Patent Publication Number: US-2022236233-A1

Title: Ultrasonic phased array detection device

Description:
TECHNICAL FIELD 
     The present invention generally relates to an ultrasonic phased array detection device for performing flaw detection testing based on an ultrasonic phased array method on equipment provided with a number of tubes. 
     BACKGROUND ART 
     Heat exchangers, reactors and the like in various plants include a number of tubes arranged in parallel with each other at a fixed spacing and a tube-sheet orthogonal to the tubes, which are welded together. Since there are a large number of tubes to be inspected in such heat exchangers and reactors, it is required to inspect each and every tube rapidly and accurately. 
     For example, as an ultrasonic phased array detection device for welds in a number of tubes, Japanese Patent Laid-Open No. 2016-191571 (Patent Literature 1) discloses a device that facilitates adjustment and positioning of an insertion depth into a tube. In the ultrasonic phased array detection device described in Patent Literature 1, a jig to be inserted and fixed in a tube includes an expansion and contraction part that is made larger/smaller than an inside diameter of the tube. Expanding/contracting the expansion and contraction part in the tube makes it easy to fix/release the jig to the tube. 
     SUMMARY OF INVENTION 
     Technical Problem 
     However, the ultrasonic phased array detection device described in the above-mentioned Patent Literature 1 is a dedicated device for tubes that have such a specific inside diameter. Accordingly, the ultrasonic phased array detection device is less accurate in the flaw detection testing on a tube having the inside diameter that is out of the specific inside diameter. Even with tubes that have a specific inside diameter, the ultrasonic phased array detection device is less accurate in the flaw detection testing when the tubes have a non-uniform inside diameter due to reduction in a wall thickness caused by, for example, corrosion. 
     An object of the present invention is to provide an ultrasonic phased array detection device capable of performing flaw detection testing accurately even on tubes with varying inside diameters. 
     Solution to Problem 
     To solve the problem, an ultrasonic phased array detection device according to a first aspect is an ultrasonic phased array detection device for performing flaw detection testing on a welded joint sequentially for a plurality of tubes arranged in parallel with an ultrasonic phased array method, the ultrasonic phased array detection device including: 
     a flaw detection testing unit to be inserted into a target tube and used to perform the flaw detection testing on a welded joint of the target tube, the target tube being subjected to the flaw detection testing among the tubes; 
     a drive mechanism configured to rotate the flaw detection testing unit around an axis of the target tube; and 
     a jig to be inserted and fixed in a tube different from the target tube, 
     wherein the flaw detection testing unit includes: 
     a flaw detection part incorporating a phased array probe used to perform the ultrasonic phased array method; and 
     at least one pressing mechanism configured to press the flaw detection part against an inner surface of the target tube. 
     An ultrasonic phased array detection device according to a second aspect, wherein the ultrasonic phased array detection device according to the first aspect, more than one pressing mechanism of the flaw detection testing unit are disposed on a distal side and a proximal side of the target tube with respect to the flaw detection part. 
     An ultrasonic phased array detection device according to a third aspect, wherein the ultrasonic phased array detection device according to the first or second aspect, the pressing mechanism of the flaw detection testing unit includes: 
     a pressing motive power part capable of moving the flaw detection part toward the inner surface of the target tube by an elastic force; and 
     a guide member for guiding the flaw detection part to the inner surface of the target tube. 
     An ultrasonic phased array detection device according to a fourth aspect, wherein the ultrasonic phased array detection device according to any one of the first to third aspects, it includes an eccentricity accommodating joint connecting the drive mechanism with the flaw detection testing unit while accommodating offset between axial centers of the drive mechanism and the flaw detection testing unit. 
     An ultrasonic phased array detection device according to a fifth aspect, wherein the ultrasonic phased array detection device according to any one of the first to fourth aspects, 
     it includes a body for holding the jig and the flaw detection testing unit, and 
     the body includes an adjuster for adjusting depth of the flaw detection part in the target tube. 
     Advantageous Effects of Invention 
     According to the ultrasonic phased array detection device, it is possible to perform flaw detection testing accurately even when the inside diameter varies due to, for example, reduction in a wall thickness caused by corrosion on the target tube because the phased array probe and the inner surface of the target tube can be kept in contact with each other while performing the flaw detection testing. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         FIG. 1  is a schematic perspective view illustrating an ultrasonic phased array detection device according to Embodiment 1 of the present invention before it is fixed in a tube. 
         FIG. 2  is a schematic sectional view illustrating the ultrasonic phased array detection device while it is fixed in the tube. 
         FIG. 3  is a schematic sectional view illustrating a variation of the ultrasonic phased array detection device. 
         FIG. 4  is a schematic sectional view illustrating an ultrasonic phased array detection device according to Embodiment 2 of the present invention while it is fixed in a tube. 
         FIG. 5  is a schematic sectional view illustrating a variation of the ultrasonic phased array detection device. 
         FIG. 6  is a perspective view illustrating an ultrasonic phased array detection device according to Example of the present invention before it is fixed in a tube. 
         FIG. 7  is a sectional view illustrating the ultrasonic phased array detection device before it is fixed in the tube. 
         FIG. 8  is a front view illustrating the ultrasonic phased array detection device before it is fixed in the tube. 
         FIG. 9  is a sectional view illustrating the ultrasonic phased array detection device while it is fixed in the tube. 
     
    
    
     DESCRIPTION OF EMBODIMENTS 
     Embodiment 1 
     The ultrasonic phased array detection device according to embodiments of the present invention will now be described with reference to drawings. 
     As illustrated in  FIG. 1 , for equipment including a number of tubes  9  arranged in parallel (in a row) with each other at a fixed spacing and a tube-sheet  91  orthogonal to the tubes  9 , which are welded together, an ultrasonic phased array detection device  1  is an inspection device for performing flaw detection testing on welded portions (hereinafter referred to as welded joints  92 ) with an ultrasonic phased array method sequentially (one by one) from inside the tubes  9 . Hereinafter, among a number of tubes  9  described above, a tube  94  under flaw detection testing or a tube  94  to be subjected to the flaw detection testing will be considered as a tube  94  targeted for the flaw detection testing and will be referred to as a target tube  94 . When a specific tube  9  is to be subjected to flaw detection testing, the specific tube  9  is the target tube  94 . However, once the flaw detection testing is completed, the specific tube  9  becomes unfit for the target tube  94 , and a next tube  9  to be subjected to the flaw detection testing will be the target tube  94 . 
     As illustrated in  FIGS. 1 and 2 , the ultrasonic phased array detection device  1  includes a flaw detection testing unit  4  to be inserted into the target tube  94  and used to perform flaw detection testing on the welded joint  92  of the target tube  94 , a drive mechanism  2  configured to rotate the flaw detection testing unit  4  around an axis  90  of the target tube  94 , and a jig  6  to be inserted and fixed in a tube  96  different from the target tube  94 . The flaw detection testing unit  4  includes a flaw detection part  41  incorporating a phased array probe  42  used to perform the ultrasonic phased array method, and at least one pressing mechanism  45  configured to press the flaw detection part  41  against an inner surface of the target tube  94 . 
     The flaw detection testing unit  4  is not necessarily inserted in its entirety into the target tube  94 , but rather the flaw detection part  41  may be inserted into the target tube  94  down to at least a depth at which the flaw detection testing on the welded joint  92  can be performed from inside the target tube  94 . Hereinafter, a destination side to which the flaw detection testing unit  4  is inserted and an entry side from which the flaw detection testing unit  4  is inserted in the target tube  94  are referred to as a distal side and a proximal side of the target tube  94 , respectively. 
     The pressing mechanism  45  is not particularly limited if the flaw detection part  41  is caused to be pressed against the inner surface of the target tube  94 , and is, for example, any pressing component by means of an elastic force (elastic member) such as a compression spring  46 , a tension spring, or a brush, any pressing component by means of a magnetic force, or any pressing component by means of an air pressure or a hydraulic pressure. In a case in which the pressing mechanism  45  is to be brought into contact with the inner surface of the target tube  94 , the pressing mechanism  45  preferably includes a roller  48  at a portion contacting the inner surface. This is because such a roller  48  reduces friction between the pressing mechanism  45  and the inner surface of the target tube  94 . In addition, setting of the pressing mechanism  45  is made to such an extent that a pressing force thereof does not impede the flaw detection testing unit  4  from being rotated by the drive mechanism  2  (does not reduce rotating speed significantly). As illustrated in  FIG. 3 , the pressing mechanism  45  may include a pressing motive power part (for example, an elastic member such as a compression spring  46  or a brush) provided between a longitudinal member  40  and the flaw detection part  41  that constitute the flaw detection testing unit  4 , and a guide member  49  for guiding the flaw detection part  41  to the inner surface of the target tube  94 . Preferably, the guide member  49  guides the flaw detection part  41  to the inner surface of the target tube  94  in an orthogonal manner. 
     The drive mechanism  2  is not particularly limited if the flaw detection testing unit  4  is caused to rotate around the axis  90  of the target tube  94 , and is, for example, a motor. 
     The jig  6  is not particularly limited if it is fixed in the tube  96  while it is inserted in the tube  96  different from the target tube  94 , and may be, for example, a leg part including, on an outermost end thereof, an inflatable part that is inflatable and shrinkable within the tube  96 , or a leg part including, on an outermost end thereof, an expansion and contraction part that can be expanded and contracted mechanically within the tube  96 . 
     Usage of the ultrasonic phased array detection device  1  will now be described. 
     First, as illustrated in  FIG. 1 , the flaw detection testing unit  4  is inserted into the target tube  94  while the jig  6  is inserted into the tube  96  different from the target tube  94  and the jig  6  is fixed in the tube  96 . Then, as illustrated in  FIG. 2 , the flaw detection part is pressed against the inner surface of the target tube  94  within the target tube  94  by the pressing mechanism  45 . 
     Next, the flaw detection testing unit  4  is rotated around the axis  90  of the target tube  94  by the drive mechanism  2 . While rotating, the flaw detection testing unit  4  performs the flaw detection testing with ultrasonic waves from the phased array probe  42  with the phased array method. At this time, the phased array probe  42  and the inner surface of the target tube  94  are kept in contact with each other because the flaw detection part  41  is pressed against the inner surface of the target tube  94  by the pressing mechanism  45 . 
     In this way, according to the ultrasonic phased array detection device  1 , it is possible to perform flaw detection testing accurately even when the inside diameter varies due to, for example, reduction in a wall thickness caused by corrosion on the target tube  94  because the phased array probe  42  and the inner surface of the target tube  94  are kept in contact with each other while performing the flaw detection testing. 
     Embodiment 2 
     An ultrasonic phased array detection device  1  according to Embodiment 2 capable of performing flaw detection testing more accurately than the ultrasonic phased array detection device  1  according to Embodiment 1 will now be described with reference to drawings. In Embodiment 2, configurations different from those of Embodiment 1 are focused, and the same configurations as those of Embodiment 1 will be given the same reference characters and description thereof will not be repeated. 
     As illustrated in  FIG. 4 , the ultrasonic phased array detection device  1  according to Embodiment 2 includes a body  5  for holding a jig  6  and a flaw detection testing unit  4 . 
     A drive mechanism  2  includes an electric motor  21  fixed to the body  5 , a pinion  22  connected to an output shaft of the electric motor  21 , and a gear  23  that meshes with the pinion  22 . 
     The ultrasonic phased array detection device  1  includes an eccentricity accommodating joint  3  connecting the drive mechanism  2  with the flaw detection testing unit  4 . The eccentricity accommodating joint  3  accommodates offset between an axial center of the drive mechanism  2  (hereinafter referred to as a driving axial center  31 ) and an axial center of the flaw detection testing unit  4  (hereinafter referred to as a driven axial center  32 ). The eccentricity accommodating joint  3  may be one that transfers rotation of the drive mechanism  2  around the driving axial center  31  into rotation of the flaw detection testing unit  4  around the driven axial center  32  (transfers into rotation), or may be one that transfers rotation of the drive mechanism  2  around the driving axial center  31  into rotation of the flaw detection testing unit  4  around the driving axial center  31  (transfers into revolution). 
     The body  5  includes an adjuster  7  for adjusting depth of a flaw detection part  41  in a target tube  94 . The adjuster  7  is a bolt  72  provided with a tab  71  on one end, and threaded into an internally threaded hole  57  formed in the body  5  along the driving axial center  31 , the one end being located outside the body  5  and the other side being connected to the gear  23  within the body  5  with a bearing  24  or the like in between. 
     For example, there are more than one pressing mechanism  45  of the flaw detection testing unit  4 ;  FIG. 4  illustrates a case of two pressing mechanisms. One of the pressing mechanisms  45  is disposed on the distal side of the target tube  94  and the other is disposed on the proximal side of the target tube  94 . In other words, the pressing mechanisms  45  are disposed on the distal and proximal sides of the target tube  94  with respect to the flaw detection part  41 . The one of the pressing mechanisms  45  disposed on the proximal side of the target tube  94  may be located within the target tube  94  as illustrated in  FIG. 4  or may be located within the body  5  as illustrated in  FIG. 5 . The configuration illustrated in  FIG. 4  is suitable for flaw detection testing when the welded joint  92  is located further on the distal side of the target tube  94 , and the configuration illustrated in  FIG. 5  is suitable for flaw detection testing when the welded joint  92  is located further on the proximal side of the target tube  94 . 
     Usage of the ultrasonic phased array detection device  1  will now be described. 
     First, as illustrated in  FIGS. 4 and 5 , the flaw detection testing unit  4  is inserted into the target tube  94  while the jig  6  is inserted into a tube  96  different from the target tube  94  and the jig  6  is fixed in the tube  96 . Then, the flaw detection part  41  is pressed against an inner surface of the target tube  94  within the target tube  94  by the pressing mechanisms  45 . The pressing is achieved from both the distal and proximal sides of the target tube  94  with respect to the flaw detection part  41 , providing higher stability than Embodiment 1. 
     After the jig  6  is fixed in the tube  96  different from the target tube  94 , it may in some cases be found that the depth of the flaw detection part  41  in the target tube  94  is not appropriate. In this case, turning the tab  71  of the adjuster  7  allows adjustment of the depth. 
     Next, the flaw detection testing unit  4  is rotated around an axis  90  of the target tube  94  by the drive mechanism  2 . At this time, depending on the inside diameter of the target tube  94 , it is necessary to offset the driving axial center  31 , which is the axial center of the drive mechanism  2 , and the driven axial center  32 , which is the axial center of the flaw detection testing unit  4 . However, the offset is accommodated by the eccentricity accommodating joint  3 , so that rotation is appropriately transferred from the drive mechanism  2  to the flaw detection testing unit  4 . Then, while rotating, the flaw detection testing unit  4  performs the flaw detection testing with ultrasonic waves from a phased array probe  42  with a phased array method. At this time, the phased array probe  42  and the inner surface of the target tube  94  are kept in contact with each other because the flaw detection part  41  is pressed against the inner surface of the target tube  94  by the pressing mechanisms  45 . 
     In this way, according to the ultrasonic phased array detection device  1 , it is possible to perform flaw detection testing more accurately even when the inside diameter varies due to, for example, reduction in a wall thickness caused by corrosion on the target tube  94  because the phased array probe  42  and the inner surface of the target tube  94  are stably kept in contact with each other while performing the flaw detection testing. 
     Additionally, since the offset between the axial centers  31  and  32  of the drive mechanism  2  and the flaw detection testing unit  4  is accommodated by the eccentricity accommodating joint  3 , the flaw detection testing unit  4  rotates appropriately with respect to the target tube  94 . As a result, it is possible to perform flaw detection testing more accurately. 
     Further, the depth of the flaw detection part  41  in the target tube  94  is adjusted by the adjuster  7 , positional relationship between the welded joint  92  of the target tube  94  and the flaw detection part  41  is made more appropriate. As a result, it is possible to perform flaw detection testing more accurately. 
     EXAMPLE 
     An ultrasonic phased array detection device  1  according to Example, which illustrates Embodiments 1 and 2 more specifically, will now be described with reference to  FIGS. 6 to 9 . In Example, configurations different from those of Embodiments 1 and 2 are focused, and the same configurations as those of the embodiments will be given the same reference characters and description thereof will not be repeated. 
     As illustrated in  FIGS. 6 and 7 , a body  5  of the ultrasonic phased array detection device  1  according to Example has a bifurcated shape with two generally cuboids and  53  connected at outermost ends thereof. Hereinafter, one of the two generally cuboids  52  and  53  that has a protruded flaw detection testing unit  4  will be referred to as a testing unit-side cuboid  53 , the other cuboid will be referred to as a motor-side cuboid  52 , and a portion that connects the testing unit-side cuboid  53  with the motor-side cuboid  52  at outermost ends thereof will be referred to as a connecting part  55 . 
     As illustrated in  FIGS. 6 and 8 , a jig  6  of the ultrasonic phased array detection device  1  according to Example includes an elongated hole holding member  65  attached to the testing unit-side cuboid  53  in an orientation orthogonal to a driving axial center  31 , two leg parts  61  that are arranged in parallel to the flaw detection testing unit  4  and fixed at any position in the elongated hole holding member  65 , an inflatable part  62  that is provided to each of the two leg parts  61  at the outermost ends thereof and is inflatable and shrinkable, and an air tube  63  that supplies and discharges air for inflating and shrinking the inflatable part  62 . The leg parts  61  are each adjustable in length thereof and can be fastened at any position in an elongated hole formed in the elongated hole holding member  65 . When inserted in each of two tubes  96  adjacent to a target tube  94 , each of the leg parts  61  is fixed to the elongated hole holding member  65  at a position where the flaw detection testing unit  4  is inserted into the target tube  94 . 
     Next, description will be made as to a state in which the jig  6  of the ultrasonic phased array detection device  1  is inserted and fixed in the tubes  96  adjacent to the target tube  94  with reference to  FIG. 9 . 
     An electric motor  21  is contained in the motor-side cuboid  52  and fixed to the motor-side cuboid  52 . A pinion  22 , which is connected to an output shaft of the electric motor  21 , is contained in an outermost end portion of the motor-side cuboid  52 . A gear  23  that meshes with the pinion  22  is contained through the connecting part  55  and an outermost end portion of the testing unit-side cuboid  53 . A bearing  24  for the gear  23  is contained in the outermost end portion of the testing unit-side cuboid  53  and can be moved along the driving axial center  31  by an adjuster  7 . An internally threaded hole  57  into which a bolt  72  of the adjuster  7  is threaded is formed on an extension of the driving axial center  31  in the testing unit-side cuboid  53 . 
     An eccentricity accommodating joint  3  connected to the gear  23  is contained in the testing unit-side cuboid and includes members  33  to  36  as described below. Specifically, the eccentricity accommodating joint  3  includes a flexible coupling  33  to which a shaft of the gear  23  is connected on a driving side, a driven member  34  connected to the flexible coupling  33  on a driven side, a guide pin  35  that is attached to the driven member  34  and is orthogonal to the driving axial center  31 , and a sliding member  36  that slides along the guide pin  35 . The flexible coupling  33  transfers rotation of the gear  23  around the driving axial center  31  into rotation and the driven member  34 , the guide pin  35 , and the sliding member  36  transfers the rotation of the gear  23  around the driving axial center  31  into revolution. 
     The flaw detection testing unit  4  includes a longitudinal member  40  along a driven axial center  32 , pressing mechanisms  45  that press the longitudinal member  40  in a direction parallel to the guide pin  35 , and a flaw detection part  41  provided on the longitudinal member  40 . The longitudinal member  40  is attached to the sliding member  36  on one end within the testing unit-side cuboid  53 , and a center portion and the other end protrude from the testing unit-side cuboid  53 . The pressing mechanisms  45  are disposed inside and outside the testing unit-side cuboid  53 , respectively. Each pressing mechanism  45  includes compression springs  46  connected to the longitudinal member  40  on one end and a roller member  47  connected to the other end of the compression springs  46 . The roller member  47  includes rollers  48  that rotates around an axial center parallel to the driven axial center  32 . The flaw detection part  41  includes a phased array probe  42  disposed near a surface of the longitudinal member  40 , a wedge  43  that covers the phased array probe  42  and is allowed to face an inner surface of the target tube  94 , and media supplying holes from which contact media required for flaw detection testing can be supplied from around the wedge  43 . 
     Usage of the ultrasonic phased array detection device  1  will now be described. 
     First, as illustrated in  FIG. 6 , the flaw detection testing unit  4  is inserted into the target tube  94  while the shrunk inflatable parts  62  of the jig  6  are inserted into the tubes  96  adjacent to the target tube  94 . Next, as illustrated in  FIG. 9 , the inflatable parts  62  are caused to inflate within the tubes  96  to fix the jig  6  in the tubes  96 . Then, the flaw detection part  41  is pressed against the inner surface of the target tube  94  within the target tube  94  by the pressing mechanisms  45 . 
     After the jig  6  is fixed in the tubes  96  adjacent to the target tube  94 , it may in some cases be found that the depth of the flaw detection part  41  in the target tube  94  is not appropriate. For example, it is often the case that a monitor (not illustrated) electrically connected to the flaw detection part  41  is used to verify a status of the flaw detection testing. In this case, turning a tab  71  of the adjuster  7  allows adjustment of the depth. 
     Next, the flaw detection testing unit  4  is rotated around an axis  90  of the target tube  94  by a drive mechanism  2 . At this time, depending on the inside diameter of the target tube  94 , it is necessary to offset the driving axial center  31 , which is an axial center of the drive mechanism  2 , and the driven axial center  32 , which is an axial center of the flaw detection testing unit  4 . However, the offset is accommodated by the eccentricity accommodating joint  3 , so that rotation is appropriately transferred from the drive mechanism  2  to the flaw detection testing unit  4 . In particular, since the eccentricity accommodating joint  3  transfers rotation of the drive mechanism  2  into rotation and revolution, the rotation is transferred appropriately from the drive mechanism  2  to the flaw detection testing unit  4  even when the offset is large. Then, while rotating, the flaw detection testing unit  4  performs the flaw detection testing with ultrasonic waves from the phased array probe  42  with the phased array method. At this time, the phased array probe  42  and the inner surface of the target tube  94  are kept in contact with each other because the flaw detection part  41  is pressed against the inner surface of the target tube  94  by the pressing mechanisms  45 . A spacing of several to several hundreds of micrometres is created between the inner surface of the target tube  94  and the wedge  43 ; the spacing is to be filled with contact media supplied from the media supplying holes  44  by capillary action. Then, the flaw detection testing is achieved more appropriately. 
     In this way, according to the ultrasonic phased array detection device  1 , advantageous effects described below are produced in addition to effects produced in Embodiments 1 and 2. Specifically, since the offset between the axial centers  31  and  32  is accommodated more appropriately by the eccentricity accommodating joint  3  that transfers rotation of the drive mechanism  2  into rotation and revolution, the flaw detection testing unit rotates more appropriately with respect to the target tube  94 . As a result, it is possible to perform flaw detection testing far more accurately. 
     In Embodiments 1 and 2 and Example, although the equipment in which the tubes  9  protrude from the tube-sheet  91  on the proximal side is illustrated for the detention testing, an equipment in which the tubes  9  do not protrude from the tube-sheet  91  on the proximal side may be used for the detention testing. 
     Further, in Embodiment 2 and Example, the same pressing mechanisms  45  are illustrated as being disposed on the distal and proximal sides of the target tube  94  with respect to the flaw detection part  41 , the pressing mechanisms  45  may be different from each other. Preferably, the pressing mechanisms  45  press the flaw detection part  41  against the inner surface of the target tube  94  uniformly in a depth direction. This is because when the flaw detection part  41  is pressed uniformly in the depth direction, it is possible to perform flaw detection testing far more accurately. In a case in which the pressing mechanism  45  is disposed within the testing unit-side cuboid  53 , even when the elastic member of the pressing mechanism  45  is a tension spring, the flaw detection part  41  is pulled toward the inner surface of the target tube  94  by the tension spring via the longitudinal member  40 , so that the flaw detection part  41  can be pressed against the inner surface of the target tube  94 . 
     In Embodiments 1 and 2 and Example, although description has been made as to a case in which the number of pressing mechanisms  45  is 1 or 2, it may be 3 or more. In a case in which the pressing mechanism  45  can be reduced in size, it is preferable that the pressing mechanism  45  does not press the inner surface of the target tube  94  as illustrated in  FIG. 3 . The pressing motive power part illustrated as being the compression spring  46  in  FIG. 3  may not be limited to an elastic member such as the compression spring  46  if the flaw detection part  41  can be moved toward the inner surface of the target tube  94  in any way. 
     Embodiments 1 and 2 and Example described above are illustrative only in all respects and are not limitation. The scope of the present invention is to be defined not by the above description but by claims, and is intended to encompass all modifications within the sense and scope equivalent to claims. Except the configuration described as the first aspect in “Solution to Problem”, any other configurations described in Embodiments 1 and 2 and Example are optional and may be omitted or changed as appropriate.