IMPROVED MINIMUM PRESSURE VALVE AND METHOD FOR SERVICING SUCH A VALVE

Abstract

The invention relates to a minimum pressure valve (10) comprising a housing (17) with the valve inlet (11) and the valve outlet (12) connected with each other by means of a chamber and connecting space (22a, 22b), the minimum pressure valve (10) also comprising a valve body (21) set up in a chamber (20) moveably between a closed position in which the valve inlet (11) is closed and an open position in which the valve inlet (11) is open, the minimum pressure valve (10) also comprising components which are provided with a seal and/or sliding parts (24, 26, 30), whereby a subassembly (22) of the minimum pressure valve (10) can be disassembled and/or assembled through an opening (31) in the housing (17).

Claims

1-21. (canceled)

22. A minimum pressure valve (10) comprising a housing (17) with a valve inlet (11) and a valve outlet (12) connected with each other by means of a chamber and connecting space (22a, 22b), whereby the minimum pressure valve (10) also comprises a valve body (21) that is set up in a chamber (20), moveably between, on the one hand, a closed position in which the valve inlet (11) is closed off and, on the other hand, an open position in which the valve inlet (11) is open, whereby the minimum pressure valve (10) also comprises components which are provided with a seal and/or sliding parts (24, 26, 30), characterised in that a subassembly (22) of the minimum pressure valve (10) can be disassembled and/or assembled through an opening (31) in the housing (17), and that the subassembly (22) has a specific shape so that it can only fit in the housing (17) of the minimum pressure valve (10) in one particular way.

23. A minimum pressure valve (10) according to claim 22, characterised in that the opening (31) is located in the side wall of the housing (17) of the minimum pressure valve (10).

24. A minimum pressure valve (10) according to claim 22, characterised in that said subassembly (22) comprises the components which are provided with a seal and/or sliding parts (24, 26, 30), such as sealing rings and/or slide rings, said components comprising the chamber (20), the valve body (21) and the non-return valve (36).

25. A minimum pressure valve (10) according to claim 22, characterised in that the opening (31) in the housing (17) of the minimum pressure valve (10) is covered by a lid (32).

26. A minimum pressure valve (10) according to claim 25, characterised in that said lid (32) is mounted on the housing (17) with bolts (34) or another type of fastener that can be detached and then reattached.

27. A minimum pressure valve (10) according to claim 25, characterised in that a seal (38) is provided between the lid (32) and the housing (17) of the minimum pressure valve (10) in order to guarantee air tightness.

28. A minimum pressure valve (10) according to claim 22, characterised in that the subassembly (22) with the components which are provided with a seal and/or sliding parts (24, 26, 30) can pass through the opening (31) in the side wall of the housing (17) of the minimum pressure valve (10).

29. A minimum pressure valve (10) according to claim 22, characterised in that the subassembly (22) with the components which are provided with a seal and/or sliding parts (24, 26, 30) can be fixed inside the minimum pressure valve (10), for example using clamps or another type of fastener that can be detached and reattached.

30. A minimum pressure valve (10) according to claim 22, characterised in that the lid (32) and the subassembly (22) with the components which are provided with a seal and/or sliding parts (24,26, 30) are connected, so that said subassembly (22) can be removed together with the lid (32).

31. A minimum pressure valve (10) according to claim 22, characterised in that said subassembly (22) and/or the lid (32) are equipped with extra functions, such as a handle (33) on the lid (32), in order to facilitate handling.

32. A minimum pressure valve (10) according to claim 22, characterised in that the subassembly (22) is provided with a connection (40) so that a particular air pressure can be applied to the components.

33. A minimum pressure valve (10) according to claim 32, characterised in that said connection (40) is connected to a connection in the housing (17) of the minimum pressure valve (10).

34. A minimum pressure valve (10) according to claim 33, characterised in that said connection (40) is realised by clamping the subassembly (22) with the components which are provided with a seal and/or sliding parts (24, 26, 30) against the housing (17), whereby an outlet in the housing is connected with an inlet of the subassembly (22), whereby the connection preferably also has a seal suitable for a particular tolerance and for guaranteeing air tightness.

35. A minimum pressure valve (10) according to claim 32, characterised in that said connection (40) is connected to a connection in the housing (17) of the minimum pressure valve (10) using a flexible pipe and screw or bayonet catch.

36. A minimum pressure valve (10) according to claim 33, characterised in that said connection (40) is integrated in the lid (32), and this lid (32) is connected with the subassembly (22) with the components which are provided with a seal and/or sliding parts (24, 26, 30), so that after assembly of the subassembly (22) provided with the lid (32), an external flexible pipe can be connected to the lid (32) in order to provide air pressure to the subassembly (22) with the components which are provided with a seal and/or sliding parts (24, 26, 30).

37. A compressor (1) comprising a compressor element (2) with a gas inlet (3) and an outlet (4) for compressed gas, the compressor (1) also comprising a pressure vessel (6) with an inlet (7) connected to the outlet (4) for compressed gas, whereby a minimum pressure valve (10) according to claim 22 is provided on an outlet (8) of the pressure vessel (6), the minimum pressure valve (10) being connected with the valve inlet (11) to the outlet (8) of the pressure vessel (6) and the valve outlet (12) being adapted to be connected to a user network (9), whereby the minimum pressure valve (10) comprises a housing (17) whereby the valve inlet (11) and the valve outlet (12) are connected by means of a chamber and connecting space (22a & 22b), the minimum pressure valve (10) also comprises a valve body (21) set up in a chamber (20) moveably between a closed position in which the valve inlet (11) is closed and an open position in which the valve inlet (11) is open, whereby a subassembly (22) of the minimum pressure valve (10) can be disassembled and/or assembled through an opening (31) in the housing (17), preferably in the side wall of the housing (17).

38. The compressor (1) according to claim 37, characterised in that the compressor is a liquid or oil-injected compressor.

39. A compressor (1) according to claim 37, characterised in that the compressor (1) comprises the minimum pressure valve (10).

40. A method for servicing a minimum pressure valve (6) of a compressor (1), the compressor (1) comprising a compressor element (2) with a gas inlet (3) and an outlet (4) for a compressed gas, the compressor (1) also comprising a pressure vessel (6) with an inlet (7) connected to the outlet (4) for compressed gas, whereby a minimum pressure valve (10) according to claim 22 is provided on an outlet (8) of the pressure vessel (6), the minimum pressure valve (10) is connected with the valve inlet (11) to the outlet (8) of the pressure vessel (6) and the valve outlet (12) is adapted to be connected to a user network (9), whereby the minimum pressure valve (10) comprises a housing (17) whereby the valve inlet (11) and the valve outlet (12) are connected by means of a chamber and connecting space (22a, 22b), the minimum pressure valve (10) also comprising a valve body (21) set up in a chamber (20) moveably between a closed position in which the valve inlet (11) is closed and an open position in which the valve inlet (11) is open, characterised in that a subassembly (22) of the minimum pressure valve (10) can be disassembled and/or assembled through an opening (31) in the housing (16), preferably in the side wall of the housing, said subassembly (22) comprising the components which are provided with a seal and/or sliding parts (24, 26, 30), such as sealing rings and/or slide rings.

41. The method according to claim 40, containing the following steps: detaching the bolts (34) of the subassembly (22), removing the subassembly (22) from the opening (31) in the minimum pressure valve (10), removing the valve body (21), replacing the seal (24) and slide rings (35), removing the non-return valve (36) and replacing the slide rings (37), reassembling the non-return valve (36) and the valve body (21), tightening the bolts (34) of the subassembly (22) on the housing (17) of the minimum pressure valve (10).

Description

[0050] With the intention of better showing the characteristics of the invention, a preferred embodiment of a minimum pressure valve according to the invention is described hereinafter, by way of an example without any limiting nature, with reference to the accompanying drawings, wherein:

[0051] FIG. 1 schematically shows a compressor according to the invention;

[0052] FIGS. 2 and 3 schematically show a cross-section of a minimum pressure valve of an embodiment according to the invention;

[0053] FIGS. 4 and 5 schematically illustrate a seal that can be used with the minimum pressure valve according to the invention; and

[0054] FIGS. 6 and 7 schematically show a view and cross-section of a minimum pressure valve according to a preferred embodiment of the invention.

[0055] FIG. 1 illustrates a compressor 1 consisting of a compressor element 2 with a gas inlet 3 and a compressed gas outlet 4. The compressor 1 is usually driven by a fixed or variable-speed motor 5.

[0056] The compressor element 2 must be interpreted as the housing in which the compressor process takes place by means of a rotor or via a piston compressor movement.

[0057] The compressor 1 comprises a pressure vessel 6 with an inlet 7 connected to the compressed gas outlet 4 and an outlet 8 connected to a user network 9. This pressure vessel 6 is also known as a liquid separator, because it is inside this vessel that the air is separated from most of the liquid. The separated liquid is then returned to the compressor element via the return pipe 16.

[0058] The compressor 1 also comprises a (coalescence) filter which is either mounted in the liquid separator 6, or in a separate pressure vessel 13 after the liquid separator 6.

[0059] A minimum pressure valve 10 is provided at the outlet 8, on the liquid pipe provided between the pressure vessel 6 and the user network 9.

[0060] The minimum pressure valve 10 has a valve inlet 11 connected to the outlet 8 of the pressure vessel 6 and a valve outlet 12 adapted to be connected to a user network 9.

[0061] A pipe 14 connects the outlet 8 of the pressure vessel 6 with the pressure control entry of the minimum pressure valve 10; in this pipe a control unit 15 is provided which regulates the pressure supply via the supply pipe 14.

[0062] FIGS. 2 and 3 show a cross-section of a minimum pressure valve 10 according to the invention.

[0063] The minimum pressure valve 10 comprises a housing 17 with a housing inlet 18, a housing outlet 19, a chamber 22a for receiving a removable subassembly 22 and a connecting space 22b between the chamber 22a and the housing outlet 19.

[0064] The housing inlet 18 is brought in fluid connection with the valve inlet 11 and the housing outlet 19 is brought in fluid connection with the valve outlet 12 when the minimum pressure valve is mounted within the compressor 1.

[0065] The minimum pressure valve 10 comprises a valve body 21 that is moveable in a chamber 20 between a closed position in which the valve inlet 11 is closed and an open position in which the valve inlet 11 is opened.

[0066] When the valve inlet 11 is closed, no or practically no liquid is allowed to flow through the minimum pressure valve 10, thus from the housing inlet 18 to the housing outlet 19 and further towards the user network 9.

[0067] Considering that, when the valve inlet 11 is open, liquid is allowed to flow through the minimum pressure valve 10, from the housing inlet 18 to the housing outlet 19 and further reaching the user network 9.

[0068] The pressure which determines whether the valve body 21 moves to an open position, is determined by a control unit 15.

[0069] In commonly used minimum pressure valves 10, a spring is used to set the pressure value whereby the minimum pressure valve is opened and such a spring is selected to suit the capacity and the pressure range of the compressor 1.

[0070] In the embodiment of the figures a control unit 15 replaces said spring, hereby avoiding the need for components which would be difficult to fit or replace as described in BE 2018/5011.

[0071] The control unit 15 comprises a pipe 14 which forms a connection between the outlet 8 of the pressure vessel 6 and a space contained between the valve body 21 and the chamber 20.

[0072] The channel 40 will be used to transport air to a first end 21a of the valve body 21.

[0073] The chamber 20 comprises a groove 27 or recess above a first end 21a of the valve body 21.

[0074] Such a groove 27 creates a hollow space between the inside of the chamber 20 and the valve body 21 at the level of the first end 21a.

[0075] In the context of the present invention it should be understood that minimum pressure valves containing on the one hand a spring or on the other a control unit 15, are within the scope of the invention.

[0076] The valve body 21 comprises a seal 24 that is adapted to be mounted on the outer contour 24a of the valve body 21, thus between the valve body 21 and the internal side of the chamber 20.

[0077] The seal 24 is mounted between the first end 21a and the second end 21b of the valve body 21.

[0078] Such a seal 24 is therefore positioned so that there is a separation between on the one hand the space contained between the seal 24, the groove 27 and the first end 21a, whereby the pressure value is defined by the pressure of the liquid flowing through the channel 40, and on the other hand the space contained between the seal 24, the second end 21b and the connecting space in the housing 17 between the housing inlet 18 and the housing outlet 19, whereby the pressure value is defined by the pressure supplied to the housing inlet 18 in the case that the valve body is in the open position or by the relevant pressure in the valve outlet 19 in the case that the valve body is in the closed position.

[0079] Depending on the requirements for the minimum pressure valve 10, more than one seal 24 may be fitted, such as for example 2, 3 or more seals.

[0080] Preferably, a bi-directional seal is used. Such a seal will work in both directions. FIGS. 4 and 5 show a cross-section of such a seal.

[0081] Alternatively, two single-action seals can be used, placed back-to-back or front-to-front in series.

[0082] Although the figures show the seal placed around the valve body 21, it is also possible to place this in the housing 17 of the minimum pressure valve 10 by providing a groove in the chamber 20.

[0083] Preferably, but without limiting nature, these seals can be characterised by very low friction and little stick-slip.

[0084] The valve body 21 comprises a conductive element 26, adapted to be fitted on the outer contour 26a of the valve body 21, between the valve body 21 and the inside of the chamber 20.

[0085] Such a conductive element 26 reduces the wear on the valve body 21 and on the inside of the chamber 20. This wear is caused by the movement of the valve body 21 within the chamber 20 and the friction caused upon this.

[0086] One or more conductive elements can be provided. In addition the conductive elements 26 absorb the transverse forces that occur during the movement of the valve body 21 within the chamber 20. Consequently, these conductive elements 26 prevent the valve body 21 from tipping within the chamber 20 and subsequently becoming stuck in the chamber 20.

[0087] The seal 24 is fitted between two conductive elements 26. The conductive element 26 can be executed in the form of a seal, a slide ring or a conductive tape.

[0088] Although in the figures the conductive element 26 is placed around the valve body 21, it would also be possible to place this in the housing 17 of the minimum pressure valve 10 by providing a groove in the chamber 20.

[0089] The valve body 21 comprises a bore 28 in which the piston 23 of the non-return valve 36 is mounted. This non-return valve is moveable between a closed position in which the housing inlet 18 is closed and an open position in which the housing inlet 18 is opened.

[0090] In the piston 23 a channel 25 is provided to ensure that no air mounts up between the end of the piston 23 and the end of the internal bore 28 in the valve body 21 in which the piston 23 moves.

[0091] For a stable and balanced operation of the non-return valve the axis of the bore 28 is aligned or almost aligned with the axis of the valve body 21.

[0092] The step section 29 of the non-return valve 36 ensures a seal between the outlet 12 of the minimum pressure valve 10 and the outlet of the pressure vessel 6.

[0093] For a flowing movement between the piston 23 and the valve body 21 and for the protection of the piston 23 and the valve body 21 from the harmful effects of the friction that is caused upon it, the piston 23 also comprises a second conductive element 30 which is adapted so that this can be mounted in position 30a between the piston 23 and the valve body 21.

[0094] Although in the figures the second conductive element 30 is placed around the piston 23, it would also be possible to place this in the valve body 21 of the minimum pressure valve 10 by providing a groove in the central bore 28 of the valve body 21.

[0095] Depending on the design the minimal pressure valve 10 can consist of some or even all technical characteristics and functions mentioned herein and in any desired combination thereof. Technical characteristics and functions refers here to: all components of the compressor 1 and the control unit 15 (can also be replaced with a spring), the pipe 14, the valve body 21, the channel 25, the piston 23, the seal 24, the conductive unit 26, the groove 27, the step section 29 and the second conductive unit 30. These functions do not all need to be present.

[0096] As indicated in the FIGS. 2, 3, 6 and 7, part of the minimum pressure valve 10 is removable (the subassembly 22) through an opening 31 in the housing 17; we call this removable part the subassembly. Subassembly refers here to: the lid 32, the valve body 21, the seal 24, the conductive unit 26, the piston 23, the step section 29 and the second conductive unit 30. These components do not all need to be present.

[0097] The subassembly has an integrated cover plate or lid 32 which covers the opening 31 in the housing 17 of the minimum pressure valve 10, preferably in the side wall of the housing 17. An optional handle 33 used to easily remove the subassembly is fixed to the outside of the lid 32.

[0098] The subassembly is attached to the outside of the housing 17 of the minimum pressure valve 10 with the help of four bolts 34.

[0099] In addition, the subassembly, which can be taken out of the minimum pressure valve 10, is provided with a connection 40 so that a particular air pressure can be applied to the components.

[0100] Servicing of the minimum pressure valve 10, according to the invention, is carried out as follows:

[0101] First the four bolts 34 on the subassembly and the connection of the pressure supply pipe coming from the control unit 15 on the connection 40 in the housing 17 are detached. Next the subassembly is taken out of the housing 17 using the handle 33. Then the valve body 21 is taken out of the chamber 20.

[0102] The seal 24 and the two slide rings 26 are now easily accessed for replacement.

[0103] The non-return valve 36 (including the piston 23) is taken out of the valve body 21 whereby the two slide rings 30 can be replaced.

[0104] The piston 23 and the non-return valve 36 are mounted in the valve body 21 using self-alignment; the same occurs with the valve body 21 in the chamber 20.

[0105] Finally the four bolts 34 on the subassembly are tightened on the housing 17 of the minimum pressure valve 10, and the pressure supply pipe coming from the control unit 15 is reattached to the connection 40 in the housing 17.

[0106] In the example shown a seal 38 is provided between the lid 32 and the housing 17 of the minimum pressure valve 10 in order to guarantee air tightness. This seal 38 will also be easily accessed for replacement when the subassembly is removed from the housing 17 using the handle 33.

[0107] The present invention is by no means limited to the embodiment described as an example and shown in the drawings, but a minimum pressure valve, compressor and method according to the invention as defined by the claims, can be realised in all kinds of variants without departing from the scope of the invention.