DE3221416A1 - Pressure-medium-controlled shut-off member for flowing media - Google Patents

Abstract

The invention relates to a pressure-medium-controlled shut-off member for flowing media, with a housing (1) through which the medium flows, a closing part (8) which is guided in the housing (1), can be lifted from a seat and is intended for separating the inflow side from the outflow side, and a drive by means of piston or diaphragm (4) for the closing part (8), having a spindle (7) which is bored through lengthwise and connects the closing part (8) to the piston or the diaphragm (4), and a connection (10), located on the housing (1) and leading in below the piston or the diaphragm (4), for the pressure medium. So that the closing part (8) is also reliably held in the closed position even if the closing force produced on the piston or the diaphragm (4) by the pressure medium or the flowing medium is slight, a spring (16) acting in the closing direction is arranged on the spindle (7) or over the piston or the diaphragm (4). The preloading of this spring (16) is proportioned in such a way that it overcomes the friction of the drive and of the closing part (8) in the respective guides and achieves an adequate seal even if a vacuum virtually develops on the inflow side. <IMAGE>

Description

322U16

Applicant: GAWA Society for Automatic

Water treatment mbH 5014 Kerpen-Türnich

Designation: Pressure medium-controlled closing organ

for flowing media

The invention relates to a pressure medium-controlled closure member for flowing media, with one from Medium-flowing housing, a closure part guided therein, which can be lifted off a seat, for separation the inflow side from the outflow side, a drive by means of a piston or membrane for the closure part with a longitudinally pierced spindle, which connects the closure part with the piston of the membrane, and one located on the housing, below the Piston or the membrane opening connection for the pressure medium.

Closing organs which contain pistons or membranes acted upon by pressure medium are known. Even the use of springs to generate locking or opening forces is known.

Depending on the type of system in which such closure organs are installed, in particular also depending on the safety requirements in the event of a power failure, the pressure of the pressure medium for

^Aa the actuation of the piston or diaphragm drive and the occurrence of non-normal pressure conditions in the system, a corresponding design of the effective areas, the type of pressure medium application and the size and direction of action of the springs

■ "'- made to avoid unwanted or dangerous operating conditions to avoid.

A frequently occurring security-related task is that if the pressure of the pressure medium fails, e.g. due to defects in the pipeline system or at the pressure generating device, or by power

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T fall and the resulting shutdown of the pressure Closing a solenoid valve in the pressure medium line, closing the closing element for the flowing medium must, because otherwise dangerous operating conditions can occur.

There are closing organs for such purposes become known, in which the necessary closing force against the pressure of the flowing medium is generated solely by a suitably dimensioned spring assembly TO will.

Such spring assemblies often consist of three to four individual springs arranged concentrically to one another. Disadvantages of this solution to the problem of generating sufficient closing forces are;
T5 - complex construction,

- Elaborate assembly during production,

- Complicated and dangerous dismantling for repairs, as large amounts of mechanical energy are used during assembly need to be saved,

^ O - Relatively low-lying maximum working pressures of the flowing medium, because the packing density of the springs and thus energy storage capacity is practical Reasons are limited.

There are also embodiments of fluid pressure

controlled closing organs for flowing media become known, in which these difficulties are circumvented in that the top of a piston or Diaphragm drive is acted upon by the pressure of the flowing medium and the opening forces are activated by ■ * " impact of the underside of the piston or the diaphragm can be generated with the pressure of a pressure medium. Although at These valves, the correct way in principle, show all known embodiments the disadvantage that a relatively high minimum pressure of the flowing medium ensures

must be performed so that the required safety function is actually given. This inadequate Working behavior is related to the fact that the collapse that can be generated at low pressures of the flowing medium or membrane forces are too small compared to the frictional forces and that there are insufficient closing forces or surface pressures are generated on the closure part.

Since the cause of the pressure drop in the pressure medium is often also the cause of the pressure drop in the flowing medium (Power failure), is therefore the task according to the invention in the embodiments that have become known only imperfectly realized.

In the embodiment according to the invention, on the other hand, "S is due to the relatively weakly dimensioned closing spring one to overcome the frictional forces and to generate the necessary surface pressure on the closure part sufficient force is generated, as a result of which, for example, the downstream piping system or of

Containers is also avoided if the pressure of the flowing medium on the inflow side is below the static Downstream system pressure drops.

Even if the pressure on the inflow side of the flowing medium is within the physical limits is arbitrarily far below atmospheric pressure, is a flawless embodiment in the case of the embodiment according to the invention Closed position guaranteed when there is atmospheric pressure below the piston or diaphragm, i.e., when no opening pressure is applied by the pressure medium the piston or membrane underside is given.

This functional behavior is in the known embodiments without the spring according to claim 1 not possible because of the negative pressure also prevailing above the piston or the diaphragm, as it did the inflow side of the flowing medium is given, or

the resulting opening force, no closing force is opposed.

An embodiment of the invention is shown in The following description is described in more detail with reference to the drawing:

The closure member has a housing 1 with a diaphragm chamber lower part 2 and a diaphragm chamber upper part 3, the outer edge of the membrane 4 is clamped between the flanges. In the central area the membrane 4 is clamped between the two membrane plates 5 and 6. The diaphragm plates 5 and 6 are connected to the closure part 8 via a spindle 7. The spindle 7 is pierced axially. The hole 17 connects the inflow side in front of the closure part 8 with the space above the membrane 4. At the A sealing ring 9 is arranged on the underside of the closure part 8, which upon closing on the flat annular surface of the seat touches down. Below the membrane 4, the connection 10 for the pressure medium is arranged over either the pressure of an external pressure medium or the pressure of the flowing medium or the atmospheric pressure on the underside of the membrane 4 is given will. The spindle 7 is mounted in a guide sleeve 11, the over the two sealing rings 12 and 13 against the spindle 7 and sealed against the housing 1 via the two sealing rings 14. Trained as a compression spring Spring 16 is seated on the spindle 7 in a sealed manner with respect to the flowing medium and is against it and supported against the guide sleeve 11 so that the force of the spring 16 on the spindle 7 in the closing direction works.

The housing 1 and the guide sleeve 11 can be made of plastic, in particular polyvinyl chloride be. Advantageously, the spring 16 is made of stainless steel, so that even with leaks

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opportunities, for example on the sealing ring 13 and during operation of the closure organ with an aggressive medium ensures the functional reliability of the closure organ remain.

The closing body works as follows:

As a result of the bore 17 prevails below the closure part 8 and above the membrane 4 always the same pressure. Because the area of the membrane 4 is larger is than that of the closure part 8, this pressure generates a resultant force in the closing direction. These The greater the pressure on the inflow side of the flowing medium, the greater the closing force. Below the membrane 4 is atmospheric pressure when the closing element is in the closed operating position is located.

If the closure member is to be opened, the underside of the membrane is exposed to the pressure of a pressure medium applied.

If there is a drop in pressure on the inflow side below the in the closed operating position atmospheric pressure, becomes the required closing force generated by the compression spring 16.

Integration bed fchsn Gefc2d5b washer cios Kt c ;; e an c & r. / ■ ng compared to 31.1 ·? ranz and / or become.

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Claims (4)

322U16 PATENT CLAIMS: (1J pressure medium controlled closing device for flowing Media with a housing through which the medium flows, a closure part (8) guided therein, which can be lifted off a seat, for separating the inlet side from the discharge side and a drive by means of a piston or membrane (4) for the closure part (8) with one of the The length of the pierced spindle (7), which connects the closure part (8) with the piston or the diaphragm (4) connects and one located on the housing (1), opens below the piston or the membrane (4) Connection (10) for the pressure medium, characterized in that that on the spindle (7) or above the piston or the Membrane (4) a spring (16) acting in the closing direction is arranged. 2. Closing member according to claim 1, characterized in that the spring (16) has a bias which to overcome the friction and to create a seal that is sufficient. Surface pressure even with one a partial vacuum on the inflow side of the flowing medium is sufficient, when the underside of the piston is acted upon or the membrane (4) at atmospheric pressure. 3. Closing member according to claim 1 or 2, characterized in that the spring (16) is a compression spring which on the spindle (7), preferably between two sealing rings (12 and 13), is arranged such that it is with does not come into contact with the flowing medium. 4. Closing body according to "one of claims 1 to 3, da- characterized in that the spring (16) is a helical spring is made of stainless steel.