EP2156078A1

EP2156078A1 - Flow stop valve

Info

Publication number: EP2156078A1
Application number: EP08749283A
Authority: EP
Inventors: Oliver Fassmann; Rainer Holzer; Hubert Karner; Wolfgang Ries; Berthold Schulten; Hans Steigenberger; Reinhard Svejkovski
Original assignee: Burgmann Industries GmbH and Co KG
Current assignee: EagleBurgmann Germany GmbH and Co KG
Priority date: 2007-05-15
Filing date: 2008-04-30
Publication date: 2010-02-24
Also published as: WO2008138496A1; DE202007006933U1

Abstract

The invention relates to a flow stop valve for opening and closing a fluid connection between a first and a second space, particularly the blocking fluid chamber of a slip ring sealing arrangement acted upon by a blocking fluid and a space outside of the blocking fluid chamber, having a housing (1), a fluid flow passage (2) in the housing, a first valve seat (11) on the fluid flow passage, and a closing element (6) axially displaceably disposed in the fluid flow passage and pretensioned in a first position in a sealing relationship with the first valve seat by a pretensioning force and moveable against the pretensioning force into a second position, clearing the fluid flow passage. An actuating element (16) that can be engaged with the closing element (6) and can be subjected to the fluid in the first space is designed in order to exercise an axial force on the closing element in the direction of the second position thereof under the influence of a temperature change of the fluid, in order to move the closing element into the second position against the pretensioning force when a specified fluid temperature is exceeded, the closing element being relieved of fluid pressure in the first and second positions.

Description

Flow check valve

The invention relates to a flow control valve for opening and closing a fluid connection between a first and a second space, in particular the barrier fluid chamber of a sealing fluid acted upon mechanical seal assembly and a space outside the barrier fluid chamber, according to the preamble of claim 1.

In double-acting mechanical seal assemblies, a seal fluid chamber is enclosed between a pair of mechanical seals into which a barrier fluid, usually liquid inert to the fluid being sealed, can be introduced. The pressure of the barrier fluid can be adjusted to a suitably higher value than that of the medium to be sealed. The system provides increased safety against leakage to the environment, and further, the barrier fluid may exert a cooling effect on the mechanical seals. Such double acting mechanical seal assemblies are known; it can e.g. Burgmann, Encyclopedia of the mechanical seal, self-published, 1988, p 51, 224 are referenced. There are Sperrfluid idsysteme with and without circulation of the barrier fluid between the barrier fluid chamber and external barrier fluid supply units.

The invention is particularly, but not exclusively, directed to the application to non-circulating barrier fluid systems which require refilling at barrier air. id in the barrier fluid chamber primarily to compensate for losses. In this case, it relates in particular to monitoring the temperature of the barrier fluid in the barrier fluid chamber in order to initiate timely temperature-reducing countermeasures when certain temperature limit values are exceeded.

In view of this objective may be provided between the barrier fluid chamber of a sealing fluid acted upon mechanical seal assembly and a space outside the barrier fluid chamber, a fluid flow check valve having the features of claim 1. This valve is able to open a barrier fluid passage passage when a certain temperature of the barrier fluid is exceeded due to its particular structural design, so that the superheated barrier fluid can flow out of the chamber to the outside and suitable measures can be taken, e.g. by introducing replacement fluid from a foreign source into the chamber so that the temperature in the chamber is returned to a value below the predetermined temperature and thus a cooling effect on the mechanical seals is still guaranteed. When this is achieved, the valve according to the invention automatically closes the passage passage and the normal operating state is resumed in the barrier fluid chamber.

A preferred embodiment of the invention is characterized in that the flow control valve can also exert a venting function on the equipment provided therewith. The means provided for this purpose are listed in subclaim 6, to which reference can be made. Finally, it is preferred that both the closing element and the abutment element represent molded parts made of a PEEK plastic material, which is particularly suitable because of its good mechanical and thermal properties for said components and has the advantage that an undesirable deposition of foreign particles on the moldings, eg metallic Abrasion etc. an effective resistance is opposed. The invention will be explained in more detail with reference to an embodiment and the drawing. Show it:

1 is a perspective longitudinal sectional view of a flow check valve according to an embodiment of the invention,

FIG. 2 is a perspective view of a closing element of the flow blocking valve according to the invention; and FIG

Fig. 3 in an enlarged perspective, partially sectional view of a detail of the flow check valve according to the invention.

With reference to FIG. 1, the flow check valve according to the invention comprises a substantially tubular housing 1 penetrated by a bore 2 providing a passage for a fluid from one axial end to the other axial end of the housing 1. As shown, the bore 2 can be graduated in diameter several times. On a right-hand side in Fig. 1, the housing 1 may be stepped into a tubular neck 3 of reduced outside diameter, on which a screw thread 4 is provided, by which the valve is mounted in a wall, e.g. a barrier fluid chamber (not shown) can be mounted.

At an intermediate region 5 of the housing 1, the bore 2 has an enlarged diameter for receiving a piston-shaped closing element 6, a biasing spring 7 and an abutment element 8. The closing element 6 is shown in Fig. 2 with further details and in particular comprises a sealing region indicated at 9 and one of the biasing spring 7 facing piston guide portion 10th

Although the sealing region 9 could be formed in a different manner, in the present embodiment it comprises an O-ring sealing element which is located in a ner annular groove of the closing element 6 rests and can cooperate with an annular valve seat surface 11 which is provided on a sealing region 9 of the closing element 6 aligned region of the housing bore 2. In the piston guide region 10, a further sealing element 12 may be provided, preferably in the form of an O-ring, which can cooperate with an intermediate, cylindrical guide portion 14 of the housing bore 2 in order to seal the Schliessele- element 6 while axially movable to lead.

As shown in Fig. 2, the closing element 6 is penetrated by a pressure relief bore 15 which extends from one axial end of the closing element 6 to its opposite axial end, so that a fluid present at one end can flow to the other end of the closing element and so the position of the closing element 6 is not affected by the pressure of the fluid. Preferably, the pressure relief hole 15 is formed as a throttle bore to limit the flow of fluid to a suitably low Duchsatzmenge. For a suitable throttle effect, the pressure relief bore 15 may be e.g. have a diameter of 1 to 2 mm.

The biasing spring 7, which is preferably a conical spiral spring, is supported with its one axial end on the closing element 6 and with the other axial end on the abutment element 8. The biasing spring 7 exerts on the closing element 6 and the abutment member 8 from a same biasing force. The biasing force on the closing element 6 causes its sealing region 9 is held with the valve seat surface 11 of the housing bore 2 in a sealing engagement and thereby a passage of fluid along the outer periphery of the closing element 6 is prevented.

The closing element 6 can be moved counter to the biasing force of the biasing spring 7 under the action of an axial force in a position in which the sealing engagement is canceled. To exercise the triggering axial force mounted in the tubular neck portion 3 of the housing 1, an actuating element 16 which is formed so that it undergoes an axial change in length under the action of a change in temperature. In particular, the actuating element may be a so-called expansion material working element, in which an encapsulated expansion substance undergoes an expansion upon a temperature increase, which manifests itself in a movement of a working piston which is in engagement with the facing end surface of the closing element 6. Such expansion work elements are known in the art and need not be described in detail at this point. Suitable expansion elements are, for example, from the company Behr Thermot-tronik GmbH, Enzstrasse 25, D-70806 Kornwestheim to obtain and described in the company's catalog. The actuator 16 is exposed in operation to the fluid in the barrier fluid chamber of a mechanical seal assembly.

The abutment element 8 is piston-shaped in the present embodiment and comprises a biasing spring 7 facing cylindrical portion 17 of increased diameter and a biasing spring 7 facing away from the cylindrical portion 18 of reduced diameter, wherein between the two areas a sealing region 19, preferably in the form of an O Ring sealing element is provided. The sealing portion 19 may sealingly engage a further annular valve seat surface 20 on the inner periphery of the housing bore 2 to provide a sealing relationship between the abutment member 8 and the housing bore 2 under the action of the biasing spring 7.

The abutment member 8 is arranged axially movably in the housing bore 2 and can therefore be brought under an axial force applied thereto opposite the biasing force of the biasing spring 7 in an axial position in which the sealing relationship between the abutment member 8 and the housing bore 2 is repealed and a fluid flow along the outer periphery of the abutment member 8 is made possible. In particular, then a limited fluid exchange between the axial ends of the valve via the pressure relief hole 15 in Closing element 6 and the area between the closing element 6 and the abutment element 8 and take place along this.

The axial force causing a movement of the abutment element 8 is applied by a pin-shaped support member 21 which diametrically passes through the housing bore 2 and abuts the abutment member 8 at one of its axial ends in an elongated, preferably keyhole-like guide groove (not shown) in the peripheral wall the housing bore 2 engages and is held at the other end to a rotatably mounted on the adjacent end portion of the housing 1 coupling ring 23. The guide groove is oriented so that the support element 21 assumes a different axial position with respect to the abutment element 8, depending on the position of its one end in the guide groove. Depending on the rotational position of the coupling ring 23 by hand or by means of a tool, therefore, the support member 21 is fixed in a first position in which no axial force is exerted on the abutment member 8, or in a second position in which the abutment member 8 from the sealing relationship moved out to the housing bore 2.

It should be noted that at the end facing the coupling ring 23 end of the housing 1, a mounting ring 24 attached, for. may be screwed, which may have a hexagonal outer peripheral configuration, so that a rotary tool can be applied thereto to mount the valve in a threaded bore in the wall of a barrier fluid chamber.

Preferably, both the closing element 6 and the abutment element 8 are molded parts made of a suitable plastic material, preferably polyether ether ketone (PEEK) plastic.

The, as mentioned above formed flow check valve works as follows: When the flow check valve in the position shown in FIG. 1 in sealing relationship between the closure member 6 and the housing bore 2 is exposed with its actuator 16 to the fluid in a barrier fluid chamber of a mechanical seal assembly, the aforementioned sealing relationship is maintained until the temperature of the fluid exceeds a certain upper limit and thereby the actuator 16 undergoes such axial expansion that the closing element 6 is moved axially against the force of the biasing spring 7 in the release position. As a result, fluid 6 can flow along the sealing area 9 of the closing element 6 and pass into an annular channel 25 in the housing 1, while it is prevented by the downstream sealing area 10 from continuing along the closing element 6. From the Rinkanal 25, the fluid passes through a connecting bore 26 between the annular channel 25 and the housing bore 2 to the outside. At least a portion of the superheated fluid may therefore be removed from the barrier fluid chamber and replaced with a fluid of suitable temperature.

In this process, the abutment member 8 is in sealing relation to the housing bore 2, so that a fluid exchange along the outer circumference of the abutment member 8 can not take place.

To enable such a fluid exchange, the abutment member 8 can be brought by rotation of the coupling ring 13 in an axial position in which the sealing engagement between the sealing portion 19 and the valve seat surface 20 is repealed and thereby the barrier fluid chamber via the pressure relief hole 15 in the closing element. 6 and the outer circumference of the abutment element 8 is brought into a fluid-exchanging connection with the housing bore 2. This may be used to introduce an exchange fluid into the barrier fluid chamber when the closure member 6 is in the closed position. In particular, a ventilation function for venting the barrier fluid chamber can thus be exercised. If desired, the flow control valve according to the invention can be equipped without such a vent function, in which case the coupling ring 23 and the means for axial movement of the abutment element 8 can be omitted. It is further understood that the sealing effect of the regions 9, 10, 19 can be obtained differently than by O-ring sealing elements, for example by a conical design of the cooperating sealing surfaces. Also, the invention is not limited to the mentioned means for axial movement of the abutment member 8. Finally, the application of the flow control valve according to the invention is not limited to mechanical seal assemblies, but it can thus other equipment in which a similar temperature monitoring function is desired to be equipped.

Claims

claims

A flow check valve for opening and closing a fluid connection between a first and a second space, in particular the barrier fluid chamber of a sealing fluid acted on mechanical seal assembly and a space outside the barrier fluid chamber, with a housing (1), provided in the housing fluid passage passage (2) a first valve seat (11) on the fluid passageway, and a closing member (6) axially movably disposed in the fluid passageway, biased in a first position into a sealing relationship with the first valve seat by a biasing force, and in a second position releasing the fluid passageway the biasing force is movable, characterized by a with the closing element (6) engageable, the fluid in the first space exposable actuator (16) which is adapted to under the action of a change in temperature of the fluid, an axial force on the closing element in the direction de second position to exert the closing element when a certain fluid temperature is exceeded to move against the biasing to the second position, wherein the closing element is fluid pressure relieved in the first and second position.

2. Valve according to claim 1, characterized in that the closing element is designed as a piston element (6) with a pressure relief bore (15) extending from one axial end to the other axial end of the closing element.

3. Valve according to claim 1 or 2, characterized in that the closing element (6) is a molded part made of a PEEK plastic material.

4. Valve according to claim 1, 2 or 3, characterized in that a spring biasing means (7) for biasing the closing element (6) is provided, wherein the spring biasing means having an axial end on the closing element and with ih- the other axial end is axially supported on an abutment element (8) arranged in the fluid passage passage.

5. Valve according to claim 5, characterized in that the abutment element (8) is a molded part made of a PEEK plastic material.

6. Valve according to claim 4 or 5, characterized in that this identifies a vent function by the abutment member (8) arranged axially movable in the fluid passage passage (2) and in the Fluiddurchlasspassge (2), a second valve seat (20) is provided in that the abutment member is biased into sealing engagement in a first position to prevent fluid flow along the abutment member while the abutment member is movable to a second position against the biasing force to provide fluid flow across the pressure relief bore (15) and an area between to allow the closing element and the abutment element from the first to the second space.

7. Valve according to claim 6, characterized in that the housing (2) is formed in two parts, wherein one part is adjustable relative to the other, and on the housing parts cooperating means (21) are provided to move in an adjustment in one of the Housing parts relative to the other exert an axial force on the abutment member in a direction opposite to the biasing force.

8. Valve according to one of the preceding claims, characterized in that the closing element (6) and the abutment element (8) are each carriers of O-ring sealing elements (9,19), which in sealing engagement with the first and second valve seats (11, 20) of the fluid passage passage (2) can be brought.

9. Valve according to claim 6 or 7, characterized in that the pressure relief bore (15) is designed as a throttle bore.