Abstract: The invention relates to a threaded swivel connector (1) for connecting a housing (3) to a member (2) by means of a hollow bolt (7). For improving the sealing effect, there have been provided specially designed sealing edges (15) of a collar (8) of the bolt (7) to seal with the housing (3) and sealing edges (21, 25) of a sealing ring (18) between the housing (3) and the member (2) to be connected. The sealing edges (15, 21, 25) are formed between inclined annular faces (16, 17, 19, 20, 22, 23), one at an acute angle to a plane (E1, E2, E3) at right angles to said axis and the other oppositely inclined at a greater angle.

Abstract: A plug valve with metal-to-metal annular sealing rings with a V shaped cross section to provide a resilient force for sealingly engage with respect to a horizontal sealing surface and a nearly vertical rotatable sealing surface and/or with a vertical sealing surface.

Abstract: A union joint capable of connecting two pipes in a perfectly sealed joint. The union joint comprises a first sleeve hermetically joined to a first pipe, a second sleeve hermetically joined to a second pipe, a metallic gasket interposed between the first and second sleeves so as to be compressed between the respective pressing surfaces of the first and second sleeves when the first and second sleeves are drawn axially toward each other and a coupling nut combined with the first sleeve so as to be screwed on the second sleeve to draw the first and second sleeves axially toward each other.

Abstract: A metal-to-metal sealing pipe swivel joint especially useful with a subsea well completion system to pivotally interconnect the subsea wellhead to a lay-away flowline, the swivel joint having an annular seal element with metallic sealing surfaces and inner and outer tubular elements, also with metallic sealing surfaces, that can be moved into or withdrawn from sealing engagement with the seal element sealing surfaces.

Abstract: Opposed ends of two tubular members are relatively displaced toward opposite sides of an annular seal to deform the seal and reduce the seal bore into approximate or actual alignment with the tubular members bore.

Abstract: The improved joint of the present invention includes a wellhead housing and its complementary member forming the joint and they include surfaces which taper both inwardly and away from the joint surfaces together with straight cylindrical sealing surfaces extending away from the inner end of the tapered surfaces. One form of improved seal includes a sealing ring having a tubular body with an external flange or hub to be clamped between the joint surfaces of the joint members, tapered external surfaces which mate with and provide a tight sealing engagement with the tapered surfaces of the joint members and tubular rims extending away from the tapered surfaces and having sufficient length to protect the straight cylindrical sealing surfaces of the joint members.

Abstract: The present invention is directed to a seal for demountable joints operating over a wide temperature range down to liquid helium temperatures. The seal has anti-extrusion guards which prevent extrusion of the soft ductile sealant material, which may be indium or an alloy thereof.

Abstract: A conduit coupling member for use with a second coupling member, comprising: a generally tubular body having a bore along its longitudinal axis; an integral and portion of the body having a nose portion and an annular groove in the bore juxtaposed the nose portion which together define a cantilever lip deflectable at least partially in a direction of the longitudinal axis; and the nose portion having an outer surface, a portion of which effects a seal when the lip is longitudinally deflected.

Abstract: A pair of flanges are fixed to a pipe end of a port of a plasma vacuum vessel and another pipe end to be connected thereto. These flanges each have a ring-shaped knife edge. A copper gasket is interposed between the respective knife edges of the two flanges. A predetermined number of bolts are tightened to fix the flanges to each other. As a result, the knife edges bite into the copper gasket, and a linear sealing load from the knife edges acts on the gasket, thereby sealing and isolating the space inside the port from the outside. The number n of bolts are given by3(B+28)/65-0.ltoreq.n.ltoreq.3(B+28)/65+0.02B,and the flange thickness t is given by ##EQU1## where B is the diameter of a circle passing through the respective central axes of the n number of bolts. Thus, the bolt number and the flange thickness are reduced without lowering the sealing performance.

Abstract: A sealing joint for use in a conduit system where an elevated pressure may exist at one side of the system comprises a pair of co-axial tubular metal sections with intermesting tapered edges which are clamped against each other by fastening means, such as a swivel nut, so as to establish a fluid tight seal formed by the conical contact area between the tapered surfaces of said edges.One of the tubular sections has a tapered edge which is at one side thereof exposed to the elevated pressure. This section has a smaller wall thickness than the tapered edge of the other tubular section so as to allow the elevated pressure to press said tapered edges onto each other.

Abstract: The invention concerns a sealing connection, based on a flat gasket of rectangular cross section, for the static sealing of construction elements. The shapes of the sealing surfaces according to the invention lead to a disc-spring-like bending of the gasket, superposed by a compressing deformation, by which an outstanding tightness even at lowest pressing forces is guaranteed. With that the application spectrum reaches from ultra high vacuum to high pressure, and from cryogenic to high temperatures.

Abstract: A serrated collar having an inner flange portion adapted to be trapped between the nut and threaded adapter of a Rosan fitting and an outer flange portion having a hole for accommodating a lock or safety wire that is splined to the outer spline of the lock ring for obviating the necessity of locating the lock wire hole directly into the casing.

Abstract: A clamp for repair of a leak in a pipeline or other structure having a flanged joint. The clamp comprises arcuate clamp sections, typically two semi-circular sections, which are assembled end to end to form a clamp ring about the flanges at the site of the leak. Each clamp section has an inner surface with spaced edges, and a seal tube of deformable metal is attached to each of the clamp sections at each of the edges, with the metal tube having a folded wall with ridges and troughs.

Abstract: A lockdown screw having a gland nut threaded into a radially extending bore in a head. The radial bore is threaded only so far as to accommodate the gland nut. A stem is threaded into the gland nut for reciprocation into or out of the main bore of the head. The threads on the stem and in the gland nut are the sole working threads of the lockdown screw. A self-energizing packing is disposed around the stem for sealing between the stem and the radial bore. There is zero extrusion gap between the gland nut and the radial bore, adjacent and outwardly of the packing. A step shoulder on the stem carries the packing with it when the stem is removed from the head. An annular backseat shoulder on the stem is engageable with an annular backseat in the gland nut, forming a metal-to-metal seal, in the event of a leak.

Abstract: Disclosed is a pipe union having a reliable metal ring seal and a resilient seal. The resilient seal is on the pin portion of the union, which has an internal seal surface. The box portion of the union has a bore to sealingly receive the resilient seal and an internal seal surface. The metal ring seal is compressed into sealing engagement with the pin portion and box portion sealing surfaces when the union pin portion and union box portion are connected together by a threaded collar. When the union is utilized in a tree cap for an underwater wellhead and the union box portion is attached to the wellhead, the resilient seal serves as a secondary seal and protects the metal seal. Well servicing risers or lubricators may be connected to the tree cap box portion.

Abstract: A hollow metallic sealing ring of low-load, self-energizing, static kind is characterized in that in radial cross-section it is of modified parabolic form with convergent margins (M) with a radial width, in its relaxed state, which is equal to substantially 7/8ths (0.875) of its maximum length (A) measured in the direction parallel to the axis of the ring.

Abstract: A compound tapered flange assembly for sealing axially aligned flanged tubular members. Opposed annular recesses are formed in each flange. Each recess has a radial shoulder tapered with respect to a transverse plane disposed between the flanges such that the axial distance between the radial plane and the shoulder at a maximum diameter is greater than the axial distance from the plane to the shoulder at a minimum diameter. Each recess also has an inside frustoconical surface tapered with respect to the longitudinal axis with a minimum inside diameter adjacent the shoulder, and a maximum inside diameter adjacent a face of the flange. A bifrustoconical annular seal ring has outside and end surfaces complementarily tapered to engage the shoulder and the inside surface of the recesses.

Abstract: A metal-to-metal packer seal for downhole use in a well that operates in a deleteriously corrosive atmosphere. The seal is formed by the cooperating ends of two pipe sections, one of which is vertically positioned in a well with an upwardly facing metallic socket. The corresponding upper pipe section includes a connector which is lowered onto the socket and carries with it at least one, and preferably a plurality of metal rings which are extruded to form a corrosive resistant circular seal between the engaged pipe socket and pipe connector.

Abstract: A fluid coupling for a corrugated pipe, comprising a coupling body having an axial through hole including a pipe insertion portion and a fluid passage portion, metallic seal means arranged on the fluid passage side of the pipe insertion portion, for sealing an end portion of a corrugated pipe pressed against the same, clamp means having at least three segments arranged in the circumferential direction and adapted to tightly hold the peripheral portion of the corrugated pipe inserted in the insertion portion, and retaining means for axially and immovably retaining the clamp means so that the end portion of the corrugated pipe is pressed against the seal means, to be sealed thereby.

Abstract: A clamping connection unit for joining two hollow cylindrical pipes together is described. The unit consists of two abutting identically constructed coupling halves (1,2), an elastic O-ring (16) placed between them and a clamping connection (15) pressing the two coupling halves together. The clamping connection is in the form of a pipe clamp and is chamfered off on the internal surfaces of the clamping jaws to form V-shaped surfaces which slide down on similarly chamfered surfaces of annular ridges at the pipe ends to connect the two coupling halves together without leaving a gap.

Abstract: A fluid connection is formed between a tube for carrying fluid and a parent material having a surface wherein the fluid passes between the tube and the parent material. The connection has a first wall in the parent material defining a flow passage having a first diameter in the parent material for the fluid. A second wall is formed between the first wall and the surface of the parent material. Threads are formed in the parent material between the second wall and the surface of the parent material for engaging an insert. A tube having an end portion placed adjacent the second wall is used in the joint wherein the tube is sealed in the parent material between the first wall and the threads in the parent material. An insert engages the threads for maintaining the tube in a sealed condition.

Abstract: The static seal comprises a semi-rigid annular part (11) shaped as a bead and first and second wings (12, 13) extending transversely with respect to the seal axis and laterally connected to the bead portion (11) in a gradual manner by means of concave surfaces with a large curvature radius. The seal has in its axial cross-section the shape of a V lying on its side, the tapered surfaces (16, 17) of the branches (12, 13) of the V being slightly inclined with respect to the planar surfaces (18, 19) of the bead (11) to which they are attached. The branches (12, 13) of the V forming the wings have an elasticity such that by flexure of said tapered surfaces (16, 17) of the V branches and slight flexure of the bead (11), the extremities of said surface may form with the planar surfaces (18, 19) of the bead (11) to which they are attached two sealing regions. Said seal is intended to be used in severe conditions of temperature, pressure, vibrations and chemical attack.

Abstract: A pipe connector device for interconnecting first and second pipe elements using a retention member removably secured to the first pipe element by load elements. The retention member is secured to the second pipe element by pipe threads or a second retention member can be secured to the second pipe element by load elements and the first and second retention members threaded together. A seal is extended along a portion of the length of the first and second pipe elements adjacent to an end portion of each of the pipe elements to prevent leakage. This provides a fluid-tight seal which is relatively independent of any pressure exerted between the first and second pipe elements by the retention member.

Abstract: A trapezoidal seal ring connection improved by the inclusion of a crush ring. The trapezoidal seal ring is sealingly engaged between an inwardly tapered frustoconical exterior surface of a male member, and an outwardly tapered frustoconical interior surface of a female member. The seal ring has an outer surface with an angle of taper substantially equal to that of the inner surface of the female member, and an inner surface having an angle of taper that is substantially equal to the angle of the taper of the end of the male member. As the male and female members are urged into mating engagement, the seal ring is wedged tightly therebetween to form a fluid-tight seal. The crush ring is positioned axially between the male and female members to fill the gap therebetween and to present a substantially uniform inside diameter to the flow of fluid through the connection. The crush ring is self-centered radially at an outer peripheral edge having a taper corresponding to that of the inside surface of the seal ring.

Abstract: A connecting capillary tube is arranged in a branch coupling and is shorter than the guide bores into which separation columns are introduced. The ends of the separation columns slide automatically over the ends of the connecting tube. The connecting tube is sealed with metal disks instead of graphite ones. The flush gas conduits are so arranged that the dead spaces can be well flooded, reducing adsorption of sample and increasing the performance of the gas chromatograph.

Abstract: A metal gasket for a face-seal fitting has an outer section in the form of a circular annulus, an inner section in the form of a circular annulus and having a shorter axial dimension than the outer section. The inner section and outer sections are joined by a tapered section having conical faces on opposite sides thereof facing toward the axis of the gasket. A method of prolonging the useful life of a tubular element in a face seal fitting involves repeatedly engaging an end of the tubular element with the conical face and, when the end of the tubular element wears, engaging the end with a radial face adjacent to the conical face.

Abstract: A connecting member is disclosed for connecting a hydraulic tube to a base material such as a housing or to another hydraulic tube. The connecting member has an annular body formed from a first material extending a substantial length of the connecting member. The body has an interior surface defining a passageway. The body includes threads on a first portion of the body for connecting to the connecting member of a hydraulic tube and threads on a second portion of the body for connecting the connecting member to the base material or a second hydraulic tube through a coupling nut. A sleeve is made from a second material and extends through the passageway substantially the length of the connecting member. The sleeve has an internal surface and has a pair of ends, wherein each end of the sleeve extends radially outwardly from the sleeve relative to a central longitudinal axis of the sleeve over a respective end of the body. The body may be plastic and the sleeve may be titanium.

Abstract: A gas-tight end fitting for a tube, such as the type used in aircraft. The fitting has an internal annular groove extending partially into the fitting which forms an annular flange or beam, and the face of the beam and of the remaining portion of the fitting has a concave configuration of a single predetermined radius.

Abstract: The invention relates to a device for making a sealed connection of adaptable length suitable for interconnecting two pipes whose axes are not necessarily in alignment. The device in accordance with the invention comprises a flange placed on each pipe with each flange being provided with a spherical bearing surface on its end face and with a spherical bearing surface on its opposite face. A central tube has a thrust member mounted at each end thereof, each thrust member including a void for receiving at least one spacer. The tube is also provided with a flange which serves to bring the spacer against a sealing ring pressed against the end face of the flange by being clamped to a backing flange. The backing flange has a spherical surface that cooperates with the spherical surface of the opposite face of the pipe-mounted flange. At least one of said thrust members receives at least two spacers separated by sealing ring. The invention also provides a clamping method.

Abstract: A seal assembly for providing a primary metal-to-metal seal between the outer wall of a tubular member and the inner wall of a surrounding receiving bore slidingly receiving the tubular member. The sealing assembly includes a metal seal ring member having the general configuration of a toroid which has been flattened on its upper and lower surfaces. The metal seal ring member has a close fit on the outer wall of the tubular member, and an interference fit with the wall of the receiving bore. When stabbed into the receiving bore, the metal seal ring member coins onto the walls of the tubular member and the bore, resulting in an effective metal-to-metal seal. The seal assembly preferably includes a compliant seal ring member of a preferably high lubricity material, e.g., Teflon, disposed on the tubular member below the metal seal ring member.

Abstract: A pressure-balanced hydraulic coupling for use in undersea drilling and production operations, the coupling having radial passageways communicating between the male and female members such that substantial fluid pressure is not exerted against the face of either member during coupling or uncoupling or during the coupled state. Check valves in both the male and female members are opened when the male member probe is fully inserted into the receiving chamber of the female member. Mutually opposed valve stems extending from each check valve contact one another to effectuate the simultaneous opening of each check valve, and allow fluid to flow through a valve port and then radially through matching fluid passageways in the male and female members. The radial passageways of the male and female members match up at their longitudinal surfaces so that fluid pressure between the male and female members is in a substantially radial direction and is not exerted at the face of either member.

Abstract: Hermetic connection device comprising a double curve ductile joint (3) and two supports (1,2), the joint (3) being connected between the two supports (1,2) stressed towards each other along axis (8) and defining on one section of their thickness only two parallel surfaces (4,5) at an angle to axis (8), characterized in that in the normally clamped state the geometric characteristics of the supports (1,2) and of the joint (3) are such that contact between the joint (3) and the two supports (1,2) is made on the one hand through each inclined surface (4,5) respectively along a line of contact (9,10) and on the other hand by each extreme end of joint (3) supported against another surface (6,7) of the male support (1) or female support (2) respectively.

Abstract: An aseptic pipe joint for food processing pipe fittings of the type including a pair of frustoconical ferrules having radially extending surfaces, a "C" shaped metallic ring positioned between the surfaces in abutting relation therewith, a resilient O-ring filling the "C" shaped ring to form an aseptic seal, a resilient seal ring positioned between the ferrule surfaces and spaced radially outwardly from the "C" shaped ring forming a hermetic zone between the seals and a passage in one of the ferrules connected to the hermetic zone for testing the aseptic seal.

Abstract: A packoff assembly for sealing an annulus between an inner tubular member and an outer tubular member including a sealing means rotatably connected to a packing nut. The sealing means includes an upper actuation ring rotatably retained on the packing nut. A sealing member having a ring-like metal body is rotatably mounted on the upper actuation ring with a roller ball connection which permits limited relative axial movement between the upper actuation ring and the sealing member. A lower actuation ring is rotatably mounted on the body of the sealing member by another roller ball connection which permits limited relative axial movement between the lower actuation ring and the body of the sealing member. The metal body of the sealing member includes a pair of frustoconical-shaped outer seal lips and a pair of frustoconical-shaped inner seal lips. An elastomeric seal ring is disposed on the body of the sealing member between each pair of metal seal lips.

Abstract: A nut adapter to be formed to hardly twist a pipe welded to a cap nut clamping fluid joint or eliminate the twist of the pipe when clamping the cap nut of the fluid joint, and a fluid joint having the nut. This nut holds a thrust bearing at a position of the nut, corresponding to the surface of the nut for pressing a sleeve when clamping the nut so that, when an unreasonable force is applied, the nut and the sleeve rotate together so as not to transmit a rotary torque to the pipe.

Abstract: A hydraulic connector for a subsea well assembly has spherical hydraulic seats. Each seat has the same radius of curvature in a vertical direction as in a horizontal direction. Each connector member has a plurality of hydraulic passages, each hydraulic passage having a port terminating at the hydraulic seat. The ports of one of the connector members register with the ports of the other connector member. A counterbore is located at the port of each hydraulic passage of the one connector member, defining a recessed base. A seal element is located in each counterbore. The seal element is frusto-conical and is formed of a plurality of conical metal and elastomer laminations alternating with each other.

Abstract: A tubular connection having a nose extension on the pin member for stiffening the member and exhancing the conical seal area forward of the first thread, which seal is spaced at a distance from the time end by a non-sealing nose extension that is at least as long as the sealing area. The integrity of the seal is improved, the bearing surface is enlarged and the tendency of galling is reduced.

Abstract: A joint for rigidly coupling first and second pipes having high temperature fluid flowing therethrough. The joint comprises first and second annular members including mating spherical segments which are rigidly coupled, respectively, to the pipes; a coupling assembly to couple the annular members in telescoped engagement and to radially inwardly compress these members to resist relative angular movement therebetween; an annular cavity defined by the telescoped annular members and communicating with the interface of the engaged annular members; and an annular, metallic and torsionally flexible seal located in the cavity to resist fluid escape from the joint through the interface of the annular members. The joint accepts annular misalignment of the pipes as the pipes are being connected, but thereafter the coupling assembly applies the radially inwardly directed compression to the mating spherical segments to resist further relative angular movement therebetween.

Abstract: A swivelable quick connect assembly for transferring of high-temperature, low-pressure fluids is disclosed as comprising a device having an axial bore for receiving one end of a conduit, a retaining element being demountably coupled to the device in the axial bore, the retaining element having a securing portion for securely fastening the conduit in the retainer element, a device engaging portion for retaining the retainer element in the axial bore of the device and the retainer having a sealing element with a concentric ring design for effecting a seal between the device and the conduit.

Abstract: A sealing ring, having a ring body made, for example, of high-temperature resistant compressed metal fibers includes a roughened surface adapted to be pressed against and displaced by sliding relative to a counter-face.

Abstract: To connect two pipes which may carry high-temperature potentially corrosive fluids, for example exhaust gases from an internal combustion engine, while permitting flexing of the pipes with respect to each other in torsion or twist, bending or lateral shift, while maintaining a sealed connection, a ring chamber is formed in the region of the pipe ends, by an overlapping pipe end portion of the like, an external sleeve, or overlapping flange construction, which retains therein a sealing and support pillow of ceramic or metal materials in form of fibers, filaments or the like, felted, matted, woven, knitted and compressed together; a metal sealing foil, for example of aluminum or specialty steel, crinkled or creased and preferably formed with expansion/contraction undulations, is located within the pillow.

Abstract: A bi-directional metal-to-metal seal (10) comprising a ring with a pair of oppositely acting sealing elements (20 or 22) integral with the outer periphery of the ring. In one embodiment, two pairs of such sealing elements (20 and 22) are located on each end of the ring (as viewed in cross section) and are of a thickness to be resilient (springy) and deflectable when inserted in an interference fit relationship into a cylindrical wall or bore to be sealed. The first sealing element (24) has a curved outer surface (26) and with an opening (30) facing the main flow path of pressure fluid. The curved outer surface rolls inward against the cylindrical wall (42) while being inserted into the cylinder, partially closing the opening (30) but still allowing the pressure fluid to enter and urge the curved surface against the cylindrical wall.

Abstract: A seal system between two metal pipes (1, 2) flanges (4, 5) exposed to extreme temperatures, includes at least one elastic annular lip (11, 12) which is held by one of the flanges, with its highest point (10) in contact with the other flange to form a seal line when the flanges are assembled. The lip (11, 12) is an integral part of one of the flanges (4, 5) and it is made by lathing two grooves (13, 14; 17, 18) with one groove (13, 17) radially penetrating the cylindrical surface (15, 19) of the flange, and the other groove penetrating perpendicularly to the former in the flat surface (7, 8) of the flange to define a thinned area (16, 20) between the two grooves to ensure the elasticity of the lip (11, 12).

Abstract: A joint for connecting first and second co-axial pipes each having inner and outer pipes with a male joint portion receiving the pipes of one co-axial pipe and a female joint portion receiving the pipes of the other co-axial pipe. The end surfaces of the two portions have opposed protrusions which sealing engage a metallic packing.

Abstract: A coupling and metal seal are disclosed, primarily for use in undersea hydraulic applications. The female member of the coupling is of three-piece construction. The main body portion accepts a cylindrical retainer which is held captive within the body by means of a spring clip or snap ring. The metal seal is generally ring-shaped and is positioned within the body and held captive by the retainer and clip. The male member, or probe, of the coupling fits within the retainer and body and protrudes through the ring of the metal seal. The seal engages the circumference of the probe and, when the coupling is pressurized, the seal is urged against the probe circumference and against the interior wall of the body, effectuating a fluid seal within the coupling. The metal seal is not irrevocably deformed in use and may be used repeatedly.

Abstract: A connection for preventing relative movement between coupled members in a clamped joint. The coupled members are connected across a shear member which transfers shear forces from one member to the other. Each coupled member has a roughened surface with a 500 to 1000 microinch arithmetic average finish providing protrusions which embed into the shear member and allow positive load transfer without slippage. This shear member is made of a material having a lower resistance to plastic deformation than either of the coupled members. Clamping of the joint provides the necessary force for embedding the roughened surface of the coupled members into the shear member. The simplicity and low cost of this connection makes it particularly useful for a wide variety of bolted assemblies.

Abstract: A superfine finish piping joint has a metal C ring disposed between a couple of joint pieces, the piping joints being capable of properly tightening the metal C ring for thereby being usuable for piping to a clean room. The superfine finish piping joint includes, besides a couple of the first and second joint pieces, a box nut, a thrust bearing disposed between a base portion of second joint piece facing to the internal end surface of an box nut, and a cup-shaped retainer serving to mount balls and rings, etc., of the thrust bearing as a whole on the second joint piece, etc., at prescribed positions.

Abstract: Seal means for reducing the gas flow through the space between the opposing ends of first and second concentric axially disposed cylinders is disclosed. The seal means includes a presizeable annular leaf seal concentrically mateable with the first cylinder. In addition, the seal means includes securing means for securing the left seal to the second cylinder. In a specific embodiment, the seal means provides an effective seal between a turbine rear frame and mixer liner.

Abstract: A mounting for an object processed at a predetermined temperature in an uahigh vacuum chamber having a stainless steel wall. The mounting has a stainless steel tube welded to the wall and opening through it and has an oxygen-free-high-conductivity copper finger extended from the tube to receive the object. At the junction of the tube and the finger, the tube bears an annular knife edge which engages a flat surface of the finger, and an ultrahigh vacuum seal is established by a collar and bolt coupling which draws the finger against the knife edge. The temperature of the finger and the object are then controlled and measured by cryogenic liquids, electrical heaters, and sensors inserted through the tube into contact with the finger.

Abstract: A metallic spring member 30 cooperates with grooves 32, 34 disposed in pressure containing members 10, 12. The spring member 30 has an E-shaped cross section and is compressed both horizontally and vertically when the members 10, 12 are fully engaged. The seal is self-energizing under normal operating conditions and able to accommodate small, but significant relative motion between the pressure containing members 10, 12 during conditions of abnormally high and unevenly distributed temperature.