FI127673B

FI127673B - An arrangement and a method for inserting and removing a head of a measuring device to and from a process space

Info

Publication number: FI127673B
Application number: FI20175540A
Authority: FI
Inventors: Harri Salo
Original assignee: Janesko Oy
Priority date: 2017-06-12
Filing date: 2017-06-12
Publication date: 2018-11-30
Also published as: FI20175540A1; FI20185464A1; FI127748B

Abstract

The invention relates to an arrangement for inserting and removing a head of a measuring device to and from a process space. The arrangement (1) comprising a process space (3), a measuring device (4) comprising a measuring head (2) at its one end and a retractor tool (5), wherein a valve member (6) is connected to the process space (3) and the retractor tool (5) is connected to the valve member (6). The retractor tool (5) comprises rails (7), a cradle (8) for receiving the measuring device (4) and arranged to slide along the rails (7), and a driving mechanism (9) for moving the cradle (8). The arrangement (1) comprises a valve lock mechanism preventing opening of the valve member (6) if the measuring device (4) is not present in the cradle (8), and the head of the measuring device (2) is insertable to the process space (3) and removable from the process space (3) by putting the measuring device (4) in the cradle (8) and operating the driving mechanism (9) and the valve member (6). The invention relates also to a method for inserting and removing a head of a measuring device to and from a process space.

Description

An arrangement and a method for inserting and removing a head of a measuring device to and from a process space

Field of the invention [0001] The present invention relates to an arrangement and a method for inserting and removing a head of a measuring device to and from a process space, and particularly to an arrangement and a method for inserting and removing a head of a measuring device to and from a process space comprising a retractor tool.

Background of the invention [0002] Measuring devices are used in monitoring and managing processes where the process medium may be hot, pressurized, aggressive or otherwise hazardous. If the process is a continuous process with infrequent shutdowns there is a need for servicing and maintenance of the measuring devices while the process line is under full process flow and pressure. The servicing and mainte15 nance may comprise modifying, maintaining, lubricating, cleaning and unjamming the measuring devices.

[0003] There is a need for failsafe and fool proof solutions for servicing and maintenance activities of measuring devices in order to prevent injuries resulting from failure to use practices and procedures necessary. Further, the 20 tools used in handling a measuring device while the process line is under full process flow and pressure should be designed to protect the user.

Brief description of the invention [0004] An object of the present invention is to provide an arrangement and a method to solve the above problems. The objects of the invention are 25 achieved by an arrangement and a method for inserting and removing a head of a measuring device to and from a process space which are characterized by what is stated in the independent claims. The preferred embodiments of the invention are disclosed in the dependent claims.

[0005] The invention is based on the idea of providing an arrange30 ment for inserting and removing a head of a measuring device to and from a process space. The arrangement comprising a process space, a measuring device comprising a measuring head at its one end and a retractor tool. A valve member is connected to the process space and the retractor tool is connected to the valve

20175540 prh 23 -05- 2018 member. The retractor tool comprises rails, a cradle for receiving the measuring device and arranged to slide along the rails, and a driving mechanism for moving the cradle. The arrangement comprises a valve lock mechanism preventing opening of the valve member if the measuring device is not present in the cradle. The 5 head of the measuring device is insertable to the process space and removable from the process space by putting the measuring device in the cradle and operating the driving mechanism and the valve member.

[0006] The invention is based on the idea of providing a method for inserting and removing a head of a measuring device to and from a process space. 10 The method comprises a process space, a measuring device comprising a measuring head at its one end and a retractor tool. A valve member is connected to the process space and the retractor tool is connected to the valve member. The retractor tool comprises rails, a cradle and a driving mechanism, wherein the cradle receives the measuring device and slides along the rails, and the driving mecha15 nism moves the cradle. The method comprises a valve lock mechanism preventing opening of the valve member if the measuring device is not present in the cradle. The head of the measuring device is inserted to the process space and removed from the process space by putting the measuring device in the cradle and operating the driving mechanism and valve the member.

[0007] The arrangement and method provide a failsafe operation and a fool proof construction. The arrangement and the method protect user from spills and splashes during the measuring device insertion and removal.

Brief description of the figures [0008] In the following the invention will be described in greater de25 tail by means of preferred embodiments with reference to the attached drawings, in which

Figure 1 shows an arrangement where a measuring device is uninstalled to a retractor tool;

Figure 2 shows the arrangement in the beginning of the inserting of a 30 head of a measuring device to a process space;

Figure 3 shows the arrangement in the phase of the inserting of the head of a measuring device to the process space;

Figure 4 shows the arrangement in the phase of the opening isolation valve;

Figure 5 shows the arrangement when the head of a measuring device is inserted to the process space;

20175540 prh 23 -05- 2018

Figure 6 shows the arrangement in the phase of the removing of the head of the measuring device from the process space;

Figure 7 shows the arrangement in the phase of the removing of the head of the measuring device from the process space.

[0009] Detailed description of the invention [0010] Figure 1 shows an arrangement 1 for inserting and removing a head of a measuring device 2 to and from a process space 3. The arrangement 1 comprises a process space 3, a measuring device 4 comprising a measuring head 2 at its one end and a retractor tool 5. In Figure 1 the measuring device 4 is shown 10 uninstalled to the retractor tool 5 for a sake of clarity. A valve member 6 is connected to the process space 3 and the retractor tool 5 is connected to the valve member 6. The retractor tool 5 comprises rails 7, a cradle 8 for receiving the measuring device 4 and arranged to slide along the rails 7, and a driving mechanism 9 for moving the cradle 8. The arrangement comprises a valve lock mecha15 nism preventing opening of the valve member 6 if the measuring device 4 is not present in the cradle 8, and the head of the measuring device 2 is insertable to the process space 3 and removable from the process space 3 by putting the measuring device 4 in the cradle 8 and operating the driving mechanism 9 and the valve member 6.

[0011] The process space 3 may be a process pipe, for instance. In the

Figures illustrated process space 3 is a part of a process pipe. The process space 3 contains the fluid 10 to be measured with the measuring device 4. The fluid 10 may be pressurized, hot and/or aggressive. An example of the process space 3 and the fluid 10 is a line comprising black liquor.

[0012] The valve member 6 closes the opening to the process space 3.

The valve member 6 comprising an isolation valve 11, may be attached to the process space 3 in any manner known per se, for example by means of a welded stub pipe and a flange joint. The isolation valve 11 itself may be any type of valve suitable for the process pressure and process fluid, such as a ball valve, a suitable 30 slide valve, etc. The isolation valve 11 isolates process fluid 10 from the surroundings. The valve member 6 comprises a valve handle 12 operating the isolation valve 11, i.e. the valve member 6 is closed or opened by rotating the valve handle

12. The valve member comprises a sealing gasket part 13 for sealing the gap between the measurement device 4 and the valve body.

[0013] The opening and closing of the valve member 6 while the process line is under full process flow and pressure may present a hazard to the user.

20175540 prh 23 -05- 2018

Therefore the arrangement 1 comprises a valve lock mechanism preventing opening of the valve member 6 if the measuring device 4 is not present in the cradle 8.

[0014] A measuring device 4 may be a sensor, an analyser or an optical analyser, for instance. The measuring device 4 is used for monitoring a pro5 cess and/or to manage a process, for instance. The head of measuring device 2 is inserted to the process space 3 to be in contact with the fluid 10 to be measured and the body of the measuring device 14 extends outside the process space 3. The body 14 comprises typically a housing comprising an electronics, a processing unit, or an output unit or any combination of these.

[0015] An optical analyser or an optical sensor may be a refractometer. Refractometers are commonly used to determine the concentration of a dissolved solids by making an optical measurement of a solution’s Refractive Index. The head of an optical analyser or sensor typically comprise an optical window, e.g. a prism, and a temperature sensor which are inserted to the process space to be in contact with the fluid to be measured. The body of an optical analyser or sensor typically comprises one or more of the following: a light source, a camera, an analysis circuit, a processor card.

[0016] The retractor tool 5 is an equipment for inserting and removing the measuring device 4 to and from the process space 3. The head of the 20 measuring device 2 is inserted or removed from the process space 3 and the body of the measuring device 14 extends outside the process space 3 also when the head 2 is in an inserted position. The measuring device 4 is guided and supported by the retractor tool 5.

[0017] The retractor tool 5 is fixed to the valve member 6. If the re25 tractor tool 5 is permanently fixed to the valve member 6 the falling of the retractor tool 5 and the measurement device 4 is fully prevented. The retractor tool 5 allows a synchronized movements between the valve member 6 and the measuring device 4 during the inserting and removing the head of the measuring device 2 to and from the process space 3.

[0018] The retractor tool 5 comprises a rail part. In the rail part the rails 7 form the long sides of the retractor tool 5 and the rails 7 are connected with a cross beam 15. The retractor tool 5 may also comprise more than two rails 7, a third rail may be provided below and between the two rails 7, for instance. In Figures the retractor tool 5 is fixed to the valve member 6 by attaching the ends of the rails 7 to the flange of the isolation valve 25. The retractor tool 5 comprises a moving member, a cradle 8, arranged to slide along the rails 7. The measuring de5

20175540 prh 23 -05- 2018 vice 4 is put in the cradle 8. As the measuring device 4 slides between the rails 7 the rails 7 provide axial guidance resulting in a good alignment of the measuring device 4.

[0019] The retractor tool 5 comprises an open structure. The open 5 structure of the retractor tool 5 provides an improved visibility to the measuring device 4. The retractor tool 5 can comprise a light stainless structure.

[0020] The retractor tool 5 comprises a driving mechanism 9 for moving the cradle 8. An example of the driving mechanism 9 is shown in the Figures. A threaded shaft 16, e.g. a screw bar, is fixed to the cradle 8. A hand-wheel 17 is at10 tached to the rail part. The hand-wheel 17 has a thread nut and the operation of the hand-wheel 17 causes the cradle to move along the rails 7 as the threaded shaft 16 pulls or pushes the end plate of the cradle 18. The hand-wheel 17 can be detachable, for instance, and removed from the arrangement 1 when it is not needed.

[0021] The driving mechanism 9 has preferably a self-locking property, which means that the axial loading caused to the cradle 8 by process space 3 pressure will not cause the cradle 8 moving backwards.

[0022] Figure 2 shows the arrangement 1 in the beginning of the inserting of a head of a measuring device 2 to a process space 3.

[0023] The measuring device 4 is put to the cradle 8 the head of the measuring device 2 facing the process space 3. The measuring device 4 preferably comprises projecting parts 19 and the cradle 8 comprises recesses 20 providing a form locking, i.e. a form locking connection, which is made by at least partially enveloping of the outer contour of the projecting part 19 with the recess 20. The end 25 plate 18 of the cradle 8 prevents tilting of the measurement device 4 when the measuring device 4 rests in the cradle 8. It is also possible to use other attachment means for keeping the measuring device 4 inside the cradle 8 in addition or instead of the presented form locking connection. Examples of other attachment means are locking nuts.

[0024] The rails 7 comprise openings 21 at the corresponding locations where the recesses 20 of the cradle 8 are located when the cradle 8 is in a position where the loading of the measurement device 4 to the cradle 8 can be done. These locations are shown in Figures 1 and 2.

[0025] The rails 7 shown in Figures are having a form of C-channel 35 where two sides are bend to form a C. The cradle 8 shown in Figures comprises two sides 22 connected with an end plate 18. The sides 22 of the cradle 8 are slid6

20175540 prh 23 -05- 2018 ing within the rails 7 where the lower part of the rail 7 prevents the cradle 8 from falling down and the upper part of the rail 7 prevents the cradle 8 from being pulled upwards.

[0026] In the beginning of the inserting of a head of a measuring de5 vice 2 to a process space 3 the isolation valve 11 is in a closed position. The valve lock mechanism prevents the opening of the isolation valve 11. The valve lock mechanism comprises a valve lock part 23 and a valve lock operator 24. The valve lock part 23 is arranged to the valve member 6 and it mechanically prevents rotation of the valve handle 12. The valve handle 12 acts as a part of a safety lock10 ing system of the arrangement 1 as the valve member 6 should not be opened if the measuring device 4 is not at a location where it bars the fluid 10 flow from the process space 3. The valve lock operator 24 is arranged to the measuring device 4. The valve lock part 23 extends above the rails 7.

[0027] The valve lock mechanism is released by moving the cradle 8 containing the measuring device 4 towards the process space 3 and pushing the valve lock part 23 with the valve lock operator 24 causing a rotation of the valve lock part 23 which unlocks a rotation of the valve handle 12.

[0028] In the Figures the valve lock part 23 is a pivoting elongated part connected to an isolation valve flange 25. The valve lock operator 24 com20 prises a protruding part, a pin. The protruding part is formed to the body of the measuring device 14 extending outside the valve member 6 when the head of the measuring device 2 is in the inserted position in the process space 3. In Figures the protruding part is formed to an outer surface of a flange of the measuring device 26. The valve lock mechanism provides a synchronized operation between 25 the rotation of the valve handle 12 and the axial movement of the measuring device 4.

[0029] Figure 3 shows the arrangement in the phase of the inserting of a head of a measuring device 2 to a process space 3. The driving mechanism 9 has moved the cradle 8 containing the measuring device 4 towards the process 30 space 3. The head of the measuring device 2 has arrived in the sealing gasket part 13 of the valve member 6. The sealing gasket part 13 provides sealing between the measuring device 4 and the isolation valve body.

[0030] The isolation valve 11 is still in a closed position. As the measuring device 4 has entered the sealing gasket part 13 of the valve member 6 it is 35 safe to start opening the isolation valve 11 and the valve lock mechanism can be released.

20175540 prh 23 -05- 2018 [0031] The valve lock mechanism is released with the protruding part of the valve lock operator 24. When the protruding part of the valve lock operator 24 reaches the valve lock part 23 and moves forward it pushes the valve lock part 23. The pushing of the valve lock part 23 causes the valve lock part 23 to rotate 5 which rotation moves the end of the valve lock part 23 away from blocking the rotation of the valve handle 12.

[0032] The arrangement 1 preferably comprises a guide plate T1 comprising a guide groove 28 extending above the rails 7. The protruding part of the valve lock operator 24 can move in the guide groove 28 which provides side10 ways support.

[0033] The arrangement 1 preferably comprises a collision prevent part 29 preventing the measuring device 4 from colliding with a closed valve member 6 in the insertion phase. The head of the measuring device 2 comprises sensitive parts and there is a risk of damage if a collision occurs. The collision 15 prevent part 29 is attached to the valve handle 12 and when the isolation valve 11 is closed it slides over the guide groove 28.

[0034] Figure 4 shows the arrangement in the phase of the opening isolation valve. In Figure 4 the valve handle 12 of the isolation valve 11 is rotated. As the isolation valve 11 is opened the pressure from the process space 3 pushes 20 the measuring device 4 against the cradle 8 and the driving mechanism 9.

[0035] The collision prevent part 29 pivoted to the valve handle 12 has moved along the valve handle 12 exposing the guide groove 28. The head of the measuring device 2 moves through the valve member 6 when the isolation valve 11 is open.

[0036] In Figure 5 the measuring head of the measuring device 2 is inserted in the process space 3. The measuring head 2 extends into the process space 3 and the measuring head 2 is in contact with fluid 10 to be measured contained in the process space 3 or flowing therein.

[0037] The flange of the measuring device 26 is attached to the isola30 tion valve flange 25. The joint can comprise a bolt- and -screw joint, for instance.

The joint between the measuring device 4 and the isolation valve 11 receives the pressure from the process space 3.

[0038] Figures 6 and 7 show the removal of the head of the measurement device 2 from the process space 3. Figures 4-1 are also used to describe the 35 removing the head of the measuring device 2 from the process space 3 as even

20175540 prh 23 -05- 2018 though the operation of the arrangement 1 is the opposite the locations of the arrangement 1 parts are similar in the removal and insertion processes.

[0039] In Figure 6 the isolation valve 11 is fully open. The joint between the measuring device 4 and the isolation valve 11 is unlocked and the pres5 sure from the process space 3 pushes the measuring device 4 against the cradle 8 and the driving mechanism 9. The driving mechanism 9 is moving the cradle 8 away from the process space 3.

[0040] The valve handle 12 preferably comprises a stop bar 30 at its axial side. The stop bar 30 comprises a slot 31 at its end for the valve lock opera10 tor 24. The valve handle 12 can be rotated when the protruding valve lock operator 24 can pass through the slot 31. At the location where the protruding valve lock operator 24 can pass through the opening the head of the measuring device 2 is in the sealing gasket part 13 of the valve member 6. This location of the protruding valve lock operator 24 is shown in Figure 7. Otherwise the stop bar 30 15 blocks the movement of the valve handle 12 when it hits the protruding valve lock operator 24.

[0041] The aim of the stop bar 30 is to prevent the closing of the closure element 33 of the valve member 6 by turning the valve handle 12 when the measuring device 4 is at the operation area of the closure element 33. The stop 20 bar 30 protects both the valve closure element 33 and the measuring device 4 as both of them could be damaged if the closure element 33 is trying to close while the measuring device 4 is in the closure element 33 opening.

[0042] The stop bar 30 extends in axial direction when the valve member 6 is open and it provides also guiding to the measuring device 4 compris25 ing the valve lock operator 24 by supporting the valve lock operator 24 sideways.

[0043] In Figure 7 the isolation valve 11 is still fully open. The valve handle 12 preferably comprises a stopper 32 at its end. The stopper 32 halts the movement of the measuring device 4 and the cradle 8 at a location when the head of the measuring device 2 is outside the isolation valve 11. At the location of the 30 halting, the head of the measuring device 2 is in the sealing gasket part 13 of the valve member 6 where it bars the fluid 10 flow from the process space 3. The stopper 32 prevents the removal of the head of the measuring device 2 from the valve member 6 when the closure element 33 of the valve member 6 is open thereby protecting the user from a fluid spill from the process space 3.

[0044] In Figure 7 the valve handle 12 is parallel to the guide groove and above the guide groove 28. The end of the valve handle 12 comprises a

20175540 prh 23 -05- 2018 wall part, the stopper 32, extending downwards towards the measuring device 4. As the protruding part of the valve lock operator 24 moves in the guide groove 28 it is halted by the wall part.

[0045] The valve handle 12 is then rotated to close the isolation valve

11. This phase is shown in Figure 4 where the rotation of the valve handle 12 is now made to opposite direction than in the case of insertion. By the rotation of the valve handle 12 the stopper 32 is moved out of a way to permit the valve lock operator 24 continue moving away from the process space 3 in the guide groove 28.

[0046] When the isolation valve 11 is closed the pressure from the process space 3 pushes against the closure element 33 of the valve member 6. The closure element 33 of the valve member 6 is shown in Figure 7 by cutting a part of the body of the valve member 6 surrounding the closure element 33 away. The shown isolation valve 11 is a ball valve where the closure element 33 comprises a 15 ball.

[0047] When the valve handle 12 is rotated to close the valve member 6 the collision prevent part 29 pivoted to the valve handle 12 is sliding over the guide groove as shown in Figure 3. Also the protruding part of the valve lock operator 24 is reaching the valve lock part 23 and it pushes the valve lock part 23 20 causing a rotation of the valve lock part 23 which locks the rotation of the valve handle 12 as shown in Figure 2. The valve lock part 23 can be spring-loaded to ensure its operation.

[0048] In Figure 2 the driving mechanism 9 has moved the cradle 8 containing the measuring device 4 to a location where the form locking connec25 tion is open and the measuring device 4 can be pulled out from the cradle 8.

[0049] The valve lock operator 24 acts in several safety creating functions in the arrangement 1. The valve lock operator 24 operates the valve lock mechanism, and co-operates with the stop bar 30 and the stopper 32. In Figures the valve lock operator 24 is shown as a one part. However, the valve lock opera30 tor 24 can comprise two parts, for instance, arranged axially one after each other.

The axial length of the valve lock operator 24 depends on the axial length of the sealing gasket part 13 as it is relevant that the head of the measuring device 2 is within the sealing gasket part 13 when opening and closing the valve member 6.

[0050] The valve member 6, the measuring device 4 and the traction 35 tool 5 are positioned in one side of the process space 3. In the arrangement 1 shown in the process space 3 comprises one opening for the connection between the fluid 10 in the process space 3 and the head of measuring device 2. The operation from one side of the process space 3 saves also space needed for operating the arrangement.

[0051] The arrangement is advantageous for measuring devices used 5 in in-line measurements. The arrangement provides a fool proof and a failsafe construction.

[0052] It will be obvious to a person skilled in the art that, as the technology advances, the inventive concept can be implemented in various ways. The invention and its embodiments are not limited to the examples described 10 above but may vary within the scope of the claims.

[0053] List of parts: 1 an arrangement; 2 a head of a measuring device, 3 a process space; 4 a measuring device; 5 a retractor tool; 6 a valve member; 7 rails; 8 a cradle; 9 a driving mechanism; 10 fluid; 11 an isolation valve; 12 a valve handle; 13 a sealing gasket part; 14 a body of measuring device; 15 a cross beam;

16 a threaded shaft; 17 a hand-wheel; 18 an end plate; 19 a projecting part; 20 a recess; 21 an opening; 22 a side of a cradle; 23 a valve lock part; 24 valve lock operator; 25 an isolation valve flange; 26 a flange of the measuring device; 27 a guide plate; 28 a guide groove; 29 a collision prevent part; 30 a stop bar; 31a slot; 32 a stopper; 33 a closure element.

Claims

The claims

An arrangement for placing and removing an end of a measuring device in a process space, the arrangement (1) comprising a process space (3), a measuring device (4) comprising a measuring head (2) at one end thereof and a traction device (5), wherein

5 the valve part (6) is connected to the process space (3) and the traction device (5) is connected to the valve part (6), characterized in that the traction device (5) comprises rails (7), the first ends of the rails (7) being connected to the valve flange (25) and the other ends of the rails (7) are connected by a cross beam (15), the carriage (8) to receive the measuring device (4) and arranged to slide along the rails (7), the measuring device (4) is arranged to slide between the rails (7) when received in the carriage (8) and the drive mechanism (9) for moving the carriage (8), and the arrangement (1) comprises a valve locking mechanism comprising a rotating valve locking part (23) preventing the opening of the valve part (6) if the measuring device (4) is not in the carriage (8), and the measuring device head (2) can be placed in the process space (3) and removed from the process space (3) when the measuring device (4) is received in the carriage (8).

An arrangement according to claim 1, characterized in that the valve part (6) comprises an isolation valve (11), a valve handle (12) for operating the isolation valve (11) and a sealing flange part (13).

Arrangement according to Claim 2, characterized in

20 that the valve locking mechanism comprises a valve handle (12), a valve locking portion (23) and a valve lock actuator (24).

Arrangement according to claim 3, characterized in that the valve locking part (23) comprises a pivotable elongate part connected to the valve part (6) and the valve lock actuator (24) comprises a measuring device (4)

25 arranged protruding parts.

Arrangement according to Claim 4, characterized in that the arrangement comprises a collision-preventing part (29) which can be dissolved on the guide groove (28) of the guide plate (27), in which the protruding part of the valve lock actuator (24) is movable. part (29) prevents measuring

30 collision of the device (4) with the closed valve part (6).

Arrangement according to Claim 5, characterized in that the collision-preventing part (29) is pivotally arranged on the valve handle [12).

An arrangement according to any one of claims 2 to 6,

35 characterized in that the valve handle (12) comprises a stopper (32), the movement of the measuring device (4) can be stopped by a stopper (32) and thus the end of the measuring device is prevented

20175540 prh 23 -05- 2018 (2) removal from the valve part (6) with the closing element (33) of the valve part (6) open.

Arrangement according to one of Claims 2 to 7, characterized in that the valve handle (12) has an axial axis of the stop beam (30).

5 and the stop bar (30) comprises an opening (31) at its end for the valve lock actuator (24).

Arrangement according to one of Claims 1 to 8, characterized in that the measuring device (4) has protruding parts (19) and the carriage (8) has recesses (20) providing a form-locking connection between the measuring device (4) and

Between 10 slides (8).

Arrangement according to one of Claims 1 to 9, characterized in that the valve part (6), the measuring device (4) and the traction device (5) are arranged on one side of the process space (3).

Arrangement according to one of Claims 1 to 10, characterized in that the measuring device (4) is a sensor, an analyzer or an optical analyzer.

A method of placing and removing a measuring head in a process space, the method comprising a process space (3), a measuring device (4) comprising a measuring head (2) at one end thereof and a traction device (5), wherein

The valve part (6) is connected to the process space (3) and the drive device (5) is connected to the valve part (6), characterized in that the drive device (5) comprises rails (7), the first ends of the rails (7) being connected to the valve flange (6). (25) and the other ends (7) of the rails (7) are connected by a cross member (15), a carriage (8) and a drive mechanism (9), in which method the carriage (8) receives the measuring device (4) and slides along the rails (7), the measuring device (4) slides between the rails (7) when received on the carriage (8), and the drive mechanism (9) moves the carriage (8), the method comprising a valve locking mechanism comprising a rotating valve locking part (23) preventing the valve part (6) from opening if the measuring device (4) is not in the carriage (8), and the measuring head (2) is placed in the process space (3) and removed from the process space 30 (3) by placing the measuring device (4) in the carriage (8) and using the drive mechanism (9) and the valve part (6).

Method according to claim 12, characterized in that the valve locking mechanism comprises a valve handle (12), a valve locking part (23) arranged in the valve part (6) and a valve lock actuator (24)

35 arranged in the measuring device (4), and the valve locking mechanism is released by moving the carriage (8) containing the measuring device (4) towards the process space (3) by the drive mechanism (9) and pushing the valve locking portion (23) by the valve lock actuator (24) to provide the valve lock a rotation (23) which unlocks the rotation of the valve handle (12).