Patent Description:
<CIT> teaches an insulated steam injection tubing string for conveying vapors.

<CIT> mentions a double-walled pipe with integrated heating capability for an aircraft or spacecraft.

<CIT> relates to a shut-off valve, in particular a ball valve, consisting of a housing with two connection ends for lines, a movable shut-off device in the housing with an outwardly guided actuator and an electrically insulating insert in the area of at least one connection end.

Fluid flow devices (e.g., pipes, valves, nozzles and the like) subjected to thermal shocks in severe industrial applications can benefit from thermal protection to reduce thermal stresses, mitigate the effects of thermal shock experienced and prevent premature thermal fatigue. Fluid flow devices subject to cyclic high pressure and temperature changes make them prone to failure due to thermal shock. Thermal shock refers to a process wherein the flow device experiences sudden large magnitude changes in thermal stress when the heat flux and temperature gradient experienced by the flow device change abruptly.

Thermal shock damage can be found in various severe service industries (e.g., in a catalyst injection valve and its connection pipes in an ebullated bed hydro-processing ore refining application). In the case of an ebullated bed hydro-processing system, for instance, cracking of valve body and metal valve seats has been observed when valves are exposed to temperatures and pressures of up to <NUM> (<NUM> °F) and <NUM> MPa (<NUM>,<NUM> psi) at <NUM>-<NUM> cycles per day. Cracking is thought to occur due to initial thermal stresses experienced when the valve is opened to experience such high temperature and pressure after several hours of having remained closed and therefore having reached ambient temperature. This phenomenon is especially observed during winter when external ambient temperature drops (e.g., to as low as -<NUM> (-<NUM> °F)) and pre-heating systems fail.

Over the years, several innovations have been presented to help mitigate the effects of temperature surges and, in some cases, proposed solutions have been adopted. Some of the attempted solutions currently in use include use of materials having low thermal conductivity, use of pre-heating systems, use of thermal barrier coatings which are highly refractive, etc. While these attempted solutions have achieved some level of success, they continue to present shortcomings which are here addressed by several example embodiments of improved thermal insulating sleeve liners for fluid flow devices used in severe industrial applications.

Pre-heating systems have proven to be unreliable. There are reported cases where pre-heating systems malfunctioned and resulted in valve operations being carried out without pre-heating. Cracking of the valve body is especially observed when this occurs, and regular maintenance is required to avoid such incidents. This may be costly but even then normal operation is not guaranteed, especially during harsh weather conditions.

Adoption of low thermal conductivity materials has been proven not as effective since cracking could still be observed on the bodies of flow devices. This is a clear indication of their susceptibility to extreme cyclic temperatures. This led to the adoption of thermal barrier coatings (TBCs). While TBCs have generally been more effective in providing thermal shock protection, they too have several limitations. TBCs are susceptible to erosion and corrosion, especially in instances where they are in the flow path. TBCs require laborious and expensive processes for their preparation which results in high initial costs. And TBCs are notoriously brittle and prone to corrosion and erosion. Sleeves with TBCs need to be frequently replaced.

Some non-exhaustive examples of prior thermally insulating sleeve liners or other thermally protective internal interfaces for fluid flow devices can be found, for example, in the following prior published US patent documents:<CIT>; <CIT>; <CIT>; and <CIT>.

The present document describes an improved, preferably additively manufactured (by 3D printing), thermal insulating sleeve liner constructed of a nickel-alloy material for the serviced application (e.g., Inconel <NUM>® or other austenitic nickel-chromium-based super-alloys, high nickel alloys and the like) with an internal infill structural pattern creating internal voids which increase thermal insulation properties while yet remaining structurally adequate to serve as a thermal insulating flow device liner for the serviced application. Preferably the infill is sized to maximize strength (i.e., to support internal/external pressures to be experienced by the sleeve) while concurrently also minimizing heat transfer (i.e., from the inside to the outside of the sleeve). Multi-layer material could also be used if the sleeve is made with wear-resistant, corrosion-resistant, low thermal conductivity materials. When a 3D printed sleeve comes out of the printer, it is in a green state. Subsequently parts can be subjected to hot isostatic pressing (sometimes referred to as being "hipped") and/or heat treated to reduce porosity and increase mechanical properties respectively. Based on testing, all these three states are believed to work.

An object of example embodiments described herein is to provide a thermal protection device with varying designs based on the method of manufacture and intended application.

In one example embodiment, an additively manufactured (3D printed) thermal sleeve includes two spaced-apart cylindrical shells and an internal infill pattern of integrally-formed supporting structure there-between. This thermally insulating sleeve is fitted into the flow path of the protected flow device (e.g., valves, pipes and the like). The sleeve could be locked by an interference fit with the body. Other locking methods such as brazing, welding or one or more retaining rings could be considered as well. The infill may have variable patterns that may be in the form of, but not limited to, centroidally-directed lattices, hollow honeycomb-like structures and so forth. These patterns form a porous network of supporting structure containing voids between the two shells. This network of structure entraps air (or other insulating material such as an inert nitrogen gas or an insulating vacuum) thus allowing for heavy internal insulation of flow devices to prevent or reduce thermal shock therein. Tessellations or other structural patterns inside the sleeve allow for free design of infill percentage making it customizable depending on process requirements and parameters. The end of the sleeve may be left open or fused. For sleeves having fused ends, the air-tight infill patterned region or chamber can be vacuumed or pressurized (e.g., with air or an inert gas).

In another example embodiment, a pressure equilibrium hole can be made on or through the sleeve. While the sleeve can remain acting as if a solid air-tight structure, the pressure equilibrium hole ensures a pressure balance between its inner and outer surfaces.

In another example embodiment, a non-encapsulated thermal sleeve is slip-fitted into a flow device bore. This sleeve can have variable exterior protruding surface patterns which can change depending on process requirements. Examples of these may include axially ribbed or radially ribbed exterior protruding surface patterns. Exterior surface patterns reduce the surface area in thermal contact with the interior bore body of the flow device while still allowing air entrapment there-within. This device is preferably additively manufactured (by 3D printing). Depending on the application, the thermal sleeve may have a wear and abrasion resistant layer on its inner surface. Such functional graded layers can be deposited either by conventional deposition methods (such as a spray of thermal material) or by additive manufacturing (i.e., 3D printing) processes.

For an example embodiment installed in a flow device, the different sleeve concepts may be capped (e.g., using a separate circumferential ring-shaped cap structure) or they may have an integrally-formed circumferential ring-shaped lip in other embodiments to secure and/or locate the sleeve within the flow device. The lipped sleeve may be produced as a single piece while the capped sleeve has two distinct parts: the main sleeve part and the securing cap part. The lip or cap can interact with a larger diameter bore section at a proximal end of the main sleeve part and a narrower diameter bore section at the other distal end of the main sleeve part (so as to locate and trap the main sleeve part at a desired location within the flow device bore). The cap may be of the same material as the sleeve or of the same or similar material as the flow device. The securing cap can be welded to the flow device on the proximal larger diameter bore section after the main sleeve part has been snug-fit into a main bore length against the end face of a smaller diameter distal bore section thus retaining the main sleeve part at a desired location. The lip of a lipped sleeve, if that is used instead of a separate cap ring, can be similarly welded directly to the body of the flow device at the larger diameter proximal bore section to retain the sleeve at a desired location.

Some example embodiments of an improved additively manufactured thermal insulating sleeve liner are sized to have an outside dimension and surface area purposefully smaller than the inside dimension and surface area of the protected flow device, thereby reducing sleeve liner thermal contact with the protected flow device and thus enhancing its thermal protection. Dimensions should provide the loosest possible fit so long as it does not permit or cause excessive vibration or permit ingress of thermally conductive material in use. In some embodiments, a loose fit clearance of a few thousands of an inch (e.g., on the order of <NUM> (<NUM> inch)) may be suitable.

Some example embodiments of the improved additively manufactured thermal insulating sleeve liner may include spaced-apart external (i.e., outwardly protruding) structures to insure less thermal contact with the internal surface of a protected flow device thus further reducing sleeve liner thermal contact with the protected flow device and enhancing its thermal protection.

Some example embodiments of the improved additively manufactured thermal insulating sleeve liner may include an integrally formed larger diameter lip at one end to assist in locating and/or retaining the sleeve liner properly within the protected flow device. Such a locating/retaining end lip (e.g., a diameter larger than the main sleeve liner body to retain a respectively associated end at a proper location in use) may also be formed as a separate retaining cap-ring structure that is secured (e.g., by a few tack or seal welds) at a proper location within the protected flow device.

Some example embodiments of the improved additively manufactured thermal insulating sleeve liner are installed within a protected flow device so as to provide an integrated flow device product incorporating the improved thermal insulating sleeve. However in use, due to wear and/or other deterioration in use, it will likely be necessary to periodically remove the thermal insulating sleeve (e.g., by breaking spot or seal welds holding it in place) and replace it with a new or refurbished thermal insulating sleeve. And if a flow device is not initially provided with the improved additively manufactured thermal insulating sleeve, then one can be retrofitted into the flow device to thereafter provide desired thermal protection.

The improved additively manufactured thermal insulating sleeve liner is preferably constructed so as to prevent ingress of thermally conductive materials (e.g., catalyst particles which may typically be on the order of <NUM> - <NUM> in diameter with nickel-molybdenum active metal catalysts) into internal voids of the insulating sleeve or between the outer sleeve surface and the internal surface of the protected flow device. In this way the thermal insulating and protective properties of the sleeve can be better maintained. At the same time, some pressure equalization may be needed, at least in some applications, between the inside and outside surfaces of the insulating sleeve (perhaps including internal voids of the sleeve). If a pressure equalization path is needed, care should be taken to keep the pressure equalization path(s) small enough to prevent ingress of flowing thermally conductive particles (e.g., metallic catalyst particles).

Some example embodiments of the additively manufactured thermal insulating sleeve liner have two solid shells sandwiching a concurrently formed additively manufactured infill pattern (i.e., manufactured by a conventional 3D printing process). The infill pattern may vary and may range from simple honeycomb structures to complex lattice structures depending on process requirements and parameters. The sleeve may have an open end, or the ends may be fused to make the sleeve airtight. In the case of an airtight sleeve, the infill pattern chamber voids may be vacuumed or pressurized.

Some example embodiments of the additively manufactured thermal insulating sleeve liner are non-encapsulated with variable patterns on the external sleeve surface that may be modified depending on the application.

Some example embodiments of the additively manufactured thermal insulating sleeve liner have a wear-resistant coating along the axial flow way.

Some example embodiments of the additively manufactured thermal insulating sleeve liner are trapped via a separate retaining cap or have an integral lip which in either case is welded to one end of the bore to be protected on the flow device (e.g., with spot welds or seal welds that can be easily broken when it is desired to remove/replace a previously installed insulating sleeve).

The example embodiments described herein offer several advantages. The additively manufactured (3D printed) thermal insulating sleeve device is produced in one manufacturing step resulting in considerable savings. It requires little lead time as the design process is much shorter than other manufacturing methods. Validation of the parts can commence as soon as the part is printed. Since the device can be additively manufactured, unique and more complex structures can be made for the infill without interfering with sleeve integrity. Additionally, there is very little material wasted in an additive manufacturing process and a homogeneous density of the resulting insulating sleeve ensures a more evenly distributed sleeve strength.

To reduce the laborious procedure that would involve dis-assembly of the protected flow device during part replacement or planned plant maintenance, the present example embodiments are designed to be easily replaceable upon reaching the end of design life. This can be done by removing the flow device from the process and sliding the loosely fit sleeve out of the flow device bore (after light holding spot or seal welds are broken). Additionally, toughness of the material involved will ensure that the sleeve is more robust than in the past thus ensuring, among other things, less scrap and a potential for the sleeve material to be re-used.

The accompanying drawings depict various example embodiments for illustrative purposes but are not to be construed as limiting the scope of later appended claims.

In the accompanying drawings identical reference numerals may have been used to identify features which are identical or similar in function. The example embodiments demonstrate varied designs based on similar concepts to provide an overall view of example thermal insulating sleeve liner interactions with flow devices.

<FIG> is a schematic isometric general overview of a thermal insulating sleeve <NUM> having an inner shell <NUM>, outer shell <NUM>, an infill pattern <NUM> of supporting structure with included voids provided between the inner and outer shells <NUM>, <NUM>, and open ends <NUM> (e.g., see <FIG>). The material and infill pattern <NUM> of the thermal sleeve can be varied to offer different strengths and thermal insulation depending on the application for which it is intended. As those in the art will appreciate, a typical ebullated bed hydro-processing application flow device conveys a corrosive liquid carrying small (e.g., <NUM> - <NUM> diameter) titanium catalyst particles at temperatures on the order of <NUM> - <NUM> (<NUM> - <NUM>,<NUM> °F) at a pressure on the order of <NUM> MPa (<NUM>,<NUM> psi). In this application, as those in the art will appreciate, a thermal insulating sleeve liner could typically be made of a tungsten alloy. As those in the art will recognize, the material and structure of the thermal insulating sleeve liner must be chosen appropriately in accordance with conventional standard design practices to accommodate process parameters of the application being serviced. Such sleeve characteristics are typically determined by the extreme pressures and temperatures to which the sleeve will be subjected. The thermally insulating sleeve liner <NUM> can be slip-fit into a flow device bore. The open ends <NUM> should be fitted to mating internal surfaces of the flow device sufficiently closely to make it impossible for solid entrapment (e.g., of metallic thermally conductive catalyst particles) within the chamber of the infill pattern <NUM> or between the outer shell <NUM> and the inner surfaces of the flow device.

Complex lattice infill patterns <NUM> provide a longer and indirect path for thermal conduction while air (or other insulating material or vacuum) trapped in between the two shells due to interstices of the infill pattern <NUM> possesses poor thermal conduction properties leading to increased thermal insulation.

<FIG> is a schematic isometric general overview of a thermal insulating sleeve <NUM> having an inner shell <NUM>, outer shell <NUM>, an infill pattern <NUM> of supporting structure with included interstice voids provided between the inner and outer shells <NUM>, <NUM>, and fused ends <NUM> (i.e., closed ends <NUM> as depicted in <FIG> so as to encapsulate the voids included within the infill structure <NUM> between shells <NUM>, <NUM> and ends <NUM>). As with the thermal sleeve <NUM> of <FIG>, the material and infill pattern <NUM> of the thermal sleeve <NUM> can be varied to offer different strengths and thermal insulation depending on the application for which it is intended. Here the voids within the chamber containing infill pattern <NUM> can be vacuumed or pressurized before ends <NUM> are fused shut (e.g., one end can be left partially open and connected to a source of vacuum or pressurized thermally insulating gas or liquid fluid before this partial opening is also fused to a fully closed configuration). Once the voids are thus suitably treated and the ends <NUM> fused to a closed state, the thermally insulating sleeve liner <NUM> can be slip-fit into a flow device bore. The fused closed ends <NUM> make it impossible for solid entrapment (e.g., of metallic thermally conductive catalyst particles) within the chamber of the infill pattern <NUM>. The fused ends <NUM> should be fitted to mating internal surfaces of the flow device sufficiently closely to make it impossible for solid entrapment (e.g., of metallic thermally conductive catalyst particles) between the outer shell <NUM> and the inner surfaces of the flow device.

While some prior art thermally insulating sleeve liners have been shrink-fitted into tight engagement with the internal walls of the flow device, it is preferred to only loosely slip-fit the thermally insulating sleeve liner <NUM> or <NUM> within the internal bore walls of the flow device so as to provide additional thermal insulation between a hot corrosive high pressure flowing substance and the flow device structures.

<FIG> depict the example thermal insulating sleeves <NUM> and <NUM>, respectively, with an included securing cap or lip <NUM> at one end. A securing cap may be separately constructed and fitted at an end of the sleeve when installed within a flow device to secure it at a proper location in use within a flow device. A securing lip may be constructed as an integral part of the sleeve at an end to secure it at a proper location in use within a flow device.

<FIG> depicts an example capped radially-ribbed thermally insulating sleeve liner <NUM>. The externally extending interstices between ribs <NUM> will provide additional thermally insulating spaces when fitted within the internal surfaces of a flow device bore. Example sleeve liner <NUM> is preferably created by additive manufacturing (3D printing) to provide a central portion of the sleeve body between inner and outer shells with an infill pattern as in the examples of <FIG>, <FIG> to provide still further thermal insulation as in these earlier-described embodiments. The section cut highlights an end contact between the sleeve <NUM> and a separate securing cap <NUM> (which functions, like the securing cap of earlier-described embodiments). As those in the art will recognize, the securing cap <NUM> could be replaced by an integrally manufactured securing/locating lip if desired (as depicted in <FIG>).

<FIG> depicts an example lipped axially-ribbed thermally insulating sleeve liner <NUM>. The externally extending interstices between ribs <NUM> provide thermally insulating spaces when fitted within the internal surfaces of a flow device bore. Example sleeve liner <NUM> is preferably created by additive manufacturing (3D printing) to provide a central portion of the sleeve body between inner and outer shells with an infill pattern as in the examples of <FIG>, <FIG> to provide still further thermal insulation as in these earlier-described embodiments. The section cut highlights the integrally formed securing/locating lip <NUM> formed at an end of the sleeve <NUM> (which functions, like the locating/securing lip of earlier-described embodiments). As those in the art will recognize, the locating/securing lip <NUM> could be replaced by a separate securing/locating cap if desired (as depicted in <FIG>).

When disposed about an axial flow passage within a flow device bore (e.g., as shown in <FIG>), the externally ribbed sleeve <NUM> or <NUM> makes less surface contact with the flow device bores due to the surface pattern of ribs on its exterior thereby reducing thermal stress concentration points.

While <FIG> illustrate two options of radially-ribbed and axially ribbed exterior surfaces, as those in the art will appreciate, the ribbed pattern can be modified as desired to accommodate requirements of various processes.

<FIG> and <NUM>-<NUM> depict a capped thermal protection sleeve <NUM> installed in a flow device <NUM>. The thermally insulating sleeve <NUM> (of any example embodiment described herein) can be disposed in a flow device (e.g., flanged pipe <NUM>) detachably connectable to other flow devices (e.g., valves). The interaction between the sleeve <NUM> and the pipe <NUM> is like that between an example sleeve and the internal flow surfaces of other flow devices (e.g., valves). The example thermally insulating sleeve <NUM> is slip-fitted into a bore of the pipe body that has a smaller diameter end portion locating and closing (if the sleeve does not already have a closed end) one end of the sleeve <NUM> to the ingress of flowing thermally conducting materials in use. A securing cap <NUM>, disposed within a larger diameter end portion of the flow device bore, secures and locates the other end of the thermal insulating sleeve <NUM> within the flow device bore (and closes it to ingress of flowing thermally conducting materials in use if the sleeve does not already have a closed end).

<FIG> depicts lipped thermal protective sleeves <NUM>, <NUM> slip fitted into flanged pipe input/output ports of a valve <NUM>. In an enlarged partial section view depicted at <FIG>, the outer surfaces of integral securing/locating lip <NUM> of sleeve <NUM> is mated to a larger diameter proximal internal bore section <NUM> while the main body of sleeve <NUM> is slip-fit into the relatively narrower main bore <NUM> of the flow device valve <NUM> - and the other end of sleeve <NUM> is butted to a narrower diameter distal bore section. The lip <NUM> is held in place during use by weld(s) <NUM> (e.g., spot or seal welds that can be easily broken when it is desired to remove/replace the sleeve <NUM>).

As those in the art should now appreciate, the general installation overview of <FIG> also can be used for a capped thermal protective sleeve (with open or fused ends and a separate locating/securing cap at the proximal end). As such, the arrangement of <FIG> can be used for all lipped or capped sleeve example embodiments. This includes the radially ribbed, axially ribbed, the in-filled lattice sleeves of <FIG>, <FIG> and so forth whether capped or lipped.

<FIG> illustrates capped thermal protective sleeves <NUM>, <NUM> slip fitted within the bores of a flow device (e.g., the flanged input/output pipes of a valve <NUM>). Like the lipped sleeve of <FIG>, this arrangement applies in general to all example thermally insulating sleeves. The sleeves <NUM>, <NUM> are fitted into the flow device <NUM> just like sleeves <NUM>, <NUM> are fitted into the flow device <NUM>. However, as depicted in the enlarged view at <FIG>, since a separate securing cap <NUM> is now employed (instead of the integral lip <NUM> in <FIG>), the securing cap <NUM> is held in place during use by weld(s) <NUM> (e.g., spot or seal welds that can be easily broken) while the distal other end of a sleeve is located against a smaller diameter bore section at the opposite distal end of the flow device bore (with a sufficiently small clearance fit to prevent ingress of thermally conductive material during use). This arrangement holds for all capped or lipped sleeve example embodiments. This includes the radially ribbed, axially ribbed, the in-filled lattice sleeves of <FIG>, <FIG> and so forth whether capped or lipped.

<FIG> is a cut-away schematic isometric view of valve <NUM> in <FIG> showing sleeve <NUM> having its distal end butted to a smaller diameter distal end <NUM> of flow device bore <NUM> and trapped there by the larger diameter cap <NUM> within larger diameter proximal bore <NUM> by weld(s) <NUM>.

To establish some measure of efficiency for an example embodiment, a <NUM>-dimensional finite element analysis using a transient thermal technique was conducted for a ball valve having a flanged end connector inside diameter of <NUM>,<NUM> (<NUM> inches) and an outside diameter of <NUM> inches, subjected to extreme temperature and pressure cycles between <NUM> (<NUM> °F) and <NUM> MPa (<NUM>,<NUM> psi) respectively. Three different setups were used: the flow device without any thermal protective device; the flow device with the internal surface that interacts with the axial flow path coated with thermal and wear resistant materials; and the flow device with a thermal protective sleeve as shown in <FIG>. The thermal protective sleeve was made of Inconel <NUM>® by conventional 3D printing processes.

Peak stress intensities in the end connectors was found to be <NUM> MPa for the flow device without any thermal protective technology, <NUM> MPa for the model with the thermal and wear-resistant coatings and <NUM> MPa for the model with a thermal protective sleeve of the type described herein. This translates to a design life of <NUM>,<NUM> cycles, <NUM>,<NUM> cycles and <NUM>,<NUM> cycles respectively from fatigue design curves using fatigue analysis based on American Society of Mechanical Engineers (ASME) criteria (i.e., ASME <NUM> Boiler & Pressure Vessel Code Section II Part D and Section III A were used for the fatigue analysis).

According to the invention, the thermally insulating sleeve is additively manufactured by 3D printing, constructed of a nickel alloy material with an internal infill structural pattern creating internal voids which increase thermal insulation properties while yet remaining structurally adequate to serve as a thermal insulating flow device liner for the serviced application. Preferably the infill is sized to maximize strength (i.e., to support internal/external pressures to be experienced by the sleeve) while concurrently also minimizing heat transfer (i.e., from the inside to the outside of the sleeve). Multi-layer material could also be used if the sleeve is made with wear-resistant, corrosion-resistant, low thermal conductivity materials. When a 3D printed sleeve comes out of the printer, it is in a green state. Subsequently parts can be subjected to hot isostatic pressing (sometimes referred to as being "hipped") and/or heat treated to reduce porosity and increase mechanical properties respectively. Based on testing, all these three states are believed to work.

Depending on the application, the interior surface of the example embodiments may be sprayed with a suitable wear-resistant coating as those in the art will appreciate.

The functionality of the example embodiments is not limited to any particular flow device as those in the art will appreciate.

Example thermal insulating sleeve liners for a fluid flow device provide a loosely-fit additively manufactured thermal protective sleeve disposed axially in bores of flow devices such valves and pipes. The sleeve may have variable designs depending on applications and may include, but are not limited to: (a) a sleeve made of an internal shell, an outer shell and an infill pattern; (b) a sleeve with radial ridges; (c) a sleeve that is ribbed axially - and wherein the infill lattice structures and exterior surface patterns may be modified to meet process parameters. Any of these examples may be lipped or capped depending on the preferred arrangement and/or weld.

An example thermal insulating sleeve liner structure having an internal shell, an outer shell and fused ends may have an airtight vacuumed infill chamber.

An example flow device fitted with an example thermal insulating sleeve liner may have an internal shell, an outer shell an infill chamber there-between with fused ends and a pressure equilibrium hole there-through.

An example thermal insulating sleeve liner structure may have an internal shell, outer shell, a pressurized infill chamber and seal-welded ends.

The thermal insulating sleeve liner structure is made of a high nickel alloy.

An example thermal insulating sleeve liner structure may have a wear-resistant coating on its inner surface of an internal shell.

An example thermal insulating sleeve liner structure may use a securing cap which may or may not be of the same material as the body of the flow device to which it is welded within a bore of the flow device. Alternatively, the securing cap may be threaded for a threaded connection with the bore of a flow device.

Claim 1:
A thermal insulating sleeve liner (<NUM>) configured for use in a fluid flow device subjected to cyclic extreme thermal shock, said configured thermal insulating sleeve liner (<NUM>) comprising:
a hollow cylindrical sleeve (<NUM>) having an outer diameter sized to slide into a fluid flow path bore of a fluid flow device thereafter accommodating a fluid flow path there-within, said sleeve (<NUM>) having two spaced-apart cylindrical shells (<NUM>, <NUM>) , characterized in that the hollow cylindrical sleeve is 3D printed and in that said sleeve has an internal infill pattern (<NUM>) of integrally formed supporting structure there-between including internal interstices providing increased thermal resistance to heat flowing from inside the sleeve (<NUM>) to outside the sleeve (<NUM>) , wherein said sleeve liner (<NUM>) is made of a nickel alloy material.