Abstract:
An optic device for use in viewing the interior of pressurized vessels, especially high pressure fluid pipelines. Embodiments of the optic device allow manual or automatic insertion/retraction of the viewing head allowing variable depth viewing of the interior. The viewing head is capable of various embodiments including the ability to carry various optic devices and is adapted to withstand high pressures. The automatically insertable optic device can be either hydraulically or pneumatically actuated. Both the automatic and manual optic devices may be fixed or variable focus. The fixed focus devices utilize lenses, ultra-miniature color cameras, and fiberscopes either with or without integral light sources as part of the viewing head. The variable focus device utilizes lenses and a reflector. Preferably, the viewing head utilizes sapphire viewing windows which exhibit excellent light transmission and resistance to high pressures. In this manner, light may be received for pickup by the lenses, camera, fiberscope, or the like.

Description:
This application, under 37 CFR 1.53(b), is a Division of application Ser. No. 09/030,180, filed Feb. 25, 1998 now U.S. Pat. No. 6,091,489. 
    
    
     BACKGROUND OF THE INVENTION 
     a. Field of the Invention 
     The present invention relates to optical inspection devices and, more particularly, to optical inspection devices for use in pressurized vessels such as pipelines and the like. 
     b. Description of the Prior Art 
     In many instances, it is necessary to view the interior of pressurized vessels such as pipelines and the like in order to ascertain whether there has been any damage to particular parts of the pipeline such as orifice plates, or see if there is a clog or debris buildup which can affect accurate metering and/or flow of the pipeline product. For example, it may be necessary to view the interior of a pipeline metering station to determine if any damage or obstructions affect the orifice metering plate. Of course, such inspection cannot be accomplished without various equipment to enable one to remotely view the interior. Also, in cases where the pipeline product may be explosive, due consideration must be accorded potential hazards. Because of this, the prior art has provided various viewing devices. 
     One such viewing device is disclosed in U.S. Pat. No. 4,777,567 issued to Robert H. Welker et al. on Oct. 11, 1988. The viewing device of the &#39;567 patent utilizes an explosion-proof light projector and viewing periscope particularly for viewing the interior of a gas pipeline metering station. Light from the external light projector is directed into the pipeline through a projector inserted through a bore in the pipeline, while a separate, fixed-depth periscope viewing device extends into the pipeline through a separate bore in the pipeline. The viewing device is not however, adapted for use in high-pressure environments. 
     Another such prior art viewing device is disclosed in U.S. Pat. No. 4,678,290 issued to Robert H. Welker on Jul. 7, 1987. The &#39;290 viewing device is a fixed depth periscope assembly having an optical system including a lamp sealed therein for a light source. A flow of nitrogen gas is delivered to the battery pack for the lamp and periscope to surround the electrical components for explosion prevention. Again, however, the viewing is at a fixed depth, is not insertable and retractable, nor adapted for high pressure environment use. 
     Other prior art devices have been used such as endoscopes that rely upon fiber optic light guides for light transmission. However, these devices are not well suited for use in applications where the object to be examined is relatively far away from the viewing scope such as in pipeline applications. 
     In general, the prior art devices for viewing the interior of vessels including pipelines are not suited for high pressure environments as encountered in active product flowing pipelines, are not insertable or retractable, nor can they retract from their position within the pipeline without being totally removed from the vessel. 
     Furthermore, such prior art designs cannot, by their nature, take advantage of technologically advanced optic devices or viewing options, as such optic devices could be used to view other spectra or provide digitally capturable images, for example. 
     It is thus an object of the present invention to provide a variable depth optic device for viewing the interior of pressurized vessels. 
     It is another object of the present invention to provide an automatically insertable and retractable viewing device for pressurized vessels. 
     It is further an object of the present invention to provide a variable depth optic device for internal viewing of pressurized pipelines that includes an insertable and retractable viewing head adapted to carry various optic devices. 
     It is still further an object of the present invention to provide a viewing device that is insertable into and retractable from a pressurized pipeline and which has a viewing head capable of carrying various optic devices and able to withstand high pipeline pressures. 
     SUMMARY OF THE INVENTION 
     In keeping with the above objects, the present invention is an optic device for viewing the interior of high pressure vessels. 
     In one form thereof, the present optic device includes a viewing head that is axially displaceable within a pressurized pipeline for variable depth viewing. Axial movement of the viewing head may be automatic or manual. In the automatic embodiment, axial movement of the viewing head may be effected by hydraulic or pneumatic means. Viewing may be fixed or variable focus. 
     The viewing head may carry or contain various optic devices such as lenses and reflectors, board cameras, and fiberscopes, while the body of the device is adapted to contain any necessary wires or cables. A viewing aperture is disposed in a wall of the viewing head wherein a transmissive element, preferably sapphire window, is utilized to allow the transmission of light therethrough. 
     In another form, the present optic device is a combination light source and viewer incorporating the features described above. 
     Particularly, in general, a tubular or cylindrical piston carrying the viewing head extends from the piston frame or body and is adapted to axially move relative thereto. In the automatic mode the tubular piston and piston frame define internal variable volume chambers which may be selectively filled and/or evacuated to achieve axial movement. The viewing head contains the optic device for viewing the interior of the pipeline and is constructed to withstand high pipeline pressures, particularly with the use of a sapphire window for the viewing port through which any various type of optic device may peer. Any necessary wires are arranged in the piston frame and extend to the opposite end of the tubular piston. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     So that the manner in which the above recited features, advantages and objects of the present invention are attained and can be understood in detail, a more particular description of the invention briefly summarized above, may be had with reference to the embodiments which are illustrated in the appended drawings, wherein: 
     FIG. 1 is a cross-sectional view of a pipeline metering station with an automatically insertable version of the present optical inspection apparatus disposed therein; 
     FIG. 2 is a cross-sectional view of an embodiment of an automatically insertable optical inspection device having a fixed, passive magnification system; 
     FIG. 3 is an enlarged cross-sectional view of an end of the insertable optical inspection device of FIG. 2 taken along circle  3 — 3  thereof; 
     FIG. 4 is a cross-sectional view of another embodiment of the automatically insertable optical inspection device having an adjustable, passive magnification system; 
     FIG. 5 is an enlarged cross-sectional view of an end of the insertable optical inspection device of FIG. 4 taken along circle  5 — 5  thereof; 
     FIG. 6 is a cross-sectional view of a further embodiment of the automatically insertable optical inspection device having an ultra-miniature color camera system; 
     FIG. 7 is an enlarged cross-sectional view of an end of the insertable optical inspection device of FIG. 6 taken along circle  7 — 7  thereof; 
     FIG. 8 is a cross-sectional view of a yet further embodiment of the automatically insertable optical inspection device having an ultra-miniature color camera and an integral light source; 
     FIG. 9 is an enlarged cross-sectional view of an end of the insertable optical inspection device of FIG. 8 taken along circle  9 — 9  thereof; 
     FIG. 10 is a cross-sectional view of a fixed optical inspection system having an ultra-miniature color camera mounted into a section of pipeline; 
     FIG. 11 is an enlarged cross-sectional view of the optical inspection system of FIG. 10 taken along circle  11 — 11  thereof; 
     FIG. 12 is a bottom view of the optical inspection system of FIG. 10; 
     FIG. 13 is a cross-sectional view of a still another embodiment of the automatically insertable optical inspection device having a side field of view fibrescope type optic system; 
     FIG. 14 is an enlarged cross-sectional view of an end of the insertable optical inspection device of FIG. 13 taken along circle  14 — 14  thereof; 
     FIG. 15 is an enlarged cross-sectional view of the end of the insertable optical inspection device of FIG. 13 fitted with a front field of view fiberscope optic system; 
     FIG. 16 is a perspective view of a side field of view fiberscope; 
     FIG. 17 is a perspective view of a front field of view fiberscope; 
     FIG. 18 is a cross-sectional view of a manually insertable optical inspection device; 
     FIG. 19 is an enlarged cross-sectional view of an end of the manually insertable optical inspection device of FIG. 18 having a passive magnification system; 
     FIG. 20 is an enlarged cross-sectional view of the end of the manually insertable optical inspection device of FIG. 18 having an ultra-miniature color camera system; and 
     FIG. 21 is an enlarged cross-sectional view of the end of the manually insertable optical inspection device of FIG. 18 having a combination ultra-miniature color camera and light source system. 
    
    
     It is to be noted, however, that the appended drawings illustrate only typical embodiments of the invention and are therefore not to be considered limiting of its scope, for the invention may admit to other equally effective embodiments, or combinations of those shown. 
     DETAILED DESCRIPTION OF THE INVENTION 
     Referring to FIG. 1, numeral  1  generally refers to an embodiment of the present optical viewing or inspection device. The optical viewing device  1  may utilize an external light source, such as an explosion-proof light system  2  as depicted. Such explosion-proof light systems may be as those disclosed and discussed in U.S. Pat. No. 4,777,567. Arbitrarily, the optical viewing device  1  is shown in FIG. 1 as the direct-view type, however, other types as disclosed herein may be substituted therefor. Numeral  4  refers generally to a metering station for which the present optical viewing device may be used. The metering station  4  usually extends from the ground (not shown) and is connected to a pipeline inlet  6  and outlet  7 . Isolation from the pipeline is accomplished by valves  8  and  9  associated respectively with the inlet  6  and outlet  7 . 
     The valve  8  connects to a meter tube  10  by a 90 degree fitting  12  providing communication between the pipeline and the metering station  4 . Connection between the meter tube  10  and the 90 degree fitting  12  is effected by a flange  13  formed on one end thereof that corresponds with a flange  14  formed on one end of the meter tube  10  by several bolts  15  extending about the flanges. The pipeline product flows within the metering station  4  as indicated by the arrow. At the downstream end of the meter tube  10  is a spool  16 . The spool  16  has a flange  17  formed on one end thereof that is connected to a flange  18  formed on the end of the meter tube  10  opposite the flange  14  by several bolts  19  extending about the flanges  17 ,  18 . Generally disposed between the flange  18  of the meter tube  10  and the flange  17  of the spool  16  is an orifice plate  20 . The orifice plate  20  has a passageway  21  formed therein and is sized so that the amount of pipeline product passing through the meter station  4  may be calculated according to various charts and tables provided for that purpose. The bolts  19  provide compression between the flanges  17 ,  18  to retain the orifice plate  20 . The spool  16  is connected to and in communication with the valve  9  by another 90 degree fitting  22 . The 90 degree fitting  22  has a flange  23  that connects to a flange  24  on another end of the spool  16  by several bolts  25 . 
     Disposed within an upstream portion of the meter tube  10  are straightening vanes  26  that are designed to produce a laminar flow of pipeline product prior to contact with the orifice plate  20 . Turbulence reduction increases the metering accuracy of the orifice plate  20 . When the valves  8  and  9  are open, the pipeline product enters the metering station  4  via inlet  6 , flows into the meter tube  10 , past the vanes  26  and through the orifice plate opening  21  for measurement, and exits via flow through the spool  16 , fitting  22 , and outlet  7 . Build-ups or deposits  27  may appear near the vanes  26  as a consequence thereof. 
     The meter tube  10  has two fittings  28 ,  29  that define passageways from the exterior of the meter tube  10  and the interior of the meter tube  10 . One end of the viewing device  1  is disposed in the fitting  29 , while the fitting  28  is shown open without a normal bullplug disposed therein. During operation, the fittings  28 ,  29  are plugged in some manner, such as with a bullplug or instrument. The spool  16  likewise has two fittings  30 ,  31  that define passageways from the exterior of the spool  16  and the interior of the spool  16 . One end of the light source  2  is disposed in the fitting  31 , while the fitting  30  is shown open without a normal bullplug disposed therein. Again, during operation, the fittings  30 ,  31  are plugged in some manner, such as with a bullplug or instrument. 
     In applications of some embodiments of the present invention, an external light source needs to be projected into the metering station  4 . For this a light source  2  is shown. Generally, the light source  2  includes an explosive-proof housing  38  that is coupled to a suitable power supply (not shown). An explosive-proof controller  39  controls the lamp  40 . The light from the lamp  40  is projected through the hose  41  and into a housing  36  that extends into the pipe and which projects the light into the pipe, as by a fiberoptic light guide system. 
     Thus, in FIG. 1, a light generated by a light system ( 2 ) is projected into the pipeline while a viewing device ( 1 ) that extends into the pipeline utilizes the projected light to view the interior of the pipeline. One aspect of the present invention lies in the viewing device. 
     Referring now to FIGS. 2 and 3, there is shown a fixed magnification type viewing device  1  having an adjustable depth viewing head. The viewing device  1  includes a cylindrical or tubular body  34  supported between an upper head  46  and a lower head  48 , the heads  46 ,  48  being held together by bolts  47  extending thereabout. The heads  46 ,  48  have O-ringed bores  45 ,  37  respectively, that movably support an elongate piston tube or cylinder  42  which extends therethrough, the tube  42  carrying an inner tube  49 . The inner surface of the body  34  and the outer surface of the tube  42  between the heads  46 ,  48  define a cavity that is divided into a first variable volume  36  and a second variable volume  35  by an O-ringed annular sleeve or ring  52 . The first variable volume  36  is in communication with atmosphere via a conduit  50  in the upper head  46  to which is coupled a valve  51 . The second variable volume  35  is in communication with atmosphere via a conduit  53  in the lower head  48  to which is coupled a valve  54 . In this manner the tube  42  is axially movable via hydraulic or pneumatic pressure through appropriate application to or evacuation from the valves  51  and  54 . Coupled to the upper end of the tube  42  is a conduit piece  44  for viewing and a stop or manual tube positioner  43 . 
     With particular reference to FIG. 3 the viewing head  56  attached to another end of the tube  42  is shown in greater detail. The viewing head  56  in this embodiment includes a holder  58  that is configured to be received in an end  59  of the tube  42 . The holder  58  is secured to the inside of the end  59  via fasteners  62  with an end cap  65  threadedly received on the end  59 . Retained on an end of the holder  58  proximate the conduit piece  44  is an optic lens  60 , here a convex optic lens, for focusing any received light rays axially through the tube  42  towards the conduit piece  44 . The holder  58  also carries a reflector  61  that is angled so as to redirect the light entering through a window  64  threadedly disposed in a bore  63  in the side of the end  59 . The window  64  allows light to enter the inside of the tube  42  to be reflected by the reflector  61  into the lens  60  which focuses the light towards the conduit piece  44 . This configuration has a side field of view. Because the present invention is designed to be used in high pressure environments, the window  64  must be suitable for such use. 
     According to an aspect of the present invention, the window  64  is preferably an HEM™ (Heat Exchange Method) sapphire window manufactured by Crystal Systems of Salem, Mass. Such a sapphire provides outstanding optical and physical properties for the present application and is characterized by good thermal conductivity and low expansion, along with high meltpoint and high strength, permitting use at high temperatures and under high thermal and mechanical shock conditions. Several grades are manufactured. 
     Referring now to FIGS. 4 and 5, there is shown an adjustable magnification viewing device  1 . In this embodiment, a cylindrical body  68  is retained between an upper head  70  and a lower head  71  by several bolts  75 . A tubular piston or cylinder  72  is axially movably supported by the upper and lower heads  70 ,  71  by O-ringed bores  91 ,  93  respectively in the upper and lower heads  70 ,  71 . The inner surface of the body  68  and the outer surface of the tube  72  define a cavity that is divided into a first variable volume  85  and a second variable volume  86  by an O-ringed annular sleeve or ring  84  disposed about the tube  72  between the heads  70 ,  71 . The upper head  70  includes a conduit  87  therein providing communication between a valve  88  (atmosphere) and the second variable volume  86 , while the lower head  71  includes a conduit  89  providing communication between a valve  90  (atmosphere) and the first variable volume  85 . Again, in this manner, the tube  72  is axially movable via selective application or evacuation of hydraulic or pneumatic means (not shown). 
     A viewing head  92  is disposed at one end of the tube  72  that extends beyond the lower head  71  and whose detail is described below with reference to FIG.  5 . In this embodiment, the viewing head includes a optic system including a lens to direct incoming light axially through the tube  72  to an end thereof distal to the viewing head  92 . Disposed at the end of the tube  72  distal to the viewing head  92  is an eyepiece structure  80  that includes a flexible eyepiece  81  attached to a holder  82 . The holder  82  is attached to the end of a secondary tube  73  that is axially movably disposed within and relative to the tube  72 . A seal between the tubes  72 ,  73  is provided by an adapter sleeve  76  that is coupled by rivets  77  to the end of the tube  72  and includes an O-ringed bore  78 . Carried at an end of the secondary tube  73  distal the eyepiece structure  80  is a lens  74 . Movement of the secondary tube  73  is manually effected and constitutes the focusing of the device  1 . 
     With particular reference now to FIG. 5 the viewing head  92  is shown in detail. The viewing head is disposed at an end  94  of the tube  72  and includes a holder  95  situated within the end  94  and coupled thereto via rivets  96 . An end cap  98  is threadedly received on the end  94  providing a seal. The holder  95  carries a lens  97  having an axial focus corresponding to the axis of the tubes  72 ,  73  such that light entering the lens  97  is directed to the lens  74  of the secondary tube  73 . Disposed in a side wall of the end  94  is a bore  99  in which is situated a transmissive element or window  100 , again preferably being a sapphire window. Light enters through the window  100  and is directed by a reflector or mirror  101  disposed at a 45 degree angle to reflect and direct the received light axially to the lens  97  which directs the light to the lens  74 . While the secondary tube  73  is carried by the tube  72 , variable focusing is achieved by the axial movement or displacement of the secondary tube  73  relative to the tube  72 . It should also be noted that the device presented in FIGS. 4 and 5 is generally used with a separate light source while any image is viewed by the eye of the observer. 
     With reference now to FIGS. 6 and 7 there is shown another embodiment of the present optic or viewing device  1 , here an automatically actuated viewing device having an electronic optic device. Again, the optic device includes a tubular body or cylinder  104  retained between an upper head  105  and a lower head  106  by bolts  107 . A main tube or cylinder  108  extends through O-ringed bores  109 ,  110  respectively in the heads  105 ,  106 . In this manner the tube  108  is axially movable relative to the body  104  and heads  105 ,  106 . Again, the outer surface of the tube  108  and the inner surface of the body  104  defines an internal cavity that is divided into a first variable volume  112  and a second variable volume  113  by an annular O-ringed sleeve  111  that surrounds the tube  108  between the heads  105 ,  106 . The head  105  includes a conduit  114  that provides communication between the first variable volume  112  and a valve  115  (atmosphere) while the head  106  includes a conduit  116  that provides communication between the second variable volume  113  and a valve  117  (atmosphere) wherein selective evacuation or application of hydraulic or pneumatic means (not shown) effects axial movement of the tube  108  such that the viewing head  118  carried by the tube  108  may be inserted at various depths into the vessel (not shown) or retracted therefrom. 
     With additional reference to FIG. 7, the viewing head  118  is shown. In this embodiment, the viewing head is disposed at an end  120  of the tube  108  which is sealed by a threadedly received end cap  121 . An aperture  122  is disposed in a side wall of the end  120  in which is disposed a viewing window  123 , again preferably a sapphire window. Retained adjacent the viewing window  123  is a camera head  124 . The camera head  124  can be of any suitable type, however preferably used are electronic analog or digital board cameras such as those manufactured by Marshall Electronics Inc. of Culver City, Calif. Especially suited for the present application is the Marshall ultra-miniature color board camera with flexible head, known as the V-1234 &amp; V-1234XL models, in which the camera lens is coupled to a circuit board via a ribbon cable or jumper, however, other suitable board cameras may be utilized. In FIG. 6, the camera  124  is coupled via leads  125  to a circuit board  127  contained in an enclosure  126  disposed at the end of the tube  108  distal to the viewing head  118 . The leads  125  extend through the interior of the tube  108 . The circuit board  127  is coupled to a source of power (not shown) that can be in the enclosure  126  or external thereto. Additionally, the circuit board  127  is adapted to be coupled to a computer (not shown) or other device according to the manufacturer&#39;s specifications in order to convert the electrical signals into a viewable image. A ring  128  is also disposed about the tube  108  external to the head  105  for manual axial movement of the tube  108 . 
     It should here be noted that all of the automatically actuated embodiments may be manually operated should hydraulic or pneumatic means not be available or working. 
     Referring now to FIGS. 8 and 9, there is shown a further embodiment of the present viewing device  1 . Here, there is depicted a viewing device utilizing a board camera as in FIGS. 6 and 7, but with an integral light source. The viewing device  1  includes a cylindrical body  130  retained between a first head  131  and a second head  132  by a plurality of bolts  133 . The first head  131  includes an O-ringed bore  134  and the second head  132  includes an O-ringed bore  135  through which is axially movably disposed a tube or cylinder  136 . An annular O-ringed sleeve  137  is disposed about the cylinder  136  between the first and second heads  131 ,  132  and defines a first variable volume  138  and a second variable volume  139  on either side thereof between an inner surface of the tube  130  and an outer surface of the cylinder  136 . The first head  131  includes a conduit  140  providing communication between the first variable volume  138  and a valve  141  (atmosphere) while the second head  132  includes a conduit  142  providing communication between the second variable volume  139  and a valve  143  (atmosphere). Selective introduction and evacuation of the variable volumes  138 ,  139  through the valves  141 ,  143  by pneumatic or hydraulic pressure effects axial movement of the cylinder  136 . However, should manual operation be desired, a handle  162  is provided on the cylinder  136  which also serves as an axial stop for the cylinder  136 . A second cylinder or tube  145  is coaxially disposed within the interior  146  of the tube  136 , being fixedly coupled thereto. At one end of the tube  145  is a lens set having a first and second lens  147 ,  148  adapted to transmit and direct light therethrough. A light source (not shown) would be provided that would be directed through the tube  145  and into the lenses  147 ,  148 . Such a light source system is used in conjunction with a viewing head  144 . 
     The viewing head  144  is disposed at one end of the cylinder  136  opposite to an enclosure  160  disposed at another end of the cylinder  136 . The enclosure  160  housing any necessary circuit boards  161  for the components disposed in the viewing head  144 . With specific reference to FIG. 9, the viewing head  144  is depicted in greater detail. The viewing head  144  is at one end  150  of the cylinder  136  and includes a threadedly received end cap  151 . A first aperture  152  is disposed in a side wall of the end  150  in which is disposed a window  153 , preferably a sapphire window. A camera  154  is situated adjacent the window  153  whose leads  155  extend along the interior  146  between the tubes  136 ,  145  and into the board  161 . A second aperture  156  is disposed in the side wall of the end  150  axially above the first aperture  152  in which is disposed a window  157 , again preferably a sapphire window. A 45 degree angled mirror or reflector  158  is situated within the viewing head  144  so as to receive light from the lenses  147 ,  148 , and direct the light out through the window  157 . This projects the light into the interior of the pipeline for pickup by the camera  154 . The camera  154  is as described above. In this embodiment, the separate light source as depicted in FIG. 1 would generally not be necessary as the two are integral. 
     With reference now to FIGS. 10,  11  and  12 , there is depicted another embodiment of a viewing device. The viewing device of FIGS. 10-12 is permanently installed within a structure. Depicted in FIG. 10 is a section of pipe generally designated  164  defining an interior  165 . Shown disposed in the interior  165  is a vane device  166 . The vane device  166  is representative of anything within the pipe section  164  that needs to be viewed. Strategically disposed in a side wall of the pipe section  164  is a viewing assembly  168 . The viewing assembly  168  includes a bore  169  in a side wall of the pipe section  164  and preferably an angle bore to be able to effectively view the interior  165 . A sleeve  170  is disposed in the housing and retains a window  171  therein, preferably a sapphire window. Situated adjacent the window  171  is a camera  172  having leads  173  in communication with a circuit board (not shown), the camera type disclosed above. A light source  176  is disposed adjacent the camera  172 . Referring to FIG. 12, a bottom view of the viewing assembly  168  is shown. A camera lens  175  is disposed adjacent the light source  176  as seen through the window  171 . 
     With additional reference to FIGS. 13-17 there is depicted yet another embodiment of the present viewing device  1 . A cylindrical body  180  is retained between a first head  181  and a second head  182  by a plurality of bolts  183 . The first head  181  includes an O-ringed bore  184  and the second head  182  includes an O-ringed bore  185  through which is axially movably disposed a cylinder or tube  186 . Disposed about the cylinder is an annular, O-ringed sleeve  187  that together with an inner surface of the cylinder  180  and an outer surface of the cylinder  186  between the first and second heads  181 ,  182  defines a first variable volume  188  and a second variable volume  189 . The first head  181  includes a conduit  190  providing communication between the first variable volume  188  and a valve  191  (atmosphere). The second head  182  includes a conduit  192  providing communication between the second variable volume  189  and a valve  193  (atmosphere). Again, by selective application and evacuation of the variable volumes  188 ,  189 , axial movement of the cylinder  186  may be effected. However, for many movement and as an axial stop, a ring  196  is provided about the cylinder  186 . Disposed within the cylinder  186  is a fiberscope  198  that is retained by a sleeve  194  that is riveted  195  to an end of the cylinder  186 . The fiberscope has a flexible optic guide  199  that extends to the viewing head  200 . Such a fiberscope may be that manufactured by Olympus America, Inc. Industrial Products Group of Melville, N.Y. 
     The viewing head  200  may take different forms as exemplified in FIGS. 14 and 15. Referring to FIG.  14  and as depicted generally in FIG. 13, the viewing head  200  is disposed on an end  201  of the cylinder  186  with an end cap  202  threadedly received thereon. Within the end  201  is a sleeve  203  that carries an optical viewing tip  206  of the fiberscope  198 . With additional reference to FIG. 16 the optical viewing tip  206  includes a body  212  and a side field of view optic tip  213 . Thus, an aperture  204  is disposed in a side wall of the end  201  in which is received a window sealed by O-rings  205  and, preferably, a sapphire window. 
     With reference to FIGS. 15 and 17, an end or front view optic tip  210  is shown. The end cap  202  includes an aperture  208  in which is disposed a viewing window  209 , preferably an O-ringed sapphire window. The optic tip  210  includes a body  215  and a front direction of view head  216 . 
     It should be understood that various types of optic viewing tips are available depending on the desired field of view and direction of view. This make the fiberscope embodiment versatile. 
     Referring lastly to FIGS. 18-21, there is depicted a manual embodiment of the present viewing device  1 . FIG. 18 depicts the viewing device  1  with a first head  220  having a first bore  221  and a second head  222  having a second bore  223  retained by bolts  224 . An axially movable tube  226  is disposed in the first and second bores  221 ,  223  and terminates at one end in a viewing head  227 . As depicted in FIGS. 19-21, the viewing head  227  may take various forms. FIG. 19 depicts an optic system utilizing a lens  229  and reflector  230 . The end of the tube  226  includes an end cap  231  threadedly received on the end and a sleeve  228  that carries the 45 degree angled reflector  230  and lens  229  for axially directing any received light. An aperture  232  is disposed in a side wall of the end in which is a viewing window  233 , preferably a sapphire window. FIG. 20 depicts the use of a board camera  237  disposed adjacent a preferably sapphire viewing window  236  situated in an aperture  235  in the side wall of the end of the tube  226 . Leads  238  extend from the camera  236 , of the kind described above, to an associated circuit board (not shown) preferably in an enclosure (not shown) at the other end of the tube  226  (not shown). In FIG. 21, an end cap  240  is threadedly received on the end of the tube  226  while a first aperture  241  is disposed in a side wall with a viewing window  242 , preferably a sapphire window, disposed therein. A camera  243  of like kind to those above, is disposed adjacent the window  242  for receipt of incoming light. Leads  244  again are coupled to a circuit board (not shown). Additionally, a second aperture  245  is disposed in a side wall of the end adjacent the first aperture  241 . Again, a window  236 , preferably a sapphire window is disposed in the second aperture  235 . An angled mirror  247  is adapted to direct internal light out through the window  242  to provide light for the camera  242 . 
     It should also be understood that the present invention is adapted for use in high pressure environments such as product-flowing pipelines. Therefore, the viewing head is constructed so as to withstand such pressures, and thus the preference for a sapphire window. 
     It is also apparent from the foregoing, that the present invention is not limited to the embodiments shown. Other equally effective embodiments are contemplated and within the scope of the present invention.