The invention is related to a method of testing a gas shut-down valve for a combustion engine for leakages at the valve seat and at a sealing ring surrounding the valve.
WO 9824014 describes a system of testing fuel injection valves by means of pressurized gas. Such a system is not sufficient for testing of gas shut-down valves for combustion engines where even the smallest leakages are unacceptable and may result in an explosion.
A system of testing of gas injection valves is also known. This system is however not satisfactory.
Finally GB 1285705 describes an apparatus for testing a valve. The valve is placed in a holder and the valve is in closed condition influenced by a not burnable pressurized gas to check whether the valve seat is closed. However this apparatus is not designed for testing of a valve which is surrounded by a sealing ring when it is in operation.
According to the invention the valve with the surrounding sealing ring is placed in a chamber of a holder so that the chamber due to the sealing ring is divided into a first portion and a second portion including the valve seat, and the valve is in closed condition influenced by a non-burnable gas under pressure, the test gas being supplied to the second portion of the chamber. As a result the test gas can seep into the first portion of the chamber if the valve seat and/or the sealing ring are leaky. The test gas may according to the invention be supplied to the second portion of the chamber at a pressure of about 300 bar, the rest of the valve being supplied with sealing oil at a pressure higher than the gas pressure. As a result the test gas is prohibited from entering the valve.
In a special advantageous embodiment the test gas may be composed of nitrogen.
The valve may according to the invention be opened by means of control oil supplied to the valve.
In a special advantageous embodiment the pressure of the test gas may be increased to above 300 bar by means of a compressor driven by means of the said control oil. Finally according to the invention the gas which during the supply of gas to the second portion of the chamber escapes through the valve seat and/or the sealing ring of the valve, may be detected through a to the first portion of the chamber connected gas discharge tube which is connected to a separate container with liquid.
The invention is also related to a system of testing a gas shut-down valve for a combustion engine comprising a holder with a chamber, in which the valve can be placed, said system also comprising a unit for supplying of sealing oil to the valve, a unit for supplying of control oil to the valve, a unit for supplying of test gas to the holder and a unit for testing the valve for leakages at the valve seat and/or the sealing ring. As a result the valve could be tested during circumstances corresponding to circumstances when the valve is in operation.
The invention will be described in the following with reference to the drawings in which
Gas shut-down valves for combustion engines such as two-stroke engines has to be checked regularly and very often due to the fact that leakages if any may give occasion for escape of explosive gasses. The opening and closing functions of the valve also have to be checked.
The holder 1 in which the valve is placed, conf.
The slide 13 may be displaced in downward direction by applying pressurized control oil through channels 16 in the top piece 3 to the over side of the body 14 surrounding the slide 13 and from there through small grooves 14a in the over side of the body 14 to a cavity in the top piece 3 over the top (piston B) of the rod formed portion of the slide 13. The body 14 surrounding the slide 13 acts in itself as a piston (piston A). By applying of control oil the oil pressure will activate piston A and piston B at the same time. The flow of oil passes from the underside of the piston A through the grooves 14a in the over side of piston A to the center from where the oil is guided up to piston B. As a result there is a pressure at a relatively large area (piston A). As a result the disk valve 9 opens by overcoming the gas pressure at the disk valve 9. However the piston A only has a short downward movement of about 0.5 mm. before the underside of the piston A contacts a bottom face. To operate as intended the piston A has to be surrounded by a sealing ring 14b. When the displacement of the piston A stops, the piston B continues by opening the gas valve and the gas valve is completely open when the displacement of about 10 mm. of the piston B stops in the bottom of the cavity in piston A. The pressure area at piston B is essentially smaller, as the pressure at piston B only has to overcome the pressure of the spring 11 to keep the gas valve open. The supply of control oil is controlled by means of a slide valve 25 in the pipe for supplying of control oil.
As previously mentioned there is also an opening 17 in the bottom of the holder 3, conf.
All the portions of the holder 1 are secured to flanges 42 kept together by means of bolts 41.
The placement of the valve in the holder 1 corresponds to the placement in a combustion engine, typically a two-stroke engine.
In a special advantageous embodiment the pressure of the test gas is increased to about 300 bar by means of the compressor 29 in the pipe for supplying of gas.
A ventilation is made before use by means of the non-burnable test gas under pressure so as to remove remaining oxygen in the chambers of the holder, as such remaining oxygen otherwise could cause an explosion.
Number | Date | Country | Kind |
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2012 00140 | Feb 2012 | DK | national |
Filing Document | Filing Date | Country | Kind |
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PCT/EP2013/000316 | 2/1/2013 | WO | 00 |
Publishing Document | Publishing Date | Country | Kind |
---|---|---|---|
WO2013/124035 | 8/29/2013 | WO | A |
Number | Name | Date | Kind |
---|---|---|---|
20080314120 | Maier et al. | Dec 2008 | A1 |
20150007639 | Kortsen | Jan 2015 | A1 |
Number | Date | Country |
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101858818 | Oct 2010 | CN |
5980073 | May 1984 | JP |
62198727 | Sep 1987 | JP |
62173546 | Nov 1987 | JP |
2009156600 | Jul 2009 | JP |
2011220195 | Nov 2011 | JP |
WO2011160317 | Dec 2011 | WO |
Entry |
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Office Action dated May 23, 2016 from Chinese patent application No. 201380010072.8. |
Office Action dated Jul. 25, 2016 from Japanese patent application No. 2014558030. |
Office Action dated Jun. 21, 2016 from Korean patent application No. KR1020147021191. |
Number | Date | Country | |
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20150007639 A1 | Jan 2015 | US |