Technical field of the invention

The present invention relates to a shut-off valve for connecting a pressure sensor to a fluid system of a piston engine in accordance with the preamble of claim 1 .

Background of the invention

A large internal combustion engine, such as a ship engine or a power plant engine is typically provided with several pressure sensors that are used for monitoring pressure in different systems of the engine. For instance, a fuel gas system of a gas engine is provided with a pressure sensor for measuring the pressure of the gaseous fuel. The pressure sensors can be connected to the fluid systems where pressures need to be monitored via pressure gauge valves. A pressure gauge valve establishes fluid communication between a flu- id system and a pressure sensor and has a shut off -functionality, which allows disconnection of the pressure sensor from the fluid system. A problem with the existing pressure gauge valves is that the pressure sensor can be attached to the pressure gauge valve in a certain position only. Pressure gauge valves can also suffer from vibration problems.

Summary of the invention

An object of the present invention is to provide an improved shut-off valve for connecting a pressure sensor to a fluid system of a piston engine. The characterizing features of the shut-off valve according to the invention are given in the characterizing part of claim 1 .

The valve according to the invention is provided with an inlet for exposing the valve to the pressure in the fluid system, with an outlet for exposing the pressure sensor to the pressure inside the valve, and with a fluid channel for connecting the outlet to the inlet. The valve comprises a body, a valve member that is movable between an open position and a closed position, the valve be- ing configured to allow flow between the inlet and the outlet in the open position of the valve member and to prevent flow between the inlet and the outlet in the closed position of the valve member, and a fastening element, which is configured to attach the body of the valve to a component of the fluid system, the fastening element forming part of the fluid channel. The valve member is arranged coaxially with the fastening element and at least partly inside the fastening element.

The design of the shut-off valve allows a more compact construction, which resists vibrations. It also provides different ways to position the pressure sensor. According to an embodiment of the invention, the outlet is arranged in a plane that is perpendicular to the plane in which the inlet is arranged.

According to an embodiment of the invention, the outlet is arranged in a plane that is perpendicular to the axial direction of the fastening element.

According to an embodiment of the invention, the valve comprises at least two outlets, which face different directions relative to each other. The outlets can face opposite directions.

According to an embodiment of the invention, the fastening element is configured to be inserted through the body of the valve and one end of the fastening element is provided with a threaded portion for engaging the fastening element with a thread in a part of the fluid system.

According to an embodiment of the invention, the valve member is movable in the axial direction of the fastening element.

A pressure sensor arrangement according to the invention comprises a shut- off valve defined above and a pressure sensor connected to the shut-off valve. A piston engine according to the invention comprises a fluid system and a pressure sensor arrangement defined above connected to the fluid system. The fluid system can be a fuel gas system. Brief description of the drawings

Embodiments of the invention are described below in more detail with reference to the accompanying drawings, in which

Fig. 1 shows a pressure sensor arrangement comprising a shut-off valve ac- cording to an embodiment of the invention and a pressure sensor,

Fig. 2 shows the shut-off valve of fig. 1 ,

Fig. 3 shows a cross-sectional view of the shut-off valve of figures 1 and 2,

Fig. 4 shows a shut-off valve according to another embodiment of the invention, Fig. 5 shows a pressure sensor arrangement that comprises two pressure sensors connected to a single shut-off valve, and

Fig. 6 shows a cross-sectional view of the shut-off valve of fig. 5.

Description of embodiments of the invention Figure 1 shows a pressure sensor arrangement according to an embodiment of the invention. The pressure sensor arrangement comprises a pressure sensor 1 , which is attached to a shut-off valve 2. The pressure sensor 1 is used for monitoring pressure in a fluid system of a piston engine. The engine is a large internal combustion engine, such as a main or an auxiliary engine of a ship or an engine that is used at a power plant for producing electricity. The fluid system can be, for instance, a fuel gas system of a gas engine or a dual-/multi-fuel engine, a pneumatic system or some other system containing pressurized gas or liquid. The shut-off valve 2 can be used for closing fluid connection between the fluid system and the pressure sensor 1 . This allows the pressure sensor 1 to be removed or replaced by another pressure sensor 1 .

The shut-off valve 2 of figure 1 is also shown in figure 2. Details of the shut-off valve 2 can be best seen in figure 3, which shows a cross-sectional view of the shut-off valve 2. The shut-off valve 2 is provided with an inlet 3 and an outlet 4. The inlet 3 is connected to a component of the fluid system for exposing the shut-off valve 2 to the pressure in the fluid system. The outlet 4 is connected to the pressure sensor 1 for exposing the pressure sensor 1 to the pressure inside the shut-off valve 2. A fluid channel 5 inside the shut-off valve 2 connects the outlet 4 to the inlet 3. In the embodiments of the figures, the outlet 4 is arranged in a plane that is perpendicular to the plane in which the inlet 3 is ar- ranged.

The shut-off valve 2 comprises a body 6, a valve member 7 and a fastening element 8. The body 6 of the shut-off valve 2 can be made of steel or some other suitable alloy. The body 6 can be a one-piece part. The valve member 7 is a movable part. It can be moved between an open position and a closed posi- tion. In the open position, the valve member 7 allows flow between the inlet 3 and the outlet 4 of the shut-off valve 2, and in the closed position the valve member 7 prevents flow between the inlet 3 and the outlet 4. The fastening element 8 is used for attaching the shut-off valve 2 to a component of a fluid system. The fastening element 8 is a threaded part that is configured to protrude into an opening in a component of the fluid system. The thread of the fastening element 8 can be engaged with a thread of the component of the fluid system. The fluid channel 5 of the shut-off valve 2 is arranged partly inside the fastening element 8. The fluid channel 5 comprises a first section 5a, which is formed inside the fastening element 8, and a second section 5b, which is formed inside the body 6 of the shut-off valve 2. In the embodiments of the figures, the second section 5b of the fluid channel 5 is perpendicular to the first section 5a.

In the embodiments of the figures, the fastening element 8 is an elongated part having a first end and a second end. The first end of the fastening element 8 is inserted through the body 6 of the shut-off valve 2. The length of the fastening element 8 is greater than the thickness of the body 6 of the shut-off valve 2 so that the first end of the fastening element 8 protrudes out of the body 6. The first end of the fastening element 8 is provided with a threaded portion 8a. The thread is arranged on an outer surface of the fastening element 8 and can be engaged with an internal thread of a component of the fluid system. The fastening element 8 is provided with a flange 8b. In the embodiments of the figures, the flange 8b is arranged at the second end of the fastening element 8. The flange 8b clamps the body 6 of the shut-off valve 2 against the component of the fluid system. In the embodiment of figures 1 and 3, a sealing ring 9 is ar- ranged around the fastening element 8. The sealing ring 9 is clamped between the body 6 of the shut-off valve 2 and the part of the fluid system to which the shut-off valve 2 is attached.

The fastening element 8 is a hollow part. The fastening element 8 is provided with an axial fluid channel 5a, which forms the first section of the fluid channel 5 of the shut-off valve 2. The first end of the fastening element 8 is provided with an opening, which forms the inlet 3 of the shut-off valve 2. Also the second end of the fastening element 8 is open. The side wall of the fastening element 8 is provided with at least one opening 10. The opening 10 allows outflow from the fluid channel 5a of the fastening element 8. An annular space 16 be- tween the body 6 and the fastening element 8 connects the opening 10 to the second section 5b of the fluid channel 5.

The valve member 7 is coaxial with the fastening element 8. The valve member 7 protrudes into the fastening element 8 and it is thus partly inside the fastening element 8. The valve member 7 can be inserted into the fastening ele- ment 8 through the second end of the fastening element 8. The valve member 7 can be moved in the axial direction of the fastening element 8. The valve member 7 has a first end and a second end. The first end of the valve member 7 faces the same direction as the first end of the fastening element 8. The first end of the valve member 7 is provided with a sealing surface 1 1 . In the embod- iments of the figures, the sealing surface 1 1 is conical. The sealing surface 1 1 of the valve member 7 can be brought into contact with a valve seat 12 that is formed in the fastening element 8. When the sealing surface 1 1 is arranged in contact with the valve seat 12, the valve member 7 is in the closed position. In figure 3, the valve member 7 is shown in the open position. In the embodiments of the figures, the shut-off valve 2 is provided with a sleeve 13, which is arranged partly inside the fastening element 8 at the second end of the fastening element 8. The sleeve 13 is attached to the fastening element 8 by means of an external thread 20. The fastening element 8 is provided with a corresponding internal thread 21 . The valve member 7 is inserted into the sleeve 13. The valve member 7 is provided with an external thread 18 and the sleeve 13 is provided with an internal thread 19. As the valve member 7 is rotated in respect of the sleeve 13, it is moved in the axial direction of the sleeve 13 and the fastening element 8. By rotating the valve member 7, it can be moved between the open position and the closed position. In the open posi- tion of the valve member 7, flow from the first section 5a of the fluid channel 5 via the opening 10 in the wall of the fastening element 8 into the second section 5b of the fluid channel 5 is allowed.

The body 6 of the shut-off valve 2 comprises mounting holes 17, which can be used for fastening the pressure sensor 1 to the shut-off valve 2. In the embod- iments of figures 1 to 4, the shut-off valve 2 is provided with four mounting holes 17. The mounting holes 17 are positioned so that the pressure sensor 1 can be attached to the shut-off valve 2 in different positions depending on the application. In figure 1 the pressure sensor 1 is in a vertical position, but it could also be arranged in a horizontal position. The pressure sensor 1 is at- tached to the shut-off valve 2 with two bolts 22. It depends on the mounting position, which two of the mounting holes 17 are used for attaching the pressure sensor 1 to the shut-off valve 2.

In the embodiment of figure 4, the shut-off valve 2 is similar to the shut-off valve of figures 1 to 3. However, instead of the sealing ring 9, an O-ring 14 is arranged around the fastening element 8. The body 6 of the shut-off valve 2 is provided with a groove 15 for accommodating the O-ring 14. The groove 15 is arranged in the lower surface of the body 6, i.e. the surface that is arranged against the part of the fluid system to which the shut-off valve 2 is attached.

Also the embodiment of figures 5 and 6 is similar to the embodiments of the other figures. However, in the embodiment of figures 5 and 6, the shut-off valve 2 is configured to connect two pressure sensors 2 to the fluid system. The shut-off valve 2 is therefore provided with a first outlet 4a and a second outlet 4b. In the embodiment of figures 5 and 6, the outlets 4a, 4b face opposite directions. An annular space 16 is arranged between the fastening ele- ment 8 and the body 6 of the shut-off valve 2. The outlets 4a, 4b are connected to the fluid channel 5a of the fastening element 8 via the annular space 16 and the opening 10 in the wall of the fastening element 8. As shown in figure 5, the two pressure sensors 1 can be attached to the shut-off valve 2 in different positions. Each side of the shut-off valve 2 is provided with a plurality of mount- ing holes 17. This allows the pressure sensor 1 to be arranged either in a vertical position or a horizontal position by means of bolts 22.

It will be appreciated by a person skilled in the art that the invention is not limited to the embodiments described above, but may vary within the scope of the appended claims.