Fluid handling – With leakage or drip collecting
Reexamination Certificate
1998-10-26
2001-01-30
Shaver, Kevin (Department: 3754)
Fluid handling
With leakage or drip collecting
C137S375000, C285S055000
Reexamination Certificate
active
06178989
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Technical Field of the Invention
The invention concerns a safety function element to influence or control fluid mediums in a line, in particular a double-walled safety line whose walls are spaced at a distance to each other through a hollow space, the element being provided with a housing formed by walls and having as well flanges by means of which it can be connected tightly to the line.
2. Description of the Prior Art
In piping systems in many cases easily inflammable or explosive liquids as well as gases and products that endanger the water and are injurious to health and the environment are transported. Because an uncontrolled release of the transported medium would result in significant damage and risks, for preventive purposes, the use of double-walled safety lines is known, whose walls are spaced at a distance to each other through a hollow space. In this way not only is protection against an escape of the medium directly improved, it is also possible to connect the hollow space to a measuring device to check its contents, for example, a detection device for specific gases or a pressure gauge. Therefore a leak report and subsequent cut-off of transport through the line is effected as soon as the medium enters the hollow space so that the risk of a spillage affecting the environment is completely ruled out.
As a rule, lines are provided with a multitude of function elements. Examples are non-return or shutoff valves, slide valves, pumps or flow meters, which are connected respectively, via flanges, to the line pipes which may comprise rigid or flexible material. In the region of the function elements no suitable measures are known to provide protection against the medium leaking. On the one hand, this has the consequence that operationally the function elements represent a considerable source of danger with leakages occurring with above average frequency compared with the line. On the other hand, during the construction of a line it means significantly higher expenditure because permanent access must be guaranteed, also by statute, even if the line is laid underground, to the function elements. Therefore, in the state-of-the-art, the function element is fitted either in a shaft or an underground loop so that significant extra costs are the disadvantageous consequence. In addition to the function elements themselves, the flanges, to which they are connected, for example, by means of bolts to fit tightly with the adjacent line, represent further regions in which leaks occur especially frequently.
SUMMARY OF THE INVENTION
Against this background, it is the object of the invention to develop a safety function element which offers easily controlled and improved protection against leakage of the medium and therefore does not require direct access.
In accordance with the invention this task is solved therein that the housing is enclosed on all sides by a second wall, which is spaced at a distance to the first wall through a hollow space, which is closed so as to be gastight and connectable to a leak detection device to check its contents and which is connected via one or more bores to a groove which is disposed circumferentially to the line in the sealing surface of the flange or its seal.
The proposed safety function element is enclosed by a housing which has two walls, preferably made from steel, on all sides which are spaced at a distance to each other through a hollow space. The hollow space is closed so as to be gastight and is connectable or permanently connected to a leak detection device to check its contents. It is therefore possible to detect leakage of the medium into the hollow space and to undertake measures, in particular to switch off the line, before a leakage from the hollow space into the environment occurs. In order to also be able to detect a pending leak in the region of the flange, its sealing surface is provided with a groove circumferential to the line, which is, for example, milled. The depth of the groove is to be selected in such a way that the seal of the flange penetrates at most partially therein so that across its entire length a continuous channel is retained. Via one or more bores, or apertures produced in another way, the base of the groove is connected to the hollow space of the housing. If the medium located in the line penetrates into the sealing surface, that is, there is an imminent risk of a leak, it reaches the hollow space via the groove and the bores and can be detected there using the measuring device. In this event, safety measures can then also be taken.
The advantage of the function element according to the invention consists in significantly improved protection against leakage of the transported medium. Although its use is also suitable for a conventional single-wall line, the installation in a double-walled safety line is preferred. Owing to the improved protective effect, it is no longer necessary to have direct access to the element because safety measures can be taken prior to a pending leak and there is sufficient time for repairs. Independent of the type of monitoring, the proposed solution allows the detection of even the smallest leaks. In particular, this creates considerable cost advantages because there is no need to create line loops above ground or access shafts. Furthermore, outside enveloping or insulating layers do not impair the monitoring of the function element.
The function element according to the invention presents itself particularly in the case of shutoff devices, that is, slide valves or valves which comparatively frequently have to be installed in inaccessible regions. Furthermore, the embodiment according to the invention is also advantageous in the case of a non-return valve which likewise is frequently to be disposed inaccessibly. On the other hand, many other function elements, for example, dirt traps, pumps or flow meters, by way of contrast are generally arranged so as to be easily accessible, for instance, in a pumping station, so that direct monitoring is possible.
Function elements frequently have an active part which engages with the fluid medium, for example, the disk of a shutoff valve. Usually a mechanical coupler serves as actuation which acts through a leadthrough in the housing. For example, a valve disk is moved by means of spindle as a coupler so that it is adjustable via a handwheel or a motor that is attached to the housing. To prevent the medium from leaking along the leadthrough, in a development of the invention it is proposed to connect the active part to the housing to fit tightly via a bellows inside of which the coupler engages endwise. In this way, the fluid medium is divided by the leadthrough, while the bellows does not impair the movement of the active part owing to its deformability. Considerably improved protection against leakage of the medium is the advantageous consequence.
With the use of a bellows, it is practical if the volume between it and the housing can be connected to a leak detection device to check its contents so that failure of the bellows can also be detected.
The protection against a leakage of the medium can be further improved if the coupler leadthrough is achieved by means of one or more bushes, so-called safety bushes, which rest against the coupler so as to effect a tight seal. In particular, in the case of a plurality of bushes, in this way a good seal can be achieved even without a bellows.
For filling the hollow space between the housing walls, it presents itself to use a compressed gas, e.g. compressed air, or a vacuum. As a consequence, a leak can be detected simply through a change in the overall pressure so that a plain manometer is sufficient as the leak detection device. Basically, it is advantageous to be able to detect a leak in the interior wall facing the medium as well as in the outer wall facing the environment because in both cases a significantly higher risk of a leakage of the medium exists. This requirement is fulfilled when compressed air or a vacuum is introduced because in both cases the pressure c
Kampfmann Frank
Kolb Hannelore
Windschmitt Hans
Bastianelli John
Schindler Edwin D.
Shaver Kevin
LandOfFree
Safety element for a duct does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Safety element for a duct, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Safety element for a duct will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2552888