determined. The top nut can also be used to prevent removal or theft of the wheel if a HEX design is used, and could be welded in place for maximum security at the expense of further adjustment. Not shown are bolts for attaching all the parts and for holding the angle iron frames together. I suggest not welding the top angle to the side angles to allow dismantling the valve easily if repairs are ever required. Most repairs can be accomplished without disturbing the caulking or removing the 2X4's from the concrete structure.
