Continuous magnetic motion position indicator

Abstract

A continuous magnetic motion position indicator detects the position of a clapper valve. The clapper valve comprises a valve body and, disposed within the valve body, a clapper and a valve stem. The continuous magnetic motion position indicator comprises: (a) a magnetic joint assembly comprising a first set of magnets disposed inside the valve body and a second set of magnets located outside the valve body that operatively interface with the first set of magnets, and (b) a remote position transmitter and/or a local visual indicator. In operation, the magnetic joint assembly transmits rotary movement of the clapper from the valve stem to the remote position transmitter and/or local visual indicator, without the presence of a dynamic seal interface.

Claims

1. A subsea clapper-valve indicator system comprising: (a) a clapper valve comprising: (i) a valve body with a static seal; (ii) a clapper; and (iii) a clapper valve stem keyed to said clapper; (b) a continuous magnetic motion position indicator configured for detecting the instantaneous position of said clapper comprising: (i) a magnetic joint assembly comprising a first set of magnets disposed inside a pressure containing cap affixed to said valve body, said first set of magnets being contained in an internal magnet housing, and a second set of magnets contained in an external magnet housing, located outside said pressure containing cap, said second set of magnets operatively interfacing with said first set of magnets, wherein said internal magnet housing is keyed on a valve shaft, and said valve shaft interacts with said clapper valve stem; (ii) a gear set comprising: (1) a first gear keyed on the top of said external magnet housing, (2) a second gear meshing with said first gear; and (3) a third gear meshing with said first gear; (iii) a remote position transmitter, said remote position transmitter being keyed on said second gear, whereby said magnetic joint assembly transmits rotary movement of said clapper to said remote position transmitter; (iv) a local visual indicator, said local visual indicator being keyed on said third gear, whereby said magnetic joint assembly transmits rotary movement of said clapper to said local visual indicator.

2. The system of claim 1 wherein said first set of magnets are permanent magnets.

3. The system of claim 1 wherein said first set of magnets includes eight magnets.

4. The system of claim 1 wherein said first set of magnets are arranged in an alternating pattern.

5. The system of claim 1 wherein said second set of magnets and said remote position transmitter can be removed from said continuous magnetic motion position indicator without affecting the functionality of said valve body.

6. A method of detecting the position of a clapper in a clapper valve in a subsea environment, wherein said clapper valve comprises a valve body with a static seal and, disposed within said valve body, a clapper keyed on a clapper valve stem, said method comprising: (a) disposing a first set of magnets contained in an internal magnet housing inside a pressure containing cap affixed to said valve body and a second set of magnets outside said pressure containing cap affixed to said valve body that operatively interface with said first set of magnets to form a magnetic joint assembly, wherein said internal magnet housing is keyed on a valve shaft interacting with said clapper valve stem and wherein said second set of magnets is contained in an external magnet housing; (b) disposing a gear set comprising a first gear on the top of said external magnet housing, a second gear meshing with said first gear, and a third gear meshing with said first gear; (c) placing a remote position transmitter such that said remote position transmitter indicator is keyed on said second gear; (d) transmitting rotary movement of said clapper to said remote position transmitter through said first and second set of magnets and said gear set; (e) placing a local visual indicator such that said local visual indicator being keyed on said third gear; and (f) transmitting rotary movement of said clapper to said local visual indicatorthrough said first and second set of magnets and said gear set.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) FIG. 1 is a perspective cutaway sectional view of the present Continuous Magnetic Motion Position Indicator (CMMPI).

(2) FIG. 2 is a top view of the CMMPI illustrated in FIG. 1.

(3) FIG. 3 is cross-sectional view of the present CMMPI, taken in the direction of arrows A-A in FIG. 2.

(4) FIG. 4. is cross-sectional view of the present CMMPI, taken in the direction of arrows B-B in FIG. 2.

(5) FIG. 5 is a cross-sectional view of the present CMMPI, taken in the direction of arrows C-C in FIG. 3.

(6) FIG. 6 is a perspective view of the present CMMPI.

(7) FIG. 7 is a perspective cutaway sectional view of the CMMPI of FIG. 1 showing the shaft connected to the clapper.

(8) FIG. 8 is a perspective cutaway view of a CMMPI in some embodiments showing a visually enhanced local visual indicator and a remote position indicator.

(9) FIG. 9 is a perspective view of a CMMPI and clapper valve in some embodiments.

(10) FIG. 10 is a perspective cutaway view of a CMMPI and a clapper valve in some embodiments.

(11) FIG. 11 is a perspective cutaway view of a CMMPI and a clapper valve in some embodiments.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENT(S)

(12) FIG. 1 shows a continuous magnetic motion position indicator (CMMPI) 1 for subsea and topside applications. CMMPI 1 enables the monitoring of the instantaneous position of the clapper through valve shaft 2, including free-swinging motion.

(13) As further shown in FIG. 1, CMMPI 1 includes a housing 10 connected to pressure-containing cap 28 and valve body 4 using fixing bolts 8 and nuts 40. External magnet set 26 is contained in an external magnet housing 24 and internal magnet set 30 is contained in an internal magnet housing 32. External and internal magnet sets 26 and 30, respectively, transfer the rotation of the clapper through valve shaft 2 to a local visual indicator 18a and/or remote position transmitter 18b outside the pressure-containing parts and contained in cover 16. The position of the clapper can thereby be detected without introduction additional dynamic seal interfaces in valve body 4 and instead allows valve body 4 to utilize a static seal 6. The transfer of motion from the magnetic sets 26 and 30 to a local visual indicator 18a and/or remote position transmitter 18b is accomplished by way of gear sets 22, which are located in gear sets housing 14.

(14) FIG. 2 is a top view of CMMPI 1 showing cover 16, as well as local visual indicator 18a and/or remote position transmitter 18b. Arrows A-A identify the bisecting line for the cross-sectional view illustrated in FIG. 3. Arrows B-B identify the bisecting line for the cross-sectional illustrated in FIG. 4.

(15) FIG. 3 shows a cross-sectional views of CMMPI 1, taken in the direction of arrows A-A in FIG. 2. FIG. 4 shows a cross-sectional views of CMMPI 1, taken in the direction of arrows B-B in FIG. 2. FIGS. 3 and 4 specifically illustrate the connections among the various components of CMMPI 1. Roller bearings 12 are utilized throughout the CMMPI 1 to facilitate movement, while pins 34 facilitate the attachment of cover 16 to gear set housing 14. Pins 34 also facilitate the attachment of gear set housing 14 to housing 10, as well as the attachment of pressure-containing cap 28 to valve body 4 (see FIG. 1). Bolts 8 and nuts 40 facilitate the attachment of housing 10 to pressure-containing cap 28 and valve body 4. FIG. 4 also shows flange 36 and hexagonal screw 38.

(16) FIG. 5 is a cross-sectional view of the present CMMPI, taken in the direction of arrows C-C in FIG. 3. FIG. 5 illustrates the placement of internal magnet set 30 and external magnet set 26. The eight internal magnets 30 are arranged alternatingly, with an internal magnet with the positive pole facing down depicted in FIG. 5 as internal magnet 30a and an internal magnet with the negative pole facing down depicted as internal magnet 30b. Similarly, the eight external magnets 26 are arranged alternatingly, with an external magnet with the positive pole facing down depicted in FIG. 5 as external magnet 26a and an external magnet with the negative pole facing down depicted as external magnet 26b.

(17) FIG. 6 is a perspective view of the CMMPI 1 showing local visual indicator 18a and/or remote position transmitter 18b, gear set housing 14, housing 10, and pressure-containing cap 28.

(18) FIG. 7 illustrates shaft 2 of CMMPI 1 connected to clapper 50. CCMPI 1 is configured to be used with non-returning valves such as swing check valves, tilting valves and dual-plate valves. Non-returning valves are composed of a rotating stein where clapper 50 (often referred to as an obturator) is pivotally mounted to valve body via a shaft/hinge pin and its shaft housing. CCMPI 1 transfers the motion of clapper 50 through the shaft/hinge pin outside the pressure boundary.

(19) FIG. 8 illustrates a CMMPI having local visual indicator 18a and remote position transmitter 18b in an embodiment where large indicators and transmitters are desired for easy reading and maintenance.

(20) FIG. 9 illustrates a CMMPI keyed to clapper valve 210 (generally indicated) via valve shaft 2 interacting with clapper valve stem 3.

(21) FIG. 10 illustrates a CMMPI keyed to a clapper valve 210 via valve shaft 2 interacting with clapper valve stem 3, further showing clapper valve stem 3 connected to clapper 200 comprising clapper valve 210.

(22) FIG. 11 illustrates a CMMPI connection between valve shaft 2 and clapper valve stem 3, wherein the CMMPI is affixed to valve body 4 of generally indicated clapper valve 210.

(23) The present continuous position indicator has the following advantageous features: (a) the present CMMPI allows the monitoring of the instantaneous position of the clapper in various positions, including the free swinging motion; (b) the present CMMPI can be implemented in top side and subsea valve applications; (c) the present CMMPI does not include dynamic sealing interface(s), which could introduce potential leakage paths through the valve body; (d) in the present CMMPI, the position transmitters and the external set of magnets can be readily removed and replaced from the outside of the valve body without detrimentally affecting the functioning of the valve.

(24) While particular elements, embodiments and applications of the present invention have been shown and described, it will be understood, that the invention is not limited thereto since modifications can be made by those skilled in the art without departing from the scope of the present disclosure, particularly in light of the foregoing teachings.