Description:MAGNETIC CLAMP WITH MPI TESTING MACHINE FOR IDENTIFYING SURFACE AND SUB-SURFACE CRACKS IN VALVE

FIELD OF INVENTION
[0001] The present invention is directed to Magnetic clamp with Magnetic Particle Inspection (MPI) testing machine for identifying surface and sub-surface imperfections in valves for high pressure boilers and Oil Field Equipments.

[0002] The present invention involves Magnetic Particle Inspection (MPI) method applicable for identifying surface and sub-surface imperfections in valves for high pressure boilers and Oil Field Equipments. The invention is particularly related to the method of magnetic clamping instead of manual C clamp. In the proposed invention of “Novel Method for Magnetic Clamping Mechanism for MPI testing in Valve Body”, cycle time reduction and easy handling are achieved.

BACKGROUND OF THE INVENTION

[0003] Background description includes information that may be useful in understanding the present invention. It is not an admission that any of the information provided herein is prior art or relevant to the presently claimed invention, or that any publication specifically or implicitly referenced is prior art.

[0004] In high pressure industrial and power boilers, valves are the critical components in various process controls and safety applications. During manufacturing process, the valve bodies and related components are subjected to non-destructive testing using Magnetic particle inspection (MPI) method in order to identify the surface and subsurface defects / imperfections.

[0005] The Magnetic Particle Inspection (MPI) is a process for detecting surface and slightly subsurface discontinuities in ferromagnetic materials such as iron, nickel, cobalt, and some of their alloys. It is classified into two categories.

[0006] Direct magnetization: In this method, the MPI test current is passed directly through the object and the magnetic field produced is used to detect the subsurface discontinuities.

[0007] Indirect magnetization: In this method, no electric current is directly passed through the object, but a magnetic field is applied from an outside source.

[0008] In the existing MPI equipment the following problems exist:-
1. The high current cables of the MPI equipment, connected to the valve body through “C” clamps are to be changed manually by the NDT inspecting personnel to test different portions of body and in different directions, which results in delay in testing time and also has possibilities for injuries for the inspection persons. For every inspection, minimum 4 nos. of clamping and 4 nos. of de-clamping activities (depending upon the size & shape of valve body) have to be carried out which is tedious in nature, too heavy to handle manually. The corroded nature of the metallic clamps as a result of its exposure to corrosive chemicals over a long period of time makes the process still more difficult.
2. In order to reduce the cycle time and easy handling in clamping, the physical method of clamping is replaced with magnetic clamping mechanism.

Prior Art Search:
[0009] Reference may be made to the following prior art:

[0010] “US9349516B2 2016-05-24: Multidirectional magnetic particle inspection system”

[0011] A magnetic particle inspection system for inspecting a plurality of articles. The system includes a first magnetizing coil for generating a first magnetic field oriented in a first direction. The system also includes a second magnetizing coil for generating a second magnetic field oriented in a second direction perpendicular to the first direction, wherein the first and second magnetizing coils are located in a common plane. In addition, the system may include a mat having a plurality of drainage holes, wherein the first and second magnetizing coils are located in the mat and the first and second magnetizing coils are sized to inspect a plurality of articles. Further, the system includes a power supply for supplying power for energizing the first and second magnetizing coils and a switching unit for switching current flow between the first and second magnetizing coils.

[0012] However, the above mentioned magnetic particle inspection system relates to non-contact type multidirectional magnetic particle inspection testing method but not relevant to the specific requirement of testing of valve bodies of present invention. Hence, the present invention has been proposed.

OBJECTS OF THE INVENTION
[0013] Primary object of the invention is to provide Magnetic clamp with Magnetic Particle Inspection (MPI) testing machine for identifying surface and sub-surface defects in valve for high pressure boilers and components.

[0014] Another objective of the invention is to propose a device having copper bus covered with copper mesh which creates a high conducting media to job instead of physical clamping to the job.

[0015] Further object of the invention is to reduce the time taken for Magnetic Particle Inspection (MPI) testing of valve body.

[0016] These and other objects and advantages of the present invention will be apparent to those skilled in the art after a consideration of the following detailed description taken in conjunction with the accompanying drawings in which a preferred form of the present invention is illustrated.

SUMMARY OF THE INVENTION
[0017] One or more drawbacks of conventional systems and process are overcome, and additional advantages are provided through the apparatus/composition and a method as claimed in the present disclosure. Additional features and advantages are realized through the technicalities of the present disclosure. Other embodiments and aspects of the disclosure are described in detail herein and are considered to be part of the claimed disclosure.

[0018] According to the invention, there is provided Magnetic clamp for identifying surface and sub-surface cracks in valve for high pressure boilers, which includes Magnet (a) attached to a valve body, Aluminium Casting (b) constituting a casing for the magnet(a), Hylem Sheet (c) provided in between the aluminium casting (b) and copper bar/Plate (d), Copper Bar/Plate (d) placed between copper mesh(e) to establish connection between said valve body and ports and Copper Mesh (e) surrounding the copper bar/Plate (d).

[0019] The present invention involves Method for Magnetic Clamping Mechanism for MPI testing in Valve Body, that provides an efficient way for clamping mechanism in valve bodies.

[0020] Various objects, features, aspects, and advantages of the inventive subject matter will become more apparent from the following detailed description of preferred embodiments, along with the accompanying drawing figures in which like numerals represent like components.

[0021] It is to be understood that the aspects and embodiments of the disclosure described above may be used in any combination with each other. Several of the aspects and embodiments may be combined to form a further embodiment of the disclosure.

[0022] The foregoing summary is illustrative only and is not intended to be in any way limiting. In addition to the illustrative aspects, embodiments, and features described above, further aspects, embodiments, and features will become apparent by reference to the drawings and the following detailed description.

BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS
[0023] The illustrated embodiments of the subject matter will be best understood by reference to the drawings, wherein like parts are designated by like numerals throughout. The following description is intended only by way of example, and simply illustrates certain selected embodiments of devices, systems, and processes that are consistent with the subject matter as claimed herein, wherein:-

Figure 1 shows: Schematic diagram of Magnetic Particle Inspection (MPI) testing machine according to the present invention.
Figure 2 shows: Magnetic clamp with cross sectional view in accordance with the invention.
Figure 3(a) shows: Representation of ‘C’ Clamping method of prior art.
Figure 3(b) shows: Representation of new magnetic clamping method of invention.

[0024] The figures depict embodiments of the disclosure for purposes of illustration only. One skilled in the art will readily recognize from the following description that alternative embodiments of the structures and methods illustrated herein may be employed without departing from the principles of the disclosure described herein.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENT(S) OF THE INVENTION WITH REFERENCE TO THE ACCOMPANYING DRAWINGS

[0025] While the embodiments of the disclosure are subject to various modifications and alternative forms, specific embodiment thereof have been shown by way of example in the figures and will be described below. It should be understood, however, that it is not intended to limit the disclosure to the particular forms disclosed, but on the contrary, the disclosure is to cover all modifications, equivalents, and alternative falling within the scope of the disclosure.

[0026] The instant invention makes a disclosure regarding a technology pertaining to an invention directing to Magnetic clamp with Magnetic Particle Inspection (MPI) testing machine for identifying surface and sub-surface imperfections in valves for high pressure boilers and Oil Field Equipments.

[0027] Now, reference may be made to Figure 2, wherein the Magnetic clamp making use of method for Magnetic Clamping Mechanism for MPI testing in Valve Bod comprises of the following parts:

[0028] Magnet (a): This is a material capable of attracting iron objects. This is attracted to the valve body thereby enabling the copper bar/Plate (d) to pass the high current in them.

[0029] Aluminium Casting (b): This is a non-ferrous material used as a casing for the magnet(a) to prevent the magnetic field passing to other areas other than the valve body contact surface.

[0030] Hylem Sheet (c): This is an electrical insulation material used in between the aluminium casting (b) and copper bar/Plate (d) thereby helping to allow current pass only to the valve body surface.

[0031] Copper Bar (d): This is a high current carrying conductor bar which is placed between copper mesh(e) to establish connection between valve body and ports thereby allowing high current to pass to test valve body surface.

[0032] Copper Mesh (e): This is a conducting mesh surrounding the copper bar/Plate (d) to prevent high current arc jumping to valve testing body.

[0033] Referring to figure 1, the power source unit for MPI equipment primarily comprises of a dry type step-down transformer (TR1) (415V/20V & 160KVA). The secondary of the transformer(TR1) is connected to the output ports either directly or through the full wave bridge rectifier assembly by charging or discharging the pneumatic cylinders (11 & 15). By this, the MPI equipment is capable of delivering either AC or FWDC current output for MPI inspection testing. At normal state of the cylinders (11 & 15) the FWDC current output will be connected to the output ports and when the cylinders (11 & 15) are charged the AC current output will be connected to the output ports.

[0034] The connector plate (17) connected to the piston shaft of cylinder (15) is connected to the copper bus bar (4). From the bus bar, the bunch of flexible cables are made to the copper mesh plates fitted on the piston shaft of cylinders. When any the cylinder is charged the piston shaft of that cylinder will provide high current output to that particular output ports (Port-1, Port-2, Port-3 and common port).

[0035] In an exemplary embodiment, two Magnetic Clamps are used and will be connected to Port-1 and common as shown in figure-3 which is more convenient compared to existing ‘C’ type clamps of known art.

[0036] By using this magnetic clamping method, the problems and the time taken for Magnetic Particle Inspection (MPI) testing of valve body are reduced.

[0037] The novel Method for Magnetic Clamping Mechanism for MPI testing in Valve Body provides an easy way for the operator to clamp for testing in the valve body. By this the actual time consumption for MPI test of a typical valve body is reduced from 15minutes to 5minutes (i.e. 63% time is saved). Also the unsafe method of physical handling for clamping during MPI test is avoided.

ADVANTAGES OF INVENTION
-Eliminates the drawbacks of the old C- clamp method for the MPI inspection of the valve bodies,
-Quickest mode of clamping with ease,
-Avoids unsafe method of physical handling for clamping during Magnetic Particle Inspection (MPI) test,
-Provides an easy way for the operator to clamp for testing in the valve body,
-Reduction in actual time consumption for Magnetic Particle Inspection (MPI)test of a typical valve body.
Clamping can be done at any portion of item irrespective of size of item being inspected unlike traditional manual clamping can be done only on portions where flanges and end hollow portions
WORKING OF INVENTION
The clamping is done using the magnetic power associated with magnets to clutch on the object under inspection from two potions of job, as two terminal for passing current. The magnetic power of magnets used is sufficient to handle weight of cables connected to the magnetic end. Also the power of magnet is sufficient to hold on to the job during inspection and when current is passed through it to distribute the current supply on job in the intended direction. Also the copper mesh added to the end could avoid the undue current arc which may strike on start of suppling current for inspection. No repulsion of magnet is noticed during supply of power and are positioned in a way that two clamps (two terminal) on the job attract each other. As a result required clamping is achieved without any screwing and tightening mechanism that was required in traditional way of ‘C” clamping.
TEST RESULT
The clamping with magnetic clutching / clamping is easier way than traditional method as there are no screwing and tightening involved for every clamping and de-clamping activities, which are very heavy when handled in complete manually. This new method of invention is adding its magnetic power to clutch immediately on the job and also provides required force and area required for clamping very easily. The force generated is highly sufficient enough to hold on to the job during entire inspection. The de-clamping is also very easier by operating lever to de-clutch magnetic clamp rather than holding the cable weight and unscrewing clamp by spanner in traditional way.
Required results are achieved with lesser force to handle, ease to clamp and quickest way of clamping and de-clamping, that too at any portion of the job without looking for projected portions to do manual clamping. The results are highly satisfactory.

[0038] Each of the appended claims defines a separate invention, which for infringement purposes is recognized as including equivalents to the various elements or limitations specified in the claims. Depending on the context, all references below to the "invention" may in some cases refer to certain specific embodiments only. In other cases, it will be recognized that references to the "invention" will refer to subject matter recited in one or more, but not necessarily all, of the claims.

[0039] Groupings of alternative elements or embodiments of the invention disclosed herein are not to be construed as limitations. Each group member can be referred to and claimed individually or in any combination with other members of the group or other elements found herein. One or more members of a group can be included in, or deleted from, a group for reasons of convenience and/or patentability. When any such inclusion or deletion occurs, the specification is herein deemed to contain the group as modified thus fulfilling the written description of all groups used in the appended claims.

[0040] It will be understood by those within the art that, in general, terms used herein, and especially in the appended claims (e.g., bodies of the appended claims) are generally intended as “open” terms (e.g., the term “including” should be interpreted as “including but not limited to,” the term “having” should be interpreted as “having at least,” the term “includes” should be interpreted as “includes but is not limited to,” etc.). It will be further understood by those within the art that if a specific number of an introduced claim recitation is intended, such an intent will be explicitly recited in the claim, and in the absence of such recitation no such intent is present. For example, as an aid to understanding, the following appended claims may contain usage of the introductory phrases “at least one” and “one or more” to introduce claim recitations. However, the use of such phrases should not be construed to imply that the introduction of a claim recitation by the indefinite articles “a” or “an” limits any particulars claim containing such introduced claim recitation to inventions containing only one such recitation, even when the same claim includes the introductory phrases “one or more” or “at least one” and indefinite articles such as “a” or “an” (e.g., “a” and/or “an” should typically be interpreted to mean “at least one” or “one or more”); the same holds true for the use of definite articles used to introduce claim recitations. In addition, even if a specific number of an introduced claim recitation is explicitly recited, those skilled in the art will recognize that such recitation should typically be interpreted to mean at least the recited number (e.g., the bare recitation of “two recitations,” without other modifiers, typically means at least two recitations, or two or more recitations). Furthermore, in those instances where a convention analogues to “at least one of A, B and C, etc.” is used, in general such a construction is intended in the sense one having skill in the art would understand the convention (e.g., “a system having at least one of A, B and C” would include but not be limited to systems that have A alone, B alone, C alone, A and B together, A and C together, B and C together, and/or A, B, and C together, etc.). In those instances where a convention analogous to “at least one of A, B, or C, etc.” is used, in general such a construction is intended in the sense one having skill in the art would understand the convention (e.g., “a system having at least one of A, B, or C” would include but not be limited to systems that have A alone, B alone, C alone, A and B together, A and C together, B and C together, and/or A, B, and C together, etc.). It will be further understood by those within the art that virtually any disjunctive word and/or phrase presenting two or more alternative terms, whether in the description, claims, or drawings, should be understood to contemplate the possibilities of including one of the terms, either of the terms, or both terms. For example, the phrase “A or B” will be understood to include the possibilities of “A” or “B” or “A and B”.

[0041] The above description does not provide specific details of manufacture or design of the various components. Those of skill in the art are familiar with such details, and unless departures from those techniques are set out, techniques, known, related art or later developed designs and materials should be employed. Those in the art are capable of choosing suitable manufacturing and design details.

[0042] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the present disclosure. It will be appreciated that several of the above-disclosed and other features and functions, or alternatives thereof, may be combined into other systems or applications. Various presently unforeseen or unanticipated alternatives, modifications, variations, or improvements therein may subsequently be made by those skilled in the art without departing from the scope of the present disclosure as encompassed by the following claims.

[0043] The claims, as originally presented and as they may be amended, encompass variations, alternatives, modifications, improvements, equivalents, and substantial equivalents of the embodiments and teachings disclosed herein, including those that are presently unforeseen or unappreciated, and that, for example, may arise from applicants/patentees and others.

[0044] While various aspects and embodiments have been disclosed herein, other aspects and embodiments will be apparent to those skilled in the art. The various aspects and embodiments disclosed herein are for purposes of illustration and are not intended to be limiting, with the true scope and spirit being indicated by the following claims.
, Claims:We Claim
1. Magnetic clamp with MPI testing machine for identifying surface and sub-surface cracks in valve for high pressure boilers comprises of:
Magnet (a) attached to a valve body thereby enabling a copper bar/Plate (d) to pass the high current there through,
Aluminium Casting (b) constituting a casing for the magnet(a) to prevent the magnetic field passing to areas other than the valve body contact surface,
Hylem Sheet (c) provided in between the Aluminium casting (b) and copper bar/Plate (d) thereby helping to allow current pass to the valve body surface,
Copper Bar/Plate (d) placed between copper mesh(e) to establish connection between said valve body and ports thereby allowing high current to pass to test valve body surface and
Copper Mesh (e) surrounding the copper bar/Plate (d) to prevent high current arc jumping to valve testing body.
2. The Magnetic clamp as claimed in claim 1, wherein the clamp is provided with power source unit for MPI equipment comprising of a dry type step-down transformer (TR1) (415V/20V & 160KVA), in which the secondary of the transformer(TR1) is connected to the output ports directly, alternatively through the full wave bridge rectifier assembly by charging/discharging the pneumatic cylinders (11 & 15).
3. The Magnetic clamp as claimed in claim 1 or 2, wherein the MPI equipment delivers AC/ FWDC current output for MPI inspection testing, in which at normal state of the cylinders (11 & 15) the FWDC current output is connected to the output ports and when the cylinders (11 & 15) are charged, the AC current output is connected to the output ports.
4. The Magnetic clamp as claimed in claim 3, wherein the connector plate (17) connected to the piston shaft of cylinder 15 is attached to the copper bus bar (4).
5. The Magnetic clamp as claimed in claims 1-4, wherein from the bus bar, bunch of flexible cables are made to the copper mesh plates fitted on the piston shaft of cylinders, when any cylinder is charged the piston shaft of that cylinder provides high current output to that particular output ports (Port-1, Port-2, Port-3 and common port).