| 摘要 |
<p>A subterranean well casing float tool is comprised of a tubular metal housing which is securable to a well casing conduit. Varing means are implaced within the housing, with substantially all of the components of the valving means, save a biasing means, are thermosetting. The valving means has a thermosetting frame and valve head and valve seat means relative to the frame. A biasing member, such as a compressed spring is used for urging the valve head toward the valve seat to a closed position. A compartment including the valve head is provided for enclosure around the biasing means when the valve head is moved fully away from the valve seat to protect the spring from errosive turbulent fluid flow when the valve head is in the open position relative to the seat. The valving means is directly secured to the housing by means of thread members having profiled shear surfaces such that the shear area of the valving means is substantially greater than that of the metal housing.</p> |
