Abstract: Disclosed is a threaded pipe connection. The connection includes tubular externally threaded male members and a tubular internally threaded female coupling threadedly engaged with the male members. The male members include a continuous thread having a first preferably straight portion and a second tapered portion. The thread includes a form having stabbing and load blanks and an axially extending crest and root. Throughout the thread, lead as measured along the load flanks is constant and the length of the crest and depth of the load flanks are constant.

Abstract: An improved elastic gasket-type pipe coupling device for providing a leak-proof joint between two adjacent pipe segments in a pressurized plumbing system. According to the preferred embodiment of the invention, the pipe coupling includes a cylindrical elastic gasket, a metallic compression band circumferentially disposed about the elastic gasket, and a plurality of tensioning bands attached to and encircling the compression band. The cylindrical elastic gasket includes an inwardly extending, centrally disposed separation ring and at least two integral, inwardly extending sealing rings symmetrically disposed on opposing sides of the separation ring. An enhanced pressure-resistant seal is achieved by locating the tensioning bands at points immediately adjacent to and on both sides of each sealing ring.

Abstract: A system and method for thickening the end of a pipe or rod for receiving tapered threads is disclosed. A metal sleeve is metallurgically bonded to the outer surface of the end portion of a well pipe by a high-energy impact of the sleeve colliding radially inward against the end of the well pipe. The impact is produced by the detonation of an explosive charge propagating uniformly around the sleeve. A castable metal having a substantially lower melting temperature than the melting temperature of the pipe is deposited within the pipe and is permitted to solidify in situ to form a core for absorbing the high-energy impact of the collision and for limiting the radial contraction of the pipe in order to preserve its inside diameter. A thread is machined along a tapered path which penetrates the metallurgically bonded interface of the sleeve and pipe.

Abstract: Threaded pipe joint in which tip of the male member engages shoulder within the female member and any excess in the outer diameter of the male member over the corresponding inner diameter of the female member is so small that the hoop stress in the female member does not exceed the axial stress therein.

Abstract: Connector means for joining together two adjacent pipe members in a fluid/pressure tight relationship comprising an externally threaded male element cooperatively engageable with an internally threaded female element, the male and female elements each respectively including three adjacent complementary annular sealing surfaces positioned axially adjacent the threaded portion associated respectively therewith, the three adjacent complementary sealing surfaces being arranged in an irregular pattern such that when the male and female elements are threadingly secured together, the three adjacent sealing surfaces associated respectively with the male and female elements sealingly engage one another to form three independent adjacent pressure-tight seals.

Abstract: Joint and joint components designed to withstand axial compressive loads join a pair of pipe sections end-to-end, the adjacent ends of the sections being threaded. A coupling member for connecting the threaded adjacent ends of the pipe sections includes threads interengaged with the threads on the adjacent ends of the pipe sections. An abutment member located between the outer ends of the pipe sections is shaped so that the ends of the pipe sections abut against opposite sides of the abutment member. Each pipe section includes a shoulder which is formed integral with and extends circumferentially around the section, the shoulder including an angled surface which faces the angled surface on the other pipe section and is oriented at an angle substantially the same as the surfce on the other pipe section, each surface terminating at a circumferential edge which is closer to the edge on the other pipe section than is any other portion of its respective surface.

Abstract: A tube coupling for coupling together one tube to another tube which have predetermined interior and exterior diameters comprises an outer sleeve which has an interior bore with a sealing element lining the bore of an elastic material. The sealing element has an exterior positively engaged sleeve and for this purpose advantageously includes exterior radially extending ribs which engage into dovetail radially extending grooves of the outer sleeve. The sealing element lining the bore of the tube is of an elastic material and it is formed substantially symmetrically in respect to its radial mid plane and includes at each end a plurality of inwardly directed sets of sealing protuberances following each other with cavities adjacent these protuberances into which the protuberances can be deflected by the engaged tube.

Abstract: A tube securing mechanism for retaining a resilient tube on a rigid tube connector, for use in a patient breathing circuit of a respirator. In one embodiment of the invention, the tube securing mechanism is a clamp (22) having a circular band (30) with a peripheral break in it, and two integral arcuate portions (32 and 34) hinged to the band and to each other, to form a toggle mechanism by means of which the clamp is opened and closed. A pair of integral teeth (50) on the band and another pair (52) on one of the arcuate portions of the clamp, engage each other to protect the hinges of the clamp from unnecessary stress. In another embodiment of the invention, a tube (10) has two internal annular features (64 and 66) that are complementary to corresponding annular features (60 and 62) on a connector (12'), to hold the tube more securely on the connector.

Abstract: A corrosion-resistant pipe coupling made of carbon steel has on its inner surface an intermediate annular projection directed radially inward. At least an innermost part of the annular projection is formed or corrosion-resistant material such as stainless steel. The annular projection is covered by a corrosion-resistant annular member or which is secured by friction welding, electron beam welding, an adhesive or mechanical engagement. The annular member prevents corrosion of the coupling by corrosive fluids flowing in pipes.

Abstract: A pipe joint consisting of first and second pipes having ends juxtaposed to provide a fluid tight interconnection therebetween. An outer surface of the first pipe defines a first circumferential coupling groove and a first circumferential seal groove disposed between the first coupling groove and the connected end of the first pipe. An outer surface of the second pipe defines a second circumferential coupling groove and a second circumferential seal groove disposed between the second coupling groove and the joined end of the second pipe. Fitted over the outer surfaces of the first and second pipes is a resilient sleeve covering the first and second seal grooves. A clamp assembly with inward projections overlays the sleeve and is radially collapsible to forcibly engage the resilient sleeve.

Abstract: A pipe joint in which a metal-to-metal seal is provided on the exterior of the pipe, a torque shoulder provides a further metal-to-metal seal and a still further seal is provided by a resilient ring. The box is protected against ballooning which might result in jump out of the threads by proportioning the thickness of the box at the point of seal at the maximum diameter of seal to the outer diameter of the box as compared to the full wall thickness of the pipe related to the outer diameter of the pipe.

Abstract: A pipe joint with premium threads having both metal-to-metal and polymeric seals to block fluid leakage through the joint. A polymeric seal ring is preferably carried within an annular groove in the box end. Metal sealing surfaces, each having a different inside diameter, are provided on opposite sides of the annular groove to form metal-to-metal seals with two compatible metal sealing surfaces on the exterior of the pin member. The joint is thus characterized by two metal-to-metal seals formed on opposite sides of the annular groove to trap the seal ring therebetween. The metal-to-metal seals cooperate to prevent undesired extrusion of the seal ring.

Abstract: In a pipe coupling for connecting pipes as fluid conduits, a split clamping ring, which is of arcuated configuration in cross section, has a pair of spaced circular sharp edges directed toward the pipe for firm engagement therewith and is disposed in an annular groove formed internally of a body so as to be slightly displaceable relatively to the groove in an axial direction of the body when a certain axial force is applied to the pipe; a deformable sealing ring is disposed in another annular groove formed internally of the body; and a plurality of depressing members are provided for adjustably compressing the clamping ring diametrically.

Abstract: A quickly-attachable pipe coupling comprises a flexible tube having an internal diameter approximately equal to the outer diameter of the pipe to be coupled, and a cylindrical spring overlying the flexible tube. The cylindrical spring includes a closely-wound coil of flat spring material having more than one turn, and having an inner diameter in its relaxed condition less than the outer diameter of the flexible tube. The coil spring is partially uncoilable under stress to open by increasing its inner diameter at least to the outer diameter of the flexible tube. Thus, the flexible tube and the cylindrical spring thereover, when in its stressed open condition, may be applied over the end of the pipe to be coupled, whereupon the cylindrical spring may be relaxed to close and to cause it to compress the flexible tube into tight engagement with the pipe for the complete length of the coil spring.

Abstract: A swivel coupling apparatus includes a pair of aligned metal pipe sections having grooved outer ends for connecting to hoses and rigid pipes by releasable clamp units. A gasket is disposed between the smooth end faces and an outer clamp housing encircles the end portions to mechanically connect the pipe sections. The pipe sections have outer shoulders with inclined clamp walls. The clamp housing includes a pair of semi-circular members having bolt clamping lugs for drawing the members onto the shoulders. The members having outer side clamp legs defining a cavity. A central rectangular spacer projects partially into the cavity for location between the outer portion of the end faces. The cavity has annular base walls between the spacer and side legs aligned with and outwardly spaced from the outer peripheral walls of the shoulders. Grease fittings to the opposite sides of the spacer provide for introducing of grease into the free space. The spacer has a smooth inner wall forming a backing for the gasket.

Abstract: A pipe coupling for connecting pipes end to end in fluid tight fashion. A sleeve having open ends receives the end portions of the pipes. The sleeve has a pair of ribs on its inside surface which snap into mating grooves on the pipe ends when the pipe ends are fully inserted. A clamping band is tightened on the sleeve to squeeze it against the pipes and to deform the ribs such that they completely fill the grooves. A series of striations on the inside surface of the sleeve also seal against the pipes.

Abstract: In a pipe coupling including a housing having a bore for receiving the end of a pipe, and clamping means for clamping the pipe to the housing, the clamping means is formed on its inner face with a first circumferentially-extending recess for receiving a first clamping ring, and with a second circumferentially-extending recess axially spaced from said first recess for receiving a second clamping ring of a different hardness than the first clamping ring, to thereby enable the coupling to be used for coupling pipes of different hardnesses by selecting the appropriate clamping ring and inserting it into its respective recess.

Abstract: An elastomeric joint (10) for use with couplings (100), pipe (201 to 204), connectors (205) and the like is described. The elastomeric joint is particularly adapted to provide ease of mounting of the pipe, particularly plastic pipe, between couplings embedded in the floors (500 and 500a) in the construction of buildings.

Abstract: A pipe coupling comprises a first pipe-encircling member having an outwardly extending peripheral flange, a sealing ring disposed within the first member to provide a seal between the member and a pipe, a second pipe-encircling member having an outwardly extending peripheral flange, a pipe-gripping collar within the second member having an external frusto-conical surface so arranged that, upon axial movement of the second member towards the first member, the collar is contracted radially to grip the pipe, and a number of axially extending clamping bolts passing through registering holes in the outwardly extending flanges, so that by tightening the clamping bolts the second member is moved axially towards the first member, causing the collar to grip the pipe, without relative rotation between the members.

Abstract: The invention is directed to a multilayer pipe joint and, more particularly, to a pipe joint for effectively joining sections of pipe having an outer metal casing, an inner plastic pipe, and an annular cement grout sleeve. The joint comprises a dual material ring which is at least partially fitted within a recessed annular space at the end of each multilayer pipe section. The metal casing may be welded to the outer steel component of the ring, and the inner plastic pipe is sealed against the plastic component of the pipe.

Abstract: Separable joint for oil well pipe in which both the male and female members have a cylindrical threaded section adjacent a frusto-conical thread section, and the female member has an internal shoulder against which the end of the male member seals.

Abstract: A connection between two pipes of a pipeline includes a pair of coupling members having externally threaded ends with sealing surfaces projecting from the ends. The threaded ends are advanced into opposite ends of an insulating sleeve fabricated of electrically nonconductive material. Internally threaded end portions of the sleeve are separated by an annular recessed portion. A resilient, nonconductive annular spacer is retained within the annular recessed portion. The spacer includes a pair of inclined inner sealing surfaces positioned in overlying sealing relation with the coupling member sealing surfaces and an outer sealing surface sealingly engaging the insulating sleeve to form a fluid and pressure tight seal around the annular space between the coupling members and the insulating sleeve in addition to electrically insulating the coupling members from each other.

Abstract: A threaded joint for well casings and tubings includes a coupling or integral socket into which pipe sections are threaded. The coupling or socket includes an inner, unthreaded portion and an outer portion having threads on its inner surface. The pipe sections include an end having a threaded portion and an unthreaded nose portion at the outer end of the threaded portion. The nose portion terminates with an annular surface and includes a plurality of convex surfaces of revolution extending circumferentially of the nose portion, all of which surfaces are adapted to engage the unthreaded portion of the coupling or socket to establish a fluid-tight seal. The thread construction is a modified buttress type with relatively flat crests and roots. An interference fit occurs between thread portions not likely to be damaged during handling, and clearance between other thread portions permits the joint connection to be made with reduced friction and with reduced concern for machining tolerances.

Abstract: A split ring pipe spacer used to separate a pipe from the fitting shoulder during welding. The spacer has yieldable protrusions for the purpose of maintaining proper spacing and alignment of the pipe and fitting during welding.

Abstract: Method and apparatus by which joints of seamless pipe are rapidly and economically fabricated into a fluid conveying pipeline. Steel tubular fluid conducting members in the form of pipe joints are joined together by a steel coupler sleeve. The sleeve has opposed cavities which receive adjacent marginal ends of the members. Each marginal end of the pipe is forced into one cavity of the sleeve with great force such that the sleeve cavity holds the pipe ends together with a strong friction fit. A sealing substance is applied to the marginal ends of the pipe. A special hydraulic machine engages and forces the marginal ends of the pipe into the sleeve cavities with a twisting motion, which enhances the connection effected between the sleeve and the marginal end of the pipe.

Abstract: Elastomeric pipe separators (14) are interlocked with an internal stop collar (10a) of a pipe coupling (10) to enable pipes (16 and 18) to be inserted as far as they will readily go into the pipe coupling (10) and yet allow for thermal expansion of the pipes (16 and 18) without damage to the pipes (16 and 18) or coupling (10).

Abstract: A swivel coupling apparatus includes a pair of aligned metal pipe sections having grooved outer ends for connecting to hoses and rigid pipes by releasable clamp units. A gasket is disposed between the smooth end faces and an outer clamp housing encircles the end portions to mechanically connect the pipe sections. The pipe sections have outer shoulders with inclined clamp walls. The clamp housing includes a pair of semi-circular members having bolt clamping lugs for drawing the members onto the shoulders. The members having outer side clamp legs defining a cavity. A central rectangular spacer projects partially into the cavity for location between the outer portion of the end faces. The cavity has annular base walls between the spacer and side legs aligned with and outwardly spaced from the outer peripheral walls of the shoulders. Grease fittings to the opposite sides of the spacer provide for introducing of grease into the free space. The spacer has a smooth inner wall forming a backing for the gasket.

Abstract: An interconnector for the coaxially adjacent permeate tubes of filtration apparatus comprises a molded elastomeric spheroidal body having opposed coaxial bores for receiving the tube ends which extend from filter membrane modules. Complementarily shaped interdigitated pairs of anti-telescoping devices are interposed between membrane modules in mutual interacting relationship and without contacting the interconnector.

Abstract: A pipe coupling has a main body including (a) a threaded portion adapted for threaded engagement with an inside-coated pipe having a mating threaded end portion, (b) an annular groove and (c) an annular projection, the members (a), (b) and (c) being located on the inside circumferential surface of the main body in this recited order from each open end of the main body toward the central portion thereof, a short cylindrical body having one end abutting the annular projection and being mounted within the main body, and an annular packing mounted within the space defined by the threaded portion (a), said annular groove and the peripheral surface of the cylindrical body. A pipe joint connection is provided by threadedly engaging inside-coated pipes with the threaded portions of the coupling. The pipe coupling of the invention permits a leakage-free pipe joint connection on the job by simply threading inner-coated steel pipes and threadedly connecting these pipes through the coupling.

Abstract: An adapter for connecting a plastic pipe system to a metallic pipe system; including an elongated, plastic sleeve having a first end thereof adapted to be joined to a plastic pipe system and a second end thereof adapted to be joined to a metallic pipe system and an elongated, metallic reinforcing sleeve, having an outside diameter substantially equal to the inside diameter of the second end of the plastic sleeve, a length less than the length of the plastic sleeve and a significant portion of one end tapered from the diametric exterior thereof inwardly and toward the one end thereof, mounted in the second end of the plastic sleeve with its tapered end toward the interior of the plastic sleeve. A pipeline structure including the adapter joined at one end to a plastic pipe system and the other end joined to a metallic pipe system is also described.

Abstract: A fitting for connection to a metal plain end pipe includes a generally cylindrical socket section sized to receive and cradle a pipe end portion, an annular seal in the socket section for forming a fluid-tight connection between the pipe end portion and fitting, and a locking device extensible into the socket section for securing the pipe end portion to the fitting. The socket section has a first bore extending from an exterior surface substantially through the socket wall and a coaxial, second bore of lesser diameter than the first bore extending the remainder of the way. The locking device includes a shaft having a head end and an opposite tip end for extension through the first and second bores and inwardly of the socket wall interior surface for engagement with a wall of a pipe end portion positioned in the socket section. A ring seal around the shaft engages a side wall of the first bore for providing a fluid-tight engagement between the shaft and the side wall.

Abstract: A cementable coupling for plastic pipe, that may be employed whether the parts are wet or dry, including cementable fitting and sleeve members that initially provide a dry seal near the end of the pipe, permitting initial drying of the pipe upstream of the dry seal, and enable later cementing of these members together and to the pipe at a location upstream of the dry seal.

Abstract: A coupling (10) for plastic pipe (100, 101, 102, 103) which is adapted to be embedded in a concrete floor (300) and to form part of a fluid flow path with the pipe (100 to 103) is described. In particular, the coupling (10) includes a tube (11), preferably integrally molded of plastic, with (1) an integral annular rim (17) inside the coupling (10) with parallel shoulders (18 and 19) perpendicular to a longitudinal cylindrical axis (14) of the tube (11) and with an annular face (20) parallel to the axis between the shoulders (18 and 19), (2) an attachment means, preferably an annular flange (21) with tabs (22) for nails (500) or the like, at one end of the tube (11) adapted to be secured to a form such as a wooden form for pouring the concrete floor (300) around the pipe (100 to 103) and coupling (10) and (3) a removable cover (23) at the end of the tube (11) adjacent the attachment means (21) and adapted to prevent poured cement (300) from entering the inside of the tube (11).

Abstract: A coupler structure which facilitates the internal joining of a first length of hollow plastic pipe having internal corrugations defined by a plurality of alternating peaks and valleys to a second length of similar pipe or to some other structure. The coupler is molded from plastic to have at least one cylindrical end portion dimensioned for longitudinal receipt in the second length of tubing or other structure which is to be coupled to the first length. This one end portion includes a plurality of integrally molded cleats extending generally radially outward thereof. The cleats are selectively movable between first locking positions for lockingly engaging the second tubing length valleys and second non-locking positions which permits forced insertion of the coupler one end portion into the second tubing length. The cleats are hinged to the one end portion generally laterally thereof and are continuously urged toward the first position by the resilient nature of the plastic construction.

Abstract: A flange compression pipe coupling wherein the end portions of the pipes to be coupled are surrounded by an inner jacket consisting of ductile metallic material. The inner jacket is surrounded by a radially deformable outer jacket which is biased against the exterior of the outer jacket by two flanged rings having conical internal surfaces. The outer jacket causes plastic deformation of the inner jacket until the latter sealingly engages the end portions of the pipes whereupon the extent of plastic deformation of the inner jacket remains unchanged.

Abstract: A coupler for connecting adjacent ends of clay pipe with a generally cylindrical flexible sealing member of urethane or the like having opposing inner and outer central grooves which extend circumferentially and pairs of circumferentially extending outer support grooves flanking the outer central groove. Rigid rings of fiberglass are provided in the grooves. The central ring has an inwardly extending stop portion and unitary sealing lips are provided on the interior surface of the sealing members between the support grooves of each pair.

Abstract: The pipe coupling includes a hollow cylindrical body and pipe registering means projecting radially inward therefrom centrally thereof. The body has a pair of inner annular grooves respectively adjacent opposite ends for the reception of sealing rings. Both the body and the pipe registering means are formed of glass fiber reinforced thermosetting resin and each contains glass filament windings. A plastic film strip between the body and the pipe registering means maintains them separate as the resin of both is cured. Thereafter, any cracking of the pipe registering means will leave the body intact and a good pipe joint will be maintained.

Abstract: A coupling for sealing two tubes together in end-to-end sealing engagement, comprises an outer tubular sleeve having an interior bore with a plurality of radially extending grooves therein at spaced axial locations and an inner tubular seal arranged within the outer tubular sleeve and having an exterior wall with radially outwardly extending ribs which engage into the respective grooves. The seal has an interior bore with an entrance diameter at each end at least as large as the tubes to be joined or larger so as to have an inwardly tapered entrance. The seal includes a bore wall defining a compression flange with an inwardly, gradually tapering wall adjacent each entrance which tapers inwardly in an axial direction for diameters substantially smaller than the tube. The compression flange also includes an opposite steeply tapering wall which extends in an axial opposite direction to the gradually tapering wall.

Abstract: A pipe coupling is disclosed, of the type comprising an annular elastic gasket fitted over the two adjacent pipe ends and tightened down with encircling clamp bands. The coupling includes a plastic band surrounding the elastic gasket, with overlapping ends tapered in thickness. The metal clamp bands encircle the plastic band and are retained in place by ridges forming channels on the outside surface of the plastic band.

Abstract: A coupler which is for tubing and which has a tube receiving bore therein. A sealing ring, spacer ring and lock ring are coaxially located within the coupler bore. When a tube is inserted into the coupler bore, the sealing ring makes contact between the coupler and tube with the spacer and locking ring cooperating to cause the locking ring when the tube is pressurized to firmly engage the tube, thus preventing the tube from being withdrawn from the coupler.

Abstract: A hollow tubular member is provided with a plurality of obliquely oriented slots creating therebetween a series of ring elements which are offset from the transverse plan of the tubular member to provide an effective reduction of the internal diameter thereof for lockingly engaging an elongate element inserted within the tubular member. Both ends of the tubular member may be similarly slotted to provide an in-line coupling between two elongate members. Also disclosed is a method for forming the sleeve from a flat blank of material. Suitable modifications may be made to permit the sleeve to be attached to a support plate such as the wall of an electrical enclosure or the like.

Abstract: A fitting for forming a sealed joint with a plain end portion of pipe includes a semi-elastic sleeve member having enlarged ends with annular sealing gaskets received therein. An inwardly extended ridge member is circumferentially arranged at the longitudinal midportion of the sleeve member and provides an abutment surface for limiting the inward extension of a pipe end. A plurality of circumferentially spaced rib-shaped protuberances are positioned within the sleeve member and extend radially inwardly from the interior surface for compressibly gripping and supportably engaging the pipe end within the sleeve member.

Abstract: A fitting for the end of a plastic pipe segment includes a body having an open-ended bore in which the pipe segment is received. A wedge-shaped grip ring and annular gasket are fitted over the pipe segment and compresses against an annular shoulder provided in the sidewall of the bore by a compression nut threaded into the open end of the bore. Abutting complimentarily inclined surfaces on the compression nut and the grip ring provide simultaneous radial compression of the grip ring and axial compression of the gasket when the compression nut is tightened. A sleeve-shaped stiffener within the pipe segment prevents deformation of the pipe wall. A plurality of radially extending serrations on the inside surface of the grip ring and on the outside surface of the stiffener engage the inner and outer surfaces of the pipe wall to secure the pipe segment to the fitting. An electrically conductive collar may be provided within the bore to establish electrical continuity between adjacent pipe segments.

Abstract: To join two pipe sections carrying fluids that may be at relatively high pressures, a coupling body into which the ends of the pipe sections are inserted has a gasket seal at each end thereof. In order to electrically insulate the sections of pipe from one another, an insulating sleeve is located along a length of the internal surface of the coupling body. An insulating stop member is slidable within the sleeve to separate the ends of the sections of pipe, the stop member being prevented from entering the length of the coupling body that does not have an insulating sleeve. Threads for coupling nuts utilized in achieving the fluid tight seal are formed in the outer surface of the coupling body at each end thereof.

Abstract: A coupling for joining spiral underground drainage pipes includes a cylinderical body with an inner circumferential flange and locking projections. When the coupling is rotated on to the drainage pipes the ends of the pipes are held flush on the flange and the inner surface of the flange forms a smooth continuation of the inner surfaces of the pipes.

Abstract: A male end is inserted in a socket with radial clearance. An annular elastically yieldable sealing element has an outer heel portion disposed in an inner groove in the socket. A single lip portion on the sealing element extends inwardly of the socket and has a radially inner end which grips the male end. The heel portion has, at rest, an axial dimension which is of the same order of magnitude as its radial dimension and exceeds the axial dimension of the groove. The axial dimension of the groove is greater than the greatest radial space between the male end and the edge of the groove adjacent the entrance of the socket.

Abstract: Dual conduit drill stem member includes pipe having two piece tube therewithin affixed to pipe at outer ends and inner ends coupled by composite elastomeric sleeve and telescopic metal coupling, adjacent members being connected by threaded tool joints on pipe ends and compression sealed telescopic joints on tube outer ends.

Abstract: Plastic socket of fibre reinforced thermosetting material comprising an inner push edge, a first recess at each end for positioning sealing means, which are held by means of a retaining ring which is accommodated in a second recess. The inner wall between the first recess and the push edge tapers outwardly.

Abstract: Porous, tubular core sections coated with a semipermeable membrane are joined at their ends by a simplified coupling member. Each coupling member or connector comprises a cylindrical flange member having helically ribbed or barbed nipples which fit tightly into the ends of bores of adjacent core sections. The ends of the cores abut against the circular part of the coupling member. The ribs on the nipples on the coupling member are resilient and deform when inserted. The nipples have neck parts of a smaller diameter adjacent the body part of the coupling member providing annular spaces between these neck parts and the bores of core members permitting continuous flow of permeate and cleaning solution into these spaces and helically along the nipples. There are no appendages, cavities or pockets in which permeate or cleaning solution could be trapped.