in the figures , the well casing 20 has a radial aperture 22 , an outer cylindrical surface 24 , and an inner cylindrical surface 26 . each of the different hanger members 30 , 130 and 230 shown in the different embodiments in figs . i - iii , iv and ix , respectively , has a sleeve or nipple portion 32 , 132 and 232 with an exteriorly threaded outer end 34 , 134 and 234 and at its inner end inside the casing 20 has an enlarged flange portion 40 , 140 or 240 , larger than the diameter of the hole 22 in the casing , so that the hanger member may be clamped by a nut means 60 , 160 and 260 ( described later ) against the inner wall 26 of the casing 20 . in the embodiments shown in figs . i through viii , the flange portion 40 is shown to comprise a horizontally c - shaped track having vertical inwardly extending parallel rails 42 and 142 , which may either be tapered to be narrower at their lower ends , or may have an entirely uniform cross - section and / or have a stop means 44 at their upper end , and / or at their lower end ( not shown ). in between the tracks 42 or 142 there is provided a vertical flat surface 46 or 146 having a centrally located aperture communicating with the duct in the hanger member 30 or 130 . on the opposite or back side of the flange portion 40 from that of the tracks and rails 42 and 142 , there are preferably provided a pair of parallel ridges 48 for engaging the inner surface 26 of the well casing 20 for vertically aligning the tracks parallel to the axis of the casing 20 ( see figs . ii and viii ). the flange means 240 shown in the embodiments of figs . ix and x comprises a frusto - conical central opening 246 axially aligned with the duct in the center of the nipple portion 232 of the hanger member 230 . if desired , the outer end of the nipple portion 32 or 232 may be internally taper threaded at 36 or 236 for the connection of a horizontal side pipe 50 . however , this side pipe 50 may be connected into an outward extension on the nut means 260 instead , as shown in figs . vii and viii and described later . the nipple portion 32 , 132 or 232 also may be provided with a radial hole 38 , 138 or 238 respectively , for pressurizing the gasket around the outside of the well casing 20 . the only distinction between the hanger member 30 shown in figs . i and ii and that in fig . iii is that this member in fig . iii is shown to be made of a plastic material instead of a metal such as brass . the primary distinction of the hanger member 130 shown in fig . iv is that between the flange member 140 and the inside surface 26 of the well casing 20 , there is provided a flat annular seat 148 for an interior contoured gasket 90 as will be described later . around the outer threaded portions 34 , 134 and 234 of the hanger members 30 , 130 and 230 , there are provided nut means 60 , 160 or 260 as shown in figs . i , iii and vii , respectively , which nut means provide the clamping action for clamping the flange means 40 , 140 or 240 tightly against the inside wall 26 of the well casing 20 . in the embodiments shown in figs . i , ii , ix and x , the nut means 60 comprises a simple annular nut with flat ends and threaded internally . the inner end of these nut means may be provided with a countersunk or stepped portion 62 or 162 so that this inner end of the nut means may be threaded beyond the end of the threads 34 for further urging a washer and / or gasket against the outside of the well casing 20 . however , only a gasket and not both a washer and gasket may be employed ; in which case the seat 164 for the gasket may be incorporated in the inner end of the nut means 160 as shown in figs . iii and iv . a preferred embodiment of this seat 164 for the gasket 80 has a frusto - conical surface . however , in the embodiments shown in figs . i and vii there are provided separate washer members 70 and 170 with frusto - conical seats 74 and 174 on their inner ends or sides for their gaskets 80 , and flat annular outer ends or sides 72 and 172 for engaging the inner ends of the nut means 60 and 260 . the gasket 80 correspondingly has an outer flat annular surface 82 for engagement with these frusto - conical seats 74 , 164 and 174 and an inner saddle - shaped contoured surface 84 ( see figs . v and vi ) for approximating the contour of the junction around the hole 22 of the intersection between the larger cylindrical surface 24 of the well casing 20 and the smaller cylindrical surface of the nipple portion 32 , 132 and 232 of the hanger members 30 , 130 and 230 . it is an important feature of this invention that these seats for the contoured gasket 80 have frusto - conical surfaces so as to compress the contoured gasket 80 both against the outer wall 24 of the well casing 20 as well as against the outer cylindrical wall of the nipple portions 32 , 132 and 232 . thus , any radial bisection of the saddle angle between the outer surface 24 of the well casing 20 , and the outer cylindrical surface of the nipple portion 32 , 132 and 232 should be substantially perpendicular to these frusto - conical seats 74 , 164 and 174 so that any axial compression of the gasket 80 by these frusto - conical seats will compress the contoured gasket 80 both against the outside surface 26 of the well casing 20 and the nipple portions 32 and 132 around the aperture 22 , thereby completely sealing the aperture 20 from anything outside the well casing 20 and side duct 50 , and also enabling this gasket 80 to be pressurized . as shown in fig . iv , a second contoured gasket 90 may also be provided around the nipple portion 132 inside the well casing 20 . this gasket 90 is seated in the flat annular seat 148 provided on the back side of the flange portion 140 . the seat engaging side 92 of this gasket 90 is flat and annular , while its well casing engaging surface 94 is contoured to substantially conform with the inner surface 26 of the well casing 20 surrounding the hole 22 . the saddle contours of the well casing engaging surfaces of the gaskets 80 and 90 are more clearly shown in figs . v and vi , being respectively concave and convex for sealing the saddle - shaped joint formed between the larger cylindrical surfaces of the casing 20 and the intersecting smaller cylindrical surfaces of the nipple portions . thus , the gasket 90 in combination with the gasket 80 provide an annular chamber 92 between the inside of the hole 22 and the outside of the nipple portion 132 , which chamber may be pressurized through a radial aperture 138 through the wall of the nipple portion 132 . this is pressurized by the pressure of the fluid through the nipple portion 132 . if desired , the washer 70 may be provided with an axially extending flange 173 as shown for the washer 170 in figs . vii and viii . this flange may be contoured slightly so as to be slightly saddle - shaped to retain the contoured gasket 80 , particularly at the receding sides of the casing 20 as shown in fig . viii . referring further to this embodiment shown in figs . vii and viii , the nut means 260 is extended outwardly beyond the threaded portion 34 of the nipple portion 32 and is internally taper threaded at 264 so as to fit the diameter of a different size sided pipe 50 or 50 &# 39 ;. thus , different size nut means 260 may be used for adapting a standard hanger member 30 to fit different diameter side pipes . the nut means 260 as shown in figs . vii and viii may also be provided with a second gasket seat 266 into which an o - ring gasket 268 may be seated for sealing the inner end of the nut means 260 against the washer 170 . thus an annular pressurizable chamber 267 is provided , which may be pressurized by a radial hole 38 through the nipple portion 32 of the hanger portion 30 , in that this chamber 267 is now sealed at its one end by the gasket 80 , in the middle by the o - ring 268 , and at its other end by the conical threads 264 of the side pipe 50 . a still further embodiment of a washer 270 is shown in figs . ix through xii which has a second seat 272 for a second gasket or o - ring 268 between the nut means 60 and the washer 270 . since the gasket 268 has a frusto - conical seat 272 , it also seals the gasket 280 not only against the face of the nut 60 , but also against the outer cylindrical surface of the nipple portion 232 , so that between it and the gasket 180 there is also provided an annular chamber 269 which can be pressurized from the duct in the center of the nipple portion 232 via the radial hole 238 . the other seat 274 for the gasket 180 in this washer 270 may be elliptically frusto - conical as better shown in figs . x , xi , and xii . in this case , the sealing gasket 180 may have a uniform radial cross - section such as an o - ring , in that the beveled bottom portion of the seat 274 has a saddle - shaped contour which follows substantially the saddle contour of the joint between the large cylindrical outside surface 24 of the casing 20 and the intersecting outside smaller cylindrical surface of the nipple portion 232 . this particular washer 270 is also shown to have both axially and radially extending flange portions 276 and 278 , respectively , which axially extending flanges 276 do not extend axially as far as the actual contour of the largest size surface 24 of the casing 20 as shown in fig . xi so as to permit the use of this washer 270 for different size casings 24 and 24 &# 39 ; shown in dot - dash lines . in this instance , the only contact that could occur between the flange portion 276 and the casing 20 would be along the vertical axis of the junction as shown in fig . xii . still further , the washer 280 may not have a flanged seat for the o - ring gasket 180 , but may have only an elliptical frusto - conical seat 284 as shown in figs . xiii and xiv . such an elliptical frusto - conical seat is more clearly shown in figs . xiii and xiv wherein the minor and major axes of the elliptical cone subtend apex angles β and γ respectively , and vary in between so that the angle α between the seat 284 and the outer surface 24 of the casing 20 will be substantially the same all around the hole 22 . thus , any radial bisector of the angle between the outer surface 24 of the casing and the outer surface of the nipple 32 will be more substantially perpendicular to the beveled or elliptical frusto - conical surface of the seat 284 so as to insure substantial equal pressure at all angles of the o - ring gasket 180 , completely sealing the saddle - shaped joint around the hole 22 . in figs . i , iii and ix there are shown different embodiments of elbow members 100 , 200 and 300 , respectively . the embodiments shown in figs . i , iii and vii of elbow members 100 and 200 comprise l - shaped ducts 102 , the lower ends of which have internal tapered threads 104 for attachment of a drop pipe 110 . the other ends of the ducts 102 terminate in openings in flat slide surfaces 106 which align with the openings in the flat surface 46 of the tracks in the flanges 44 of the hanger members 30 and 130 . around one of these openings may be provided annular grooves 112 for seating o - ring gaskets 114 which are compressed when the members 100 and 200 are slid in the direction shown by the arrow 116 in fig . i into the position shown in fig . vii to seal the connection between the surfaces 106 and 46 around these aligned openings . the surfaces 106 have parallel side edges which are preferably beveled at their lower ends for easy insertion between the rails 42 and 142 . these parallel sides may be tapered or wedge - shaped and / or provided with a stop engaging means at their top and / or bottom , such as hook portions 118 for engaging the stop portions 44 . if desired , these hook portions 118 may be provided with a beveled end 119 as shown in figs . i , iii and vii , which co - operates with a similar beveled surface on the back of the stops 44 for further urging the elbow members 100 into intimate contact with their hanger member 30 and 130 for further compressing the o - rings 114 . there also are provided in the elbow members 100 and 200 threaded sockets 120 , which preferably have drain apertures 122 , into which sockets 120 there are screwed pipe sections or installation rods 125 for lowering the elbow members 100 and 200 into position down the well casings 20 for attachment with the hanger portions 30 and 130 . the major distinction between the elbow members 100 and 200 shown in fig . iii , is that the latter is made out of plastic , and since there is no outside metallic nut means 160 or sleeve for reinforcing their internally threaded sockets as for the plastic nipple portion shown in fig . iii , there are shown metallic rings 124 surrounding and / or embedded in the plastic member 200 around the internally conically threaded portions 104 and sockets 120 . referring now to the elbow member 300 shown in figs . ix and x , it has an l - shaped duct 302 , the lower end 304 of which is internally taper threaded for receipt of the down pipe 110 . however , the other end of the duct 102 is provided with a frusto - conical nose portion 306 for fitting into the frusto - conical opening or seat 246 in the hanger member 230 . this frusto - conical nose 306 may be provided with an annular groove seat 308 for an o - ring type gasket 310 to seal the nose 306 in the opening 246 . in order to insure the sealing between this nose 306 and the opening 246 , there is provided a lever member 312 which has a central pivot 314 . thus lever 312 is actuated by a threaded bolt means 316 which acts on the one end of the lever 312 to push its other end against the inside wall 26 of the well casing 20 opposite the hole 22 to force and maintain the nose portion 306 into sealing engagement in the frusto - conical opening 246 . this bolt means 316 is threaded in an aperture 318 in the bottom of the conical threaded socket 320 having a drain outlet 322 . this socket 320 is for the elbow member 300 positioning pipe 125 through the center of which pipe 125 there may be inserted a wrench means 330 for rotating the bolt 316 . it should be clearly understood that although a nut means and washer and contoured gasket are employed in the embodiment in fig . i , the nut means 60 and washer 70 may be replaced by a nut 160 with a frusto - conical seat for the gasket 80 , and vice versa , for the embodiment shown in figs . iii and vii . similarly , instead of using this frusto - conical seat as shown in fig . i , the seats may have radial and axial flanges as shown in the embodiments of the washer 270 and / or if a gasket 180 of uniform radial cross - section is to be used instead of contoured gaskets 80 and 180 , the washers and / or the nut means may have gasket seats which are elliptical frusto - conical or contoured to the saddle joint around the casing hole 22 as shown , for example , in the embodiments of figs . ix through xiv . furthermore , it is to be understood that the different types of connections for the elbow members with the hanger member may be interchanged with the different types of sockets and with different type of means for holding the elbow members against the hanger members than those shown herein and as known in the prior art . thus , while there is described above the principles of this invention in connection with specific apparati , it is to be clearly understood that this description is made only by way of example and not as a limitation to the scope of this invention .