Seal for a joint or juncture – Seal between relatively movable parts – Relatively rotatable radially extending sealing face member
Patent
1992-11-27
1993-08-24
Cuchlinski, Jr., William A.
Seal for a joint or juncture
Seal between relatively movable parts
Relatively rotatable radially extending sealing face member
277115, 277170, 251214, 251330, F16J 1526
Patent
active
052382524
DESCRIPTION:
BRIEF SUMMARY
TECHNICAL FIELD
This invention concerns a shut-off fitting with a sealing device.
BACKGROUND ART
Conventional state of the art uses packing glands as seals for the spindles or arbors of shut-off fittings. As the spindles or arbors turn these seals are subject to high wear, attributable essentially to the dynamic stress of the sealing elements. Other known valve fittings with spindle back seals (conus, labyrinth boxes) are effective only if the valve is opened completely, in which case they constitute an additional static seal. The purpose of this type of seal is in effect to offer the possibility of replacing worn packing glands. Solutions with conventional packing glands do not achieve the sealing quality required under the legal regulations valid in Germany today.
Another known technique is to equip spindle and arbor seals with a bellow-type valve. So far this design has been used only with small nominal diameters (under DN 200). The bellow-type design requires an overall height which is three to four times the diameter of the pipe and thus is unsuitable for many applications, due to a lack of space. In addition, the bellow-type design has the shortcoming that a defective bellow requires the replacement of the entire shut-off fitting.
The shut-off fitting described in the U.S. Pat. No. 2,780,233 also has the disadvantage that it has a relatively large overall height. Neither does the use of a single packing gland, which in this design serves as the main seal in different operating positions, meet the legal requirements that apply in Germany. In particular, compliance with the corresponding sealing requirements cannot be guaranteed during the required replacement of packing glands, because this design lacks a back sealing element. Finally, the design of the solution proposed in U.S. Pat. No. 2,780,233 is relatively complex. This makes it necessary to disassemble and re-assemble a number of parts of the housing when the packing gland is changed.
SUMMARY OF THE INVENTION
Departing from the aforementioned state of the art the purpose of this invention is to create a shut-off fitting, i.e. a sealing device for a shut-off fitting which does not have the disadvantages of conventional solutions and is characterized by a high quality seal. In particular, this fitting is designed to meet the critical requirements of German legal specifications known under the short term "TA-Luft" (TA-Air) dated Feb. 27, 1986. It should allow the manufacture of a particularly tight sealing shut-off fitting with small over height which is suitable for pipes with a large nominal diameter (i.e. over DN 200) at economical cost.
This is achieved by a present invention design of the shut-off fitting which features a sealing area which, due to the greater interior diameter, is not subject to wear as the spindle or arbor is turned. In this design the sealing elements are not subject to pressure until briefly before the closing process of the fitting is completed.
This allows an improvement of the design of the packing gland area, so it safely meets the appropriate legal requirements, i.e. it reliably establishes a seal toward the external environment.
In the course of their use the majority of large scale fittings remains open or shut for extended periods of time because, unlike control valves, they do not often change their operational status. Consequently, for large scale fittings the intervals between actuation are very long, e.g. up to two years. Through an additional static seal in the sealing area for the closed position of the valve as well as for an intermediary position this invention accounts for such modes of operation, which for more than 99% are static. This additional seal is not subject to dynamic stress when the fitting is actuated and consequently experiences practically no wear.
BRIEF DESCRIPTION OF THE FIGURES
The figures show the following:
FIG. 1 shows a valve fitting of this invention in a closed position;
FIG. 2 shows the valve fitting of FIG. 1 in an intermediary position;
FIG. 3 shows the valve fitting FI
REFERENCES:
patent: 317962 (1885-05-01), Ballantine
patent: 1582786 (1925-07-01), Rhodes
patent: 2780233 (1957-02-01), Volpin
patent: 2830787 (1958-04-01), Dale et al.
patent: 2876987 (1959-03-01), Renfro
patent: 3096070 (1963-07-01), Wolfensperger
patent: 3192942 (1965-07-01), Manor et al.
patent: 3379405 (1968-04-01), Natho
patent: 3523551 (1970-08-01), Schmitt
patent: 3537682 (1970-11-01), Priese
patent: 3991974 (1976-11-01), Bonafous
patent: 4289157 (1981-09-01), McGee
patent: 4486002 (1984-12-01), Riess et al.
patent: 4500092 (1985-02-01), Uomala et al.
patent: 4553759 (1985-11-01), Kilmoyer
patent: 4577873 (1986-03-01), Baumann
patent: 4634099 (1987-01-01), Danko et al.
patent: 4640305 (1987-02-01), Johnson
patent: 4745944 (1988-05-01), Francart, Jr.
patent: 4930748 (1990-06-01), Gonsior
patent: 4934657 (1990-06-01), Dodson
Holken Norbert
Stefaniak Klaus
Stewen Wilhelm
Cuchlinski Jr. William A.
Cummings Scott W.
Eisenwerk Heinrich Schilling GmbH & Co.
LandOfFree
Shut-off fittings with a sealing device does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Shut-off fittings with a sealing device, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Shut-off fittings with a sealing device will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-824736