Patent Application
20150059883
This application claims the benefit and priority of European Patent Application No. 13004212.0 filed on Aug. 27, 2013. The entire disclosure of the above application is incorporated herein by reference.
This section provides background information related to the present disclosure which is not necessarily prior art.
1. Technical Field
The invention relates to a pressure-reducing valve for fluid and gaseous media, more particularly for regulating the pressure in pipeline systems, advantageously in buildings, containing a housing, preferably comprising an upper and lower part, an interior housing, wherein the interior housing has a poppet bore, a diaphragm for dividing the housing into a fluid-free and a fluid-flowing area, a pressure adjustment unit, wherein the pressure adjustment unit comprises a spindle, a spring plate, a spring holder and at least one spring, a fastening means and a poppet, wherein the poppet and the diaphragm are connected to one another by means of fastening means, wherein the poppet is arranged in the poppet bore and at least one sealing element is arranged between the poppet and poppet bore for sealing purposes.
2. Discussion
Pressure-reducing valves are used mainly in domestic and industrial water supplies, but they are also to be found in other useful fields and with other media. Also areas which convey ultra-pure media through pipeline systems use pressure-reducing valves, for example in micro-electronics, life-science industries, hospitals and research etc. They serve to reduce the higher pressure in the primary-side distributor network to an optimum pressure for the secondary-side outflow line whereby valve fittings and consumers in the outflow line are protected against pressures which are too high and the service life of the valve fittings can be increased as a result. The noise generated can moreover be reduced by installing a pressure-reducing valve in the outflow line, and the consumption of the medium can also be reduced, more particularly in the case of water supply networks.
DE 44 34 634 C2 discloses a pressure-reducing valve with which the adjustment of the desired output pressure can be easily managed. The medium which is flowing into the housing has a high, or too high, pressure for further use. The desired output pressure can be adjusted by the adjustment unit by suitably pretensioning the spring. This in turn produces the corresponding force on the poppet which regulates the output pressure. If the spring is compressed too strongly then it generates a high counter force on the poppet whereby the desired output pressure is high. The poppet, or its sealing seat which is located between the valve element and the ring-shaped projection of the housing, only closes when the pressure building up in the valve or in the poppet chamber is so great that it exceeds the permissible output pressure, whereby the poppet is pressed against the spring force and the valve element closes the valve seat. The poppet and the valve element with rod consist of several individual parts, furthermore sealing elements are disposed thereon which guarantee the sealing tightness and which are likewise formed as separate parts.
A pressure-reducing valve of this kind is not suitable for use in ultra-pure media since the numerous individual parts increase the risk of contamination. Sealing elements of elastomers, as are conventionally used, are furthermore not permissible for use with ultra-pure media since they cause undesired abrasion which would contaminate the purest medium.
It is an aspect of the invention to propose a pressure-reducing valve which is suitable for use for ultra-pure media and thus cannot cause abrasion of the sealing elements. Places are moreover to be avoided where contamination could easily occur and unnecessary edges and connection sites of individual parts should be reduced to a minimum in the area through which the medium flows. A complete emptying must furthermore be guaranteed so that no residual medium remains at inaccessible places, such as by way of example in blind hole bores or rear-cut sections in the event of complete emptying.
This is achieved according to the preferred embodiment of the invention in that the poppet is designed in one piece and the sealing element is arranged integrally on the poppet or integrally on the interior housing.
The integral arrangement of the sealing element has the advantage that since the sealing element and the poppet or the interior housing are in one piece there are no unnecessary transitions between individual parts which are connected to one another. Cracks and inaccessible surfaces etc. can thereby be avoided and thus the contamination of parts, particularly at inaccessible places, as known in valves of the prior art, can thus be sharply reduced. The seal is produced directly between the poppet or through the integral sealing element on the poppet and the shell surface of the poppet bore of the interior housing or, in the reverse case, between the sealing element disposed integrally on the interior housing, and the outside surface of the poppet. Thus a separate sealing element such as by way of example an O-ring can be omitted, both in the poppet and also in the poppet bore or on the interior housing. The poppet is disposed in the poppet bore as well as the intermediate sealing element for sealing the system. The sealing element can, as previously mentioned, be disposed integrally on the poppet or integrally on the interior housing in the poppet bore.
The poppet is connected to the diaphragm by means of a fastening means. If the output pressure now rises above the value preset by means of the pressure adjustment unit, the medium flowing through the bypass bores disposed in the interior housing presses the diaphragm up against the spring force of the pressure adjustment unit, whereby the poppet is likewise entrained upward in the poppet bore. The integral sealing element of the poppet or the interior housing seals the medium flowing through against the shell surface of the poppet bore or against the outside surface of the poppet preferably above the through-flow openings. As soon as the output pressure is reduced as a result of the closed valve and consequently the pressure decreases underneath the diaphragm, the poppet drops and opens the valve seat which is formed by the sealing edge of the interior housing. The sealing element which is arranged integrally, is preferably formed as a sealing lip. Through the configuration of a sealing lip no great resistance is produced regarding the displacement of the poppet in the poppet bore, which enables the poppet to move easily in the poppet bore without applying any great force whereby a low hysteresis can be effected. This means that in the case of the valve according to the invention the effective output pressure lies close to the preset output pressure, since the sealing element or sealing lip as well as the material from which the poppet is made allow the friction or resistance to be low, which is a great advantage.
Alternatively there is the possibility that the interior housing slides along the poppet. Instead of the poppet the interior housing rises and falls along the stationary poppet, whereby the valve is opened or closed accordingly.
The sealing element or the sealing lip is preferably pressure-assisted. The medium which is flowing through the through-flow openings up to the sealing element or sealing lip acts on the same, which assists the sealing tightness between the poppet and poppet bore of the interior housing.
In order to increase the functional reliability of the valve and to determine and regulate the pressures which occur as far as possible without errors, it is necessary that the poppet in the poppet bore produces the smallest possible sliding resistance. This is achieved in that the poppet is made from a material which has a high sliding capacity or a low friction resistance and thus a low friction coefficient is present between the poppet and poppet bore. The poppet is preferably made from at least one of the materials PTFE, PFA, PVDF and/or TFM, or from a material which has at least one additive of the aforesaid materials. The poppet can be made from one of the materials and also material combinations. Mixtures or compounds are likewise suitable for manufacturing the poppet. Alternatively the poppet can include a further material as reinforcement.
The sealing cone on the poppet serves to restrict the pressure of the medium or to close the valve, as a result of a determined output pressure which lies above the predefined output pressure. When the valve is closed, as a result of the output pressure being too high, the poppet, as a result of the pressure which is acting on the diaphragm, is drawn up high and the sealing cone adjoins the valve seat of the interior housing wherein the valve seat is formed by the sealing edge. The medium is thereby unable to flow through the valve. The sealing cone is preferably arranged integrally on the poppet. However embodiments can also be provided wherein the sealing cone is designed as a separate part and can be fixed on the poppet wherein the useful field of this valve would then possibly be restricted.
The pressure adjustment unit serves for adjusting the output pressure. The spring is tensioned or relaxed corresponding to the desired output pressure and is compressed or pretensioned more or less by means of the spring holder. If the adjustable pressure is not sufficient as a result of one spring, then a second spring can be disposed in the pressure adjustment unit. So that the size of the pressure-reducing valve does not change and the pressure-reducing valve is as compact as possible, the springs are arranged one inside the other. This means that two springs are used which have different spring diameters so that they can be disposed one inside the other. Through the possibility of arranging two springs in the valve the valve gains a larger adjustment range for the output pressure since on the one hand each of the springs can be used individually, and on the other hand both springs can be used together.
An embodiment of the invention will now be described with reference to the drawings wherein the invention is not restricted to only this embodiment. The drawings show:
Example embodiments will now be described more fully with reference to the accompanying drawings.
The poppet 6 is pressed down or opened correspondingly by the springs 11 of the pressure adjustment unit 8. The corresponding spring force which acts through the pretensioned springs 11 by means of the spring holder 22 on the spring plate 10 or fastening means 12 holds the valve 1 opened. The strength of the pretensioning of the springs 11 is obtained by the spindle 9 by means of which the springs 11 can be compressed to a desired length which produces the corresponding pretensioning force or spring force. There is also the possibility of providing only one spring 11 in the valve 1 which reduces the spring force whereby the adjustable output pressure lies in a lower area than when two springs 11 are installed and thereby have a higher spring force and thus permit a higher output pressure. The possibility of arranging the springs 11 in this way makes a wide tension width of the adjustable output pressure possible without changing the structural size of the valve.
| Number | Date | Country | Kind |
|---|---|---|---|
| 13004212.0 | Aug 2013 | EP | regional |
