Patent Application
20080301924
When installing packing rings in a stuffing box of a pump, agitator, mixer, valve and the like, a tamping tool is employed to individually tamp or seat each packing ring in the stuffing box.
Many maintenance mechanics do not carry a proper tamping tool; accordingly, the existing packing follower is employed to push the first packing ring as far as it can into the stuffing box but never far enough to push the first ring all the way to the bottom of the stuffing box. Subsequent rings are similarly installed to provide a five or six ring set of packing. The innermost packing rings seal the process medium; therefore, if these rings are not correctly installed, they will not properly compress under the mechanical bolt load provided by the packing follower when the five ring set is installed resulting in the migration of process medium into the bottom of the stuffing box, thereby reducing the life of the packing set and ultimately the equipment itself.
After considerable research and experimentation, the combined tamping tool and packing follower of the present invention has been devised to provide not only a tool to properly seat each ring of a packing set in a stuffing box, but also to function as a packing follower compression loading device to compress the packing set in the installed position in the stuffing box.
The combined tamping tool and packing follower of the present invention comprises, essentially, a sleeve having a threaded outer surface adapted to be threadably mounted in a packing gland. One end of the sleeve is provided with a nose portion adapted to engage each packing ring during the installation of the packing set. The opposite end portion of the sleeve is provided with a plurality of circumferentially spaced apertures adapted to be engaged by a spanner wrench when the tool is being used for properly compressing a packing set. A plurality of circumferentially spaced drain holes extend radially through the sleeve side wall in proximity to the nose portion, and a radially inwardly extending seal is mounted on the interior surface of the sleeve in proximity to the drain holes.
Referring to the drawings, and more particularly to
Heretofore, the conventional packing follower 4 has been employed for installing the packing set 2; however, to provide an adequate fluid tight seal, each sealing ring has to be properly installed in the stuffing box, beginning with the first sealing ring which has to be seated at the innermost end of the stuffing box. Obviously the end portion of the packing follower 4 which extends into the stuffing box 2 is not long enough to push the first sealing ring all the way to the bottom of the stuffing box. If the first sealing ring is not properly installed, then the subsequent sealing rings will also not be properly installed resulting in fluid flowing from the pump 1 along the pump shaft 5 to the bearings 6.
To obviate the problems experienced with conventional packing followers as shown in
The packing gland ring 9, as shown in
The installation of a typical five ring packing set is illustrated in
The sleeve 7 is then pulled out of the stuffing box 2 and a second sealing ring 3b is placed around the shaft, as shown in
The packing gland 9 is then mounted on the equipment through which the sleeve 7 is threaded using a spanner wrench whereby the sleeve 7 is threaded into the stuffing box 5 to thereby put a compression pre-load on sealing rings 3a and 3b.
The installation steps are continued as shown in
From the above description it will be appreciated by those skilled in the art that the combined tamping tool and packing follower of the present invention provides an improvement for installing sealing rings in a stuffing box, in that the device is used not only as a tamping tool for sequentially installing sealing rings in a stuffing box around a shaft, but also once the packing set is positioned in the stuffing box, it is employed as a packing follower for compressing the packing set in the installed position in the stuffing box.
Furthermore, greater packing set life can be expected in that each packing ring has been installed individually with some pre-compression load applied and the double nut and sleeve arrangement transfer the compression load from the pump stuffing box studs to the sleeve 7.
It is to be understood that the form of the invention herewith shown and described is to be taken as a preferred example of the same, and that various changes in the shape, size and arrangement of parts may be resorted to, without departing from, the spirit of the invention or scope of the subjoined claims.
