A CONDUIT-BREAK VALVE FOR A PRESSURE CONDUIT OR HOSE WITH A SURROUNDING PROTECTIVE CONDUIT OR HOSE

Abstract: A conduit-break valve for a double hose or conduit is designed to operate under a higher pressure between the hoses or conduits than that prevailing in the inner hose or conduit and than that of the ambient atmosphere. The valve has a valve member (16) which is urged by a spring (24) towards its valve seat (15). A diaphragm or piston device (18) normally maitains the valve member (16) in open position by the action of the pressure in a pressure chamber (22) which is connected to the space between the hoses. At a break of the inner and/or the outer one of the hoses or conduits the pressure in the pressure chamber (22) is reduced and the valve is closed by the action of the spring (24).

Description: A CONDUIT-BREAK VALVE FOR A PRESSURE CONDUIT OR HOSE WITH A SURROUNDING PROTECTIVE CONDUIT OR HOSE In many situations one has need of being able to shut off a pressure conduit or hose at conduit breaks. This may be the case for instance with regard to gas conduits or pressure oil conduits. One has therefore developed various types of conduit-break valves. As examples of some such valves mention may be made of the published European patent application 79850114.4 (Publ. No. EP-A1-0 013 264) and the two published West German patent applications DE-A1-28 23 262 and 29 28 529. Common to all of these valve mechanisms is that they com¬ prise a valve member which is movable in a valve housing between an open position and a closed position prevent¬ ing throughflow through the valve and which is yielding¬ ly urged towards its closed position and adapted to be actuated in response to a pressure medium in the space between the two conduits or hoses. In EP-A1-0 013 264 a break of the inner hose results in an increase of the pressure in the space between the two hoses such that a release mechanism rapidly relieves the pressure between the two hoses, whereby a valve spring closes the valve member. In the mechanisms according to DE-A1-28 23 262 and DE-Al-29 28 529 a break of the inner hose will result in an increase of the pressure in the space between the two hoses such that this increased pressure moves a piston device connected to the valve member to closed position. This device is dependent on a differential pressure being allowed to act against differently large surfaces of reaction. A damage to the outer hose does not however lead to a closure of the valve mechanism. The same is true of the mechanism according to DE-Al-29 23 262. This invention has for its object to provide a conduit-break valve which can be employed not only for transporting media under high pressure but also such • media as gases under a relatively low pressure but will .still ensure shut-off of the main conduit upon a break of the pressure conduit or hose or of the protective conduit or hose or of both the pressure conduit and the protective conduit or hose. The invention thus relates to a conduit-break valve of the type defined in the introduction, and the valve is characterised in. that it ^ is adapted to operate under a higher pressure in the space between the two conduits or hoses than that prevailing in the pressure conduit or hose and than that of the ambient- atmosphere, and that the valve member is connected to a piston or dia¬ phragm device, the piston or diaphragm of which defines a pressure chamber communicating with the space between- the two conduits or hoses and is adapted normally to maintain the valve member in its. open position. A conduit-break valve designed in this way possesses the desired properties. In certain cases, an insigni- ficant .leakage of the pressure conduit or hose or of the protective conduit or hose may however result in too slow a closing procedure- or course. In a further development of the invention, the conduit-oreak valv^- *- "" therefore comprises a sensing and pressure relief echa- . nism which is adapted to sense the position of the main valve member and, upon displacement of the main valve member from its open position towards .its closed posi¬ tion, to relieve the pressure in the pressure chamber such that the valve member is rapidly closed by the action of the yieldable loading of the valve member. The yieldable loading can be attained .with, the aid. of a pressure spring which acts against the piston or dia¬ phragm device. According to the invention, it is particularly advantageous if the sensing and pressure relief mecha¬ nism is formed as a mechanical relief valve having a valve member which is urged towards its closed position P and has a valve rod adapted to be actuated by the valve member of the conduit-break valve and to unseat the valve member of the relief valve, thus opening the re¬ lief valve for relief of the pressure in the pressure chamber. The invention will be described more in detail in the following, reference being had to the accompanyin drawings which illustrate three embodiments of the valve according to the invention. In the drawings: Figs. 1 and 2 show an embodiment of the conduit- break valve in two different positions; Figs. 3 and 4 illustrate in the same manner another embodiment of the conduit-break valve according to the invention; and Figs. 5 and 6 illustrate a third embodiment of the conduit-break valve in two setting positions. The conduit-break valve shown in Figs. 1 and 2 is adapted for connection with a double conduit com¬ prising an inner pressure conduit or hose 10 and an outer protective conduit or hose 11. In the embodiment illustrated these components are hoses with connecting nipples for connection to a valve housing 12. The valve housing 12 has an outlet 13 and an inlet 14 and an inner valve seat 15. The connecting nipple of the pressure hose 10 projects into the inlet 14 and seals against the wall thereof. In the valve housing there is provided a valve body or member 16 which is supported by a valve rod 17. The rod 17 in turn is attached to a diaphragm holder 18 which protrudes with a guide pin 19 through a spring housing 20. The spring housing 20 is mounted on the valve housing 12 and clamps a diaphragm 21 along the edges of said diaphragm in order thereby to define a pressure chamber 22 in the valve housing. At the bot¬ tom of the pressure chamber 22 there is a guiding and sealing device 23 through which the valve rod 17 extends. A pressure spring 24 is interposed between the spring housing 20 and the diaphragm holder 18 and thus urges the valve member 16 towards closed position (Fig. 2) . In the valve housing 12 there is also provided a passage 25 which connects the pressure chamber 22 to the space 26 between the two hoses 10, 11. The conduit-break valve according to Figs. 1 and 2 operates as follows: When the conduit-break valve is to be put in operation, one increases the pressure in the space 26 between the two hoses 10, 11 to so high a pressure above atmospheric that the diaphragm is moved upwards to the position shown in Fig. 1, the pressure spring 24 being compressed. The pressure in the space 26 and the pressure chamber 22 shall thus be higher than both the ambient pressure and the pressure prevailing in the pressure hose 10. A break of the pressure hose or inner hose 10 results in that the pressure prevailing in the space 26 and the pressure chamber 22 is relieved into the pressure hose 10. In a similar manner a relief of the pressure prevailing in the space 26 is obtained to the ambient atmopshere, if a break should occur on the conduit 11. Upon relief of the pressure prevailing in the space 26 and the pressure chamber 22 the pressure spring 24 will successively move the valve member 16 downwards until the valve member. seals against its seat 15 and thus shuts off the valve and thus the transport of medium through the valve. The embodiment according to Figs. 1 and 2 can be employed for different types of media, such as liquids and gases. It is particularly suited for gases. The valve according to Figs. 1 and 2 is so designed that a small hole in the inner or outer hoses or inner or outer conduits 10, 11 will result in a slow pressure reduction in the pressure chamber 22 and, consequently, in a slow shut-off procedure. The embodiment accord¬ ing to Figs. 3 and 4 gives a more rapid shut-off pro¬ cedure. In Figs. 3 and 4 the same reference numerals have been employed as in Figs. 1 and 2 to facilitate a comparison. The embodiment according to Figs. 3 and 4 differs from that according to Figs. 1 and 2 mainly by the de- sign of the spring housing 20 and the components mounted thereon.. The device according to Figs. 3 and 4 thus has a passage 27 which is connected to the passage 25 of the valve housing and leads to a. pressure gauge 28 and to further passages 29, 30 in the spring housing 20. The diaphragm holder 18 in. this embodiment is de¬ signed as a valve cone or member 31 with an O-seal 32 inserted in the sealing surface to .seal against a valve seat 33 surrounding the passage 30. The space 34 in which the spring 24 is arranged, is in communication with, the ambient atmosphere through a vent hole 35. The device further comprises a shut-off valve 36 with a valve member 37 sealing against the edge of the mouth of the passage 29. The spring housing .20 besides has a filling nipple 38 which is connected to the passages 27 and 29. The function of the device according to Figs, 3 and 4 is as follows. When the device is to be put in operation the valve 36 is closed and the pressure in the space 26 between the hoses 10, 11 and in the passages 25, 27, 29 and the pressure chamber 22 is raised by pressure fluid being supplied through the filling nipple 38 which may be designed as a.check valve. At this rise of pressure in int.al. the pressure chamber 22 the spring-24 will be compressed to such an extent that the valve 31, 32, 33 is closed. The expulsion of the air in the chamber 34 takes place through the vent hole 35. After that, the valve 36 is opened to the position shown in the Figures. If the conduit-break * valve according to this embodi¬ ment is employed for example for propane gas one usually has a pressure of say 0.03 Bar in the inner hose 10, and with this pressure it may be sufficient to use a pressure of ' 0.15 Bar in the space 26 between the hoses. As long as the hoses 10, 11 are intact the conduit-break valve remains in the state shown in Fig. 3. Should a break occur on the inner or the .outer hose or on both OMP hoses 10, 11 the pressure will sink in the chamber 22 so that the diaphragm holder 18 begins to move to the left as seen in Fig. 3. As soon as this movement is initiated, the valve formed by the components 31-33 will be opened so that a free passage from the space 26 to the ambient atmosphere is immediately attained via the passages 25, 27, 29, 30, the chamber 34 and the vent hole 35. This leads to an instantaneous closure of the valve 15, 16 by the action of the pressure spring 24. The pressure gauge 28 in the embodiment according to Figs. 3 and 4 can be used to watch that the excess pressure in the space 26 between the two hoses 10, 11 lies within the .suitable range. Too low a pressure, say in the vicinity of 0.10 Bar, leads to a great risk of unintentional quick release of the valve, and too high a pressure may be unsuitable with regard to the conduit and hose equipment. The quick release valve 31-33 in the embodiment according to Figs. 3 and 4 operates although the same pressure prevails in the chamber .22 as that in the pas¬ sage 30. The pressure force taken up by the large area of the diaphragm thus is greater than the total pressure force of the spring 24 and the pressure acting upon the small free area opposite the passage 30. As shown in Figs. 5 and 6, the conduit-break valve according to the invention can be provided with a piston device instead of a diaphragm device. This embodiment of the invention is particularly suited for say oil conduits where one operates with higher pressures or for media which might damage the diaphragm in the two embodiments described in the foregoing. The conduit-break valve shown in Figs. 5 and 6 has a valve housing 40 with an inlet 41, an outlet 42 and a connecting passage 43. In the valve housing there is provided a valve seat 44 for a valve cone or member 45. The valve cone 45 has a valve rod * 46 which is guided in a guiding and sealing device 47. Said guiding and sealing device 47 forms one end wall of. a pressure cham¬ ber 48, the other end wall of which is formed by a pis¬ ton 49 which is fixedly mounted on the valve rod 46 and suitably, sealed against the wall of the pressure chamber 48. The piston 49 is under the action of a pres¬ sure spring 50 in a spring housing 51. From the pressure chamber 48 leads a passage 52 which is connected in a suitable manner to a space 53 between an inner pressure conduit 54 and an outer pro¬ tective conduit 55. These conduits are mounted in a suitable way on the valve housing 40, the nipple 56 of the pressure conduit 54 sealing against the wall of the outlet 42 of the valve housing 40. Same as in the embodiment according to Figs. 3 and 4 there is provided a sensing and pressure relief mechanism which is " intended rapidly to relieve the pres¬ sure in the pressure chamber 48, should a break occur on the inner or outer conduit 54, 55..In this case use is made of a mechanical relief valve which has a valve rod 57 and valve ball or member 58 which is normally urged by a pressure spring 59 into sealing engagement with a seat 60. When the valve ball 58 is in engagement with the seat ' 60 the connection between the pressure chamber 48 and a collecting chamber 61 is broken. This connection is established via the passage 52 and a pas¬ sage 62 in the valve housing 40 as well as a passage 63 in a- valve . housing 64 in which the quick release valve is provided. In said valve housing 64 there are also provided passages 65 and 66 which lead to the col¬ lecting chamber 61. In the transition between the chan¬ nel 65 and 66 there is disposed a shut-off valve 67, in the form of a needle valve, which acts against the mouth of the passage 65. in the valve mechanism according to Figs. 5 and 6 the pressure in the space 53 * between the hoses 54 and 55 is raised with the aid of..a filling device 68 at the other end of the conduits or hoses 54, 55. OMP > wiF ... The mechanism shown in Figs. 5 and 6 operates in • the following manner. When the mechanism is to be put in operation the needle valve 67 is screwed into engagement with the mouth of the passage 65. Then the pressure in the system is raised by a pressure medium being supplied through the valve mechanism 68. As a result, the piston 49 will be moved upwards to" the ' position shown .in Fig. 5, the spring 50 being compressed. At the same time the valve ball 58 and the valve rod 57 will be moved upwards to the position shown in Fig. 5 as the valve member 45 moves upwards together with the piston 49. After the prescribed excess pressure has been established in the space 53 and the ' passages communicating therewith, the neddle valve 67 is opened so that the passages 65, 66 are interconnected. If there should.now arise a break of the outer hose 55 the pressure will sink in the space 53. Correspondingly, the pressure will sink in this space if the inner hose should break. For the valve s designed to have a higher pressure in the space 53 than that prevailing in the hos or conduit 54. At a pressure reduction in the space 53 the piston 49 will be pressed downwards by the spring 50. At the same time the valve member 45 will actuate the valve rod 57, thus unseating the ball 58 from its seat .60. There now occurs an instantaneous relief of the. pressure in the space - 53 by the pressure medium flowing through the passages 62, 63, 67 and 66 to the collecting. container 61. At this instantaneous relief the pressure spring will ra- pidly move the valve member 45 down towards its seat 44 so that the valve is closed. The embodiments of the invention described above are only meant as examples, and many variations are possible within the scope of the appended claims.

Claims: CLAIMS 1. A conduit-break valve for a pressure conduit or hose (10, 54) with a surrounding protective conduit or hose (11, 55) and with a space (26, 53) between said conduits or hoses, comprising a valve member (16, 45) yieldingly urged towards its closed position, which valve member is movable in a valve housing (12, 40) between an open position and a closed position prevent¬ ing throughflow through the valve and which is adapted to be actuated in response to a pressure medium in the space (26, 53) between the two conduits or hoses (10, 54 and 11, 55, respectively) , c h a r a c t e r i s e d in that the valve is adapted to operate under a higher pressure in the space (26, 53) between the two conduits or hoses (10, 54) than that prevailing in the pressure conduit or hose and than that of the ambient atmosphere, and that the valve member (16, 45) is connected to a piston or diaphragm device (18, 49) , the piston or dia¬ phragm (18, 49) of which defines a pressure chamber (22, 48) communicating with the space (26, 53) between the two conduits or hoses (10, 54 and 11, 55, respec¬ tively) and is adapted normally to maintain the valve member (16, 45) in its open position. 2. A valve as claimed in claim 1, c h a r a c ¬ t e r i s e d by a sensing and pressure relief mecha- nism which is adapted to sense the position of the valve member (45) and upon displacement of the valve member from its open position towards its closed position to relieve the pressure in the pressure chamber (48) for quick closing of the valve. 3. A valve as claimed in claim 2, c h a r a c ¬ t e r i s e d in that the sensing and pressure relief mechanism (57-60) is designed as a mechanical relief valve (57-60) with a valve member (58) urged towards its closed position and having a valve rod (57) which OMPI is adapted to be actuated by the valve member (45) of the- conduit-break valve and. to be unseated by it from its seat "(60) . 4. A valve as claimed in claim 1, c h a r a c - t e r i s e d by a quick release device which is adapted quickly to relieve the pressure in the pressure chamber (22) at an initial displacement of the valve member (16) towards its valve seat (15) and which comprises a relief valve (31-33) the valve member (31) of which is connected to or formed in an integral piece with the piston or the holder (18) of the diaphragm (21) and normally closes a passage (30) communicating with the space (26) between the two conduits or hoses (10, 11) , and which is adapted, at a reduction of the pres- sure in the pressure chamber, to be unseated from its seat and connect said passage to the ambient atmosphere. OMPI

Inventors: PALMGREN KARL SIEVERT, PALMGREN, KARL, SIEVERT
Applicants: REGIONINVEST I NORR AB
Application year: 1983
Main classification: F17D5
IPC codes: F16K17, F17D5