SLIDE VALVE

Abstract: Disclosed is a slide valve (10) for high temperature and/or abrasive service, wherein a lining (12) of refractory material is securely cast to and supported by the inner surface of an outer metal shell to form a body having a flowway (13) therethrough with an inlet (14) and an outlet (15) having side opening (17) intersecting the flowway intermediate the inlet and outlet. Grooves (20) are formed in opposite sides of the flowway (13) with each groove providing or including a downstream guide surface (21) and an upstream guide surface (22) which surrounds an orifice (19) at the intersection of the inlet with the flowway. A slide (23) is movable through the side opening into and out of positions in which its opposite side edges are received between the guide surfaces of the grooves for guided reciprocation between positions controlling flow through the flowway. The refractory material has sufficiently high compressive strength to carry the load of the slide. Wear prone parts, such as replaceable inlet and outlet liner segments (18a, 21a), replaceable guides or guide assemblies (66) are provided which are aligned and locked in place by the slide. All wear prone parts are removable and replaceable through the bonnet without removing the valve from the line.

Description: Slide Valve Technical Field This invention relates generally to a slide control valve for high temperature and/or abrasive service, such as used in oil refineries. More particularly, it relates to an improved valve of this type having a body which includes an outer metal shell which is lined with refractory material. Background Art As described in U.S. Patent No. 3,726,306, slide control valves of this type are generally quite large having internal diameters ranging in size from eighteen inches (18") to eight feet (8 1 ). Due to the services in which they are used, it is often necessary to repair or replace their internal parts including the slide. Obviously, it is desirable that this be done without taking the valve body out of the flow line in which it is installed. In use the slide of a valve of this type normally occupies a throttling position and is opened or closed depending on the type of valve or service during start up and in the event of an emergency. Since flow through the valve is normally in a vertical direction, the slide must be supported in the valve body; and due to the size of the slide and the impingement of the flow on the slide, which partially closes the valve orifice, this vertical positioning of the valve imposes considerable load on the structure in the valve body on which the slide is supported. Consequently, there is a need to guide the slide as it is moved between its flow controlling positions. In the aforementioned patent, the side edges of the slide are guidably reciprocable within guides secured to a seat ring or orifice plate on the body of the valve. The slide, guides and orifice plate are preassembled to permit them to be moved as a unit through a side opening in the body of the valve and then secured thereto to dispose the orifice in alignment with the flowway in order to smooth out turbulent flow through the valve. As explained in such patent, this structure not only permits the installation and removal of the internal parts as unit, but also minimizes distortion, binding and wear by maintaining tolerances between the internal parts and the valve body due to thermal and mechanical stress. In valves of this type where the slide is normally in throttling position, it is not necessary to maintain a tight seal between the slide and the seat surrounding the orifice in the orifice plate. The slide has a T-slot connection with the stem of an actuator mounted on a bonnet removably installed on the body over the side opening whereby the slide is free to shift into tight, load bearing engagement with the downstream guide surfaces. In valves of this type manufactured and sold by Tapco, a division of Triten Corporation of Houston, Texas, the outer metal body is lined with a refractory material. Alternatively, the valve body may be lined with insulating material and the latter lined with refractory material. This results in a so-called "cold shell" design wherein external body temperatures are minimized. Although these valves have experienced considerable success, they nevertheless require the fabrication of a large number of internal parts and considerable time and effort involved in assembling and disassembling them for repairs and replacement. The time and the cost involved in fabricating valves such as the type shown in the above-identified patent are significant. These costs are multiplied in the case of valves having larger internal diameters in large part because of the difficulties in maintaining precise tolerances across large diameters. These costs are further increased by valves such as a diverter valve having, for instance, a ninety-six inch (96") inlet diameter and two side-by-side outlets each having an internal diameter of ninety-six inches (96") such that the guides must be at least sixteen feet (16') long plus the distance the outlets are spaced apart. It would be highly desirable and advantageous to provide a valve of this type lined with a refractory material which bears the load so that the wear prone parts can be readily and easily removed, repaired or replaced through the bonnet without disassembling or removing the valve from the flow line. The present invention is directed to such a valve. Disclosure of the Invention The slide valve according to the present invention has a refractory material securely cast to an inner shell, which refractory material has high compressive strength sufficient to carry the load through the valve. The refractory material has a flowway therethrough with an inlet and an outlet, removable and replaceable inlet and outer liner segments secured to the refractory material at wear prone portions of the flowway and a side opening intersecting the flowway having grooves formed in opposite sides thereof into which grooves is placed a removable and replaceable guide assembly or guides having at least a downstream guide surface. The valve includes a slide which is movable through the side opening into and out of positions in which its opposite side edges are received between the guide surfaces of the grooves and the guide assembly for guided movement between positions controlling the flow through the flowway. An actuator is mounted on a bonnet removably disposed over the side opening and having a stem extending sealably through the bonnet and into the side opening. The inner end of the stem and the slide are connected by a T- slot to permit limited lateral shifting of the slide with respect to the stem so that it may tightly engage the downstream guide surfaces of the guide assembly. Advantageously, the slide functions as a locking mechanism to align and lock the guide assembly and the inlet and outlet liners in place. Also, the interlocking portions between the inlet liner and the outlet liner with the refractory material are tapered to limit or reduce erosive bypassing. Thus, the refractory lining not only serves its traditional purposes in valves of this type but also supports and guides the slide. The wear prone parts are removable and replaceable through the bonnet and erosive bypassing is eliminated or reduced. Consequently, the valve of the present invention is considerably less expensive, easier and quicker to repair, and erosive bypass wear is eliminated or reduced than valves of this type of the prior art. Accordingly, it is an object of the present invention to provide a slide control valve for high temperature, abrasive use, such as used in oil refineries, which has wear prone parts readily removable and replaceable through the bonnet without the necessity of removing the valve from the line. It is yet another object of the present invention to provide such a slide control valve in which the refractory liner bears and supports the load on the slide. A further object of the present invention is the provision of such a slide control valve which has removable and replaceable wear prone parts, such as inlet and outlet liners, guides and guide assembly, which can be removed and replaced through a removable bonnet on the valve. A still further object of the present invention is the provision of such a control slide valve which eliminates or reduces erosive bypassing of the slide of the valve. Other and further objects, features and advantages of the invention are set forth throughout the specification and claims and which are inherent in the invention. Brief Description of Drawings Figure 1 is a vertical sectional view of a slide valve constructed in accordance with the present invention with the slide thereof shown in a throttling position with respect to the orifice. Figure 2 is a longitudinal-sectional view of the valve as seen along broken lines 2-2 of Figure 1. Figure 3 is a longitudinal-sectional view of an alternative embodiment of the valve similar to the view of Figure 2. Figure 4 is a longitudinal-sectional view of an alternative embodiment of the valve similar to Figure 2. Figure 5 is a longitudinal-sectional view of yet another alternative embodiment of the valve similar to Figure 2. Figure 6 is a cross-sectional view of a diverter valve constructed in accordance with the present invention with the slide thereof shown in a position closing one of the two outlets thereof. Figure 7 is a longitudinal-sectional view of the valve as seen along broken lines 7-7 of Figure 6. Best Modes for Carrying out the Invention With reference to Figures 1 and 2 of the above described drawings, the overall valve, which is indicated in its entirety by reference character 10, is shown to comprise an outer metal shell 11 and a lining 12 of refractory material which has been cast in place and thus secured on the inner surface of the shell to form a flowway 13 therethrough. A metal mesh, not shown, is secured to the inner surface of the metal shell 11, such as by welding, and the refractory material is cast in place through the metal mesh and then shaped, such as by troweling to form the flowway 13. With the valve disposed on its side, the flowway 13 is arranged vertically and includes an inlet 14 at its upper end, an outlet 15 at its lower end, and a side opening 17 therein which intersects the flowway 13 intermediate the inlet 14 and outlet 15. As previously 5 described, in valves of this type, the inlet is typically connected to a process flowline (not shown) and the outlet is typically connected to the downstream flow line. More particularly, the cast refractory lining 12 forming the inlet has a conical surface 18 which converges from its 10 upper end toward an orifice 19 at its intersection with the side opening. By casting the refractory lining 12 in place, it is capable of withstanding the load through the valve. As best shown in Figure 2, the flowway 13 has grooves 20 formed in its opposite sides with each groove 15 providing a downstream guide surface 21 at each side and an upstream guide surface 22 on either side. More particularly, the valve also includes a slide indicated in its entirety by reference character 23 and including a solid metal body 24 which is of such size as to be movable through 20 the side opening 17 into and out of positions in which its opposite side edges are received between the guide surfaces of the grooves for guided reciprocation between positions controlling flow through the flowway. The slide 23 is of a thickness somewhat less than the width of the cavity 25 intermediate the guide surfaces 21 and 22, and of a width somewhat less than the distance between the end surfaces of the grooves. As previously described, in a valve of this type, the slide normally occupies a position in which it throttles 30 flow through the orifice 19. That is, as shown in Figure 1, its leading edge is disposed generally intermediate the sides of the orifice 19. As shown in broken lines in Figure 1, the slide may be moved further into the valve body and thus in a rightward direction to a fully closed position in 35. an emergency. On the other hand, when it is necessary to fully open the valve, as may occur during start up, the slide may be moved in a leftward direction and thus toward a position more removed from the valve body to dispose its leading edge outwardly of the orifice 19. The slide is reciprocated between these positions by means of an actuator which is indicated in its entirety in Figure 1 by reference character 25 and includes a cylinder 26 mounted on a framework 27 having a bonnet flange 28 on one end adapted to be bolted to and thus releasably mounted on a flange 29 formed on the left-hand end of the metal shell 11 of the valve body. The bonnet flange has an opening therethrough forming a continuation of the outer end of the side opening formed in the refractory lining of the valve body, which openings are of a size to permit the slide to move therethrough during assembly and disassembly. The actuator also includes a piston (not shown) within the cylinder and having a stem 30 which extends sealably through a stuffing box 31 on the bonnet flange and thus into the side opening in the valve body. As indicated by a broken away portion of Figure 1 , the inner end of the stem is connected to the opposite end of the slide by means of a T-slot 32 which enables the slide to be reciprocated with the stem while permitting the slide to shift laterally with respect thereto. Thus, with the slide 23 positioned in the valve body as shown, it is free to move laterally so that its downstream side may tightly engage the downstream guide surfaces 21 of the grooves. More particularly, and as previously described, the refractory lining 12 is securely cast in place in the metal shell 11 and formed of a material which has sufficiently high compressive strength to enable the guide surface 21 to carry the load transmitted thereto by the slide 23. The load transmitted to guide surfaces 21 includes both the weight of slide 23 and the load on slide 23 resulting from impingement of the process flow on the upstream surface of slide 23, and to assist in bearing this load, the alternative embodiments shown in Figures 3-5, in which like structure is designated by a "primed" reference character, may be utilized to advantage. In the case of the embodiment shown in Figure 3, a portion of the load transmitted to downstream guide surfaces 21* is transferred to the shell 11' by the angling of guide surfaces 21' inwardly toward the flowway 13'. The inward angling of guide surfaces 21' in this manner introduces a radially outward component into the load transmitted by slide 23' to guide surface 21' whereby a portion of the load is born by the shell 11'. Likewise, the load transmitted to the angled downstream guide surfaces 21* of the embodiment shown in Figure 5 is transferred to the shell 11• . Referring now to the embodiment shown in Figure 4, the transfer of the load of the shell 11* is accomplished by positioning a portion of the shell ll 1 downstream of slide 23* opposite the outer side edges of slide 23• . This embodiment shown in Figure 4 is of particular utility in very high pressure applications and for applications in which inlet size is much larger than the diameter of orifice 19*; the embodiment shown in Figure 5 is preferred for use in lower pressure applications and/or in applications calling for an inlet size which is closer in diameter to the diameter of the orifice. Because the type of valve shown in Figures 1-5 is normally used for throttling purposes, it is not necessary that it maintain a tight seal between the upstream side of the slide and the upstream guide surface 22 about the orifice. Hence, it is possible to permit this lateral movement between the slide and the stem so as to transmit the load to the downstream of the refractory lining, while retaining the necessary tolerances between the slide and the lining to facilitate reciprocable movement of the slide. However, one of the advantages of the structure of the valve of the type shown in Figures 3 and 5 in which the downstream guide surfaces are angled inwardly toward the flowway is that such valves can be used to seal the flowway against passage of a process flow therethrough. In the preferred and illustrated embodiments of the invention, the slide 23 also includes a layer 33 of heat and erosion resistant material on the upstream side of the metal body 24. A suitable material for this purpose is known as the hexmesh and may be applied to the upstream side of the metal body in any suitable manner as is known in the art. As also shown in Figure 1, the side opening 13 in the refractory lining has a recess 35 formed therein which extends between the downstream side of the slide 23 and the outlet 15 from the valve body intermediate the grooves 20. This recess thus permits debris which would otherwise accumulate within the cavity to the left of the slide, as shown in Figure 1, to bypass the slide. As shown, the recess 35 is of essentially conical shape having its opposite end edges intersecting the inner edges of the downstream guide surfaces 21. Referring now to Figures 6 and 7, there is shown a diverter valve, indicated in its entirety by reference character 40, constructed in accordance with the present invention. Diverter valve 40 is shown to comprise an outer metal shell 41 and a lining 42 of refractory material which has been cast in place on the inner surface of the shell to form a flowway 43 therethrough. Thus, with the valve disposed as shown in Figures 6 and 7, the flowway 43 is arranged vertically and includes an inlet 44 at its upper end, a primary outlet 45, another, secondary outlet 46 to the side of the primary outlet 45 at the lower end thereof, and a side opening 47 which intersects the flowway 43 intermediate the inlet 44 and primary outlet 45, but with another line connected to secondary outlet 45 for diverting the process flow into the other line. The cast lining 12 forming the inlet is shown as a straight line, but could also be cast in the conical configuration of, for instance, the inlet 14 of the valve 10 of Figure 1. As best shown in Figure 7, the flowway 13 is provided With downstream guide surfaces 51 formed in the lining 42 of opposite sides thereof in a manner similar to the construction of the valve 10* shown in Figure 4 in which a portion of the shell 41 downstream of the slide 53 positioned therein is opposite the outer side edges of slide 53 for transferring the load of slide 53 thereto by the refractory lining 42. The upstream guide surfaces 52 are formed by the inside curved surface 58 of the lining 42 of the body 57 of valve 40, the side edges of side 53 being radiused to approximate the radius of that surface 58. Slide 53 includes a metal body 54 which is of such size as to be movable through the side opening 47 into and out of positions in which its opposite side edges are received between the guide surfaces 51 and 52 for guided reciprocation between positions controlling flow through flowway 43. More particularly, and as best shown in Figure 7, the width of slide 53 is somewhat less than the distance between the end surfaces of the inside surface 56 of the lining 42 of the body 57. In a valve such as the diverter valve 40, the slide normally occupies a position in which it controls flow out of primary outlet 45. That is, as shown in Figure 6, its end edge is disposed generally intermediate the two outlets 45 and 46, e.g., resting on or covering the portion 49 of the refractory lining 42 between outlets 45 and 46 as well as on the downstream guide surface 51. The slide is moved further into the valve body 57, and thus in a rightward direction, to close the primary outlet 45 and divert the process flow into secondary outlet 46. The slide is reciprocated between these positions by means of an actuator which is indicated in its entirety in Figure 6 by reference character 55 and includes a cylinder 56 mounted on a framework and bonnet flange (not shown) preferably having -li¬ the same or a similar construction as shown in Figure 1. The actuator 55 also includes a piston (not shown) within the cylinder 56 having a stem 60 which extends sealably through a stuffing box 61 on the bonnet flange and thus into the side opening in the valve body 57. Stem 60 is connected to slide 53 by means of a T-slot (not shown) which enables the slide to be reciprocated with the stem while permitting the slide to shift laterally with respect thereto. Thus, with the slide 53 positioned in the valve body 57 as shown, it is free to move laterally so that its downstream side may tightly engage the downstream guide surfaces 51. The construction of diverter valve 40 confers a number of advantages upon the valve of the present invention over previous known diverter valves. In addition to the elimination of the metal guides and the problems encountered in fabricating and assembling them into the valve body to precise tolerances, such valves are characterized by operational difficulties arising from this construction. For instance, the flow through the primary outlet may be at a nominal 1400°F while the "cold" secondary outlet may be several hundred degrees cooler than that temperature. The coefficients of thermal contraction and expansion of the refractory are different than those of the metal guides, and the coefficients of the guides may be different than those of the slide, such that maintaining specified clearances in the face of this temperature differential is problematical. This difficulty is increased by the fact that the amount of mounting hardware required for the metal guides is such that the two outlets 45 and 46 must be spaced far enough apart to allow the mounting of the guides, thereby increasing the temperature differential (and coincidentally the overall size and weight of the valve adding to its cost) . By contrast, the guide surfaces 51 and 52 of the diverter valve 40 are all formed in the refractory material, and that material has the same coefficient of thermal contraction and expansion throughout the entire valve body, minimizing thermally induced misalignment problems. Further, the two outlets are closely spaced (a matter of inches rather than perhaps as much as a foot or more) , decreasing the overall temperature differential from hot to cold outlet, and coincidentally, overall size and weight. Additional savings in size and weight result from the fact that the body, when viewed in the sectional view shown in Figure 7, need not be wide enough to accommodate the guides in the space between the inside surface 58 of lining 42 of body 47 and slide 53. To further minimize alignment problems, both leading and trailing edges of the slide 53 are preferably beveled as shown at reference character 62 to allow the slide 53 to plane up over the edge 48 of the refractory lining forming the primary outlet 45 or any irregularities in the lining forming downstream guide surfaces 51 or the portion 49 below primary and secondary outlets 45 and 46. Such irregularities may result, for instance, in the portion 49 of lining 42 between outlets 45 and 46 as a result of impingement of the process flow thereon or as a result of the cracking of the lining resulting from the above-described temperature differential from hot to cold sides of valve 40. In applications in which such impingement or cracking is problematical, the front to back dimension of slide 53 (and the portion of the body 57 indicated by reference character 59 which receives the leading, or front, edge of slide 53 when slide 53 is moved rightwardly in Figure 6) is increased so that the slide 53 covers the portion 49 completely when blocking secondary outlet 46. The radius of the upstream guide surfaces 52 and the weight and load on slide 53 provides the necessary resistance to any upward movement of slide 53 caused by any such irregularities in the portion 49 or guide surfaces 51 such that alignment problems in the vertical dimension are minimized as well. To counteract side-to-side alignment problems, the outside edges of slide 53 are also beveled as shown at reference character 64 such that slide 53 tends to be self-centering as it is reciprocated within body 57. Refractory material having sufficiently high compressive strength so as to be suitable for carrying the load transmitted by slide 23 is available from a number of suppliers, including Harbison Walker (Pittsburgh, Pennsylvania) , National Refractories (Oakland, California) , Norton Co. (Worchester, Massachusetts) , The Carborundum Co. (Niagara Falls, New York), Resco Products, Inc. (Morristown, Pennsylvania), Plibrico (Chicago, Illinois), and A.P. Green (Mexico, Missouri) . In a presently preferred embodiment, an abrasion resistant alumina-zirconia-silica composite sold under the trademark AR-400® by Premier Refractories and Chemicals, Inc. (King of Prussia, Pennsylvania) is modified as described below and cast in the shell using conventional techniques known in the industry to serve as the refractory lining. However, any such refractory material having a modulus of rupture (MOR) over about 1200 psi at normal operating temperatures (about 1400 to about 1900 psi is preferred) is suitable for use in accordance with the present invention, and many commercially available composites can either be modified by adding alumunina and/or zirconia to increase MOR or, by varying such parameters as aggregate size, cooling rate, pressure, percentage solids, vibration frequency, all as are known in the art, to minimize the strength thereof for use in accordance with the present invention. Another consideration, especially in larger diameter valves, in selecting a suitable refractory composite is resistance to shear. For example, referring to Figures 2, 3, and 5, the construction of the valve shown therein is such that the slide 23 is supported by a relatively unsupported, relatively large mass (especially in large diameter valves) of refractory material located immediately below, or downstream, of the downstream guide surfaces 21. The load transmitted into the refractory lining by slide 23, even with the transfer of a portion of that load to the shell 11, introduces a shear force into that portion of the refractory lining 42 such that the composition, method of application, and other variables of the preferred lining are preferably manipulated, again as known in the art, to optimize the resistance of the lining to such shear forces. In particularly demanding applications, composite devices such as rods, columns, pyramids, or other re-enforcing structure comprised of steel or other ceramic or composite materials may be affixed to the shell 11 or cast in the lining 12 to impart the necessary degree of shear resistance to the portion of the lining immediately downstream of the downstream guide surfaces 21. In particularly demanding applications, additional load bearing capability can be achieved by adjusting the dimensions of the downstream guide surfaces 21 (or 51 in Figures 6 and 7) and slide, relative to the orifice diameter, so as to increase the surface area of the refractory material to which the load of the slide and process flow is transmitted. In other words, by increasing the width of the slide and the depth of the grooves in the refractory lining 12 (or 52 in Figures 6 and 7) which form the guide surfaces (subject to the requirement that a minimum thickness of lining be retained between flowway and shell so as to provide the necessary thermal resistance capabilities) , the load is spread over a larger surface area, effectively increasing the compressive and shear strength of the lining. As noted above, suitable composites may be cast in place, and that capability illustrates another significant cost saving advantage of the present invention. In particular, the ability to cast the guide surfaces 21 and 22 (or 51 and 52 in Figures 5 and 6) in place eliminates the requirements that the prior art metal guides of valves such as are shown in the above-mentioned U.S. Patent No. 3,726,306 be ground to precise specifications because no grinding of the guide surfaces is required. Additional savings and precision can be achieved in some applications by actually using the appropriate slide as a portion of the framework for casting the lining. Although the refractory lining is illustrated to have been cast in one piece to the inner surfaces of the metal body, it may be cast in sections. As shown, the metal shell comprises separate sections welded to one another, including a cylindrical section through which the flowway is formed and lateral sections surrounding the portion of the refractory lining which forms the side opening from the flowway. The metal shell is of sufficient size and strength to provide a form to which the refractory lining may be cast. Further embodiments of the invention are the inclusion of replaceable wear prone parts. In general, these include wear prone portions or segments of the inlet and outlet liners, and a replaceable guide assembly. These may consist of single or multipart members and the liner portions may be threaded, keyed or otherwise releasably secured in place. Advantageously, the slide or disk functions as a locking mechanism to align and lock the guides, guide assembly, and inlet and outlet liners in place. More specifically, and referring now to Figure 1, releasable inlet liner insert 18a and releasable outlet liner 21a are threaded, keyed or otherwise releasably secured to the liner 12. As illustrated, the inserts may be a single member 21a or a multipart member 21a with the parts keyed together. The tapers 21b between the parts limit, reduce or eliminate erosive bypassing. Similarly, in Figures 2, 3, 4, 5, 6 and 7 replaceable inlet and outlet liner inserts 18a and 21a are shown in place and are releasable and replaceable through the bonnet. The inserts may be tapered as desired and as illustrated in Figure 5. As illustrated in Figures 2, 3, 4, 5, and 7, removable and replaceable guide assembly or guides 66 may be provided. These may take a variety of shapes, as illustrated in these drawings, and, if desired, the guides are keyed (not shown) to the refractory material. The valve slide or disc 53 functions as a locking mechanism to align and lock the liner inserts and the guide assembly or guides 66 in place. Thus, the wear prone parts are readily removable and replaceable through the bonnet without having to remove the valve from the line. As illustrated in Figures 2, 3 and 5, a cast refractory seal 67 may be used to seal the lining inserts 18a and 21a with the liner 12. The present invention, therefore, is well suited and adapted to attain the objects and ends and has the features mentioned as well as others inherent therein. While presently preferred embodiments have been given for purpose of disclosure, changes can be made therein which are within the spirit of the invention as defined by the scope of the appended claims. What is claimed is:

Claims: Claims 1. A slide valve for high temperature and/or abrasive service, comprising a body having an outer metal shell and a lining of refractory material securely cast to and supported by the inner surface of the shell to form a flowway therethrough having an inlet and an outlet and a side opening intersecting the flowway intermediate the inlet and outlet, said flowway having upstream and downstream grooves formed in its opposite sides with each groove providing upstream and downstream guide surfaces at each side thereof, a slide which is movable through the side opening into and out of positions in which its opposite side edges are received between the guide surfaces of the grooves for guided reciprocation between positions controlling flow through the flowway, an actuator for so reciprocating the slide including a bonnet removably mounted over the side opening and a stem extending sealably through the bonnet and into the side opening, the inner end of said stem and the body of the slide being connected for reciprocating the slide with the stem while permitting limited lateral shifting of the slide with respect to the stem so that it may tightly engage the downstream guide surfaces, and said refractory material having sufficiently high compressive strength to carry the load transmitted thereto by the slide. 2. A slide valve of the character defined in Claim 1, wherein the slide includes a layer of heat and abrasion resistant material on the upstream side of a metal body. 3. A slide valve of the character defined in Claim 1, wherein the side opening has a recess which extends between the downstream side of the grooves and the outlet intermediate the grooves to permit debris to bypass the slide when in position to throttle flow through the orifice. 4. A slide valve of the character defined in Claim 1, wherein the downstream guide surfaces of the grooves are angled inwardly toward the flowway for transferring a portion of the load transmitted to said refractory material to the outer metal shell. 5. A slide valve of the character defined in Claim 1, wherein said body flowway has another outlet to the side of the first mentioned outlet, and the slide is reciprocated by the actuator between positions controlling flow through one or the other of the outlets. 6. A slide valve of the character defined in Claims 1, wherein the upstream guide surfaces of the groove taper from the flowway toward the outer edges of the downstream guide surface. 7. A slide valve of the character defined in Claim 1, wherein the metal shell of a portion of the body downstream of the slide is opposite the outer side edges of the slide so that the load of the slide is transferred thereto by the refractory lining. 8. A slide valve of the character defined in Claim 1, wherein the inlet of the flowway includes at least one lining insert of refractory material removably secured to the lining of refractory material adjacent the upstream groove, the lining insert being removable and replaceable through the bonnet. 9. The slide valve of the character defined in Claim 1, wherein the outlet of the flowway includes at least one lining insert of refractory material removably secured to the lining of refractory material adjacent the downstream groove, the lining insert being removable and replaceable through the bonnet. 10. A slide valve of the character defined in Claim 1, wherein the inlet and the outlet of the flowway includes at least one lining insert of refractory material removably secured to the lining of refractory material adjacent the upstream and downstream grooves, and the lining insert being removable and replaceable through the bonnet. 11. A slide valve of the character defined in Claim 1, wherein the flowway includes a plurality of lining inserts of refractory material removably secured to the lining of refractory material adjacent the upstream and downstream grooves, adjacent lining inserts having interfitting portions on their abutting surfaces, the inserts being removable and replaceable through the bonnet. 12. A slide valve of the character defined in Claim 1, wherein at least the downstream guide surfaces of the grooves comprise removable and replaceable guide surfaces through the bonnet. 13. A slide valve of the character defined in Claim 1, wherein the flowway includes a plurality of lining inserts of refractory material removably secured to the lining of refractory material adjacent the upstream and downstream grooves, adjacent lining inserts having interfitting portions on their abutting surfaces, and at least the downstream guide surfaces of the grooves comprise removable and replaceable guides, the lining inserts and the guides being replaceable through the bonnet, the slide locking and aligning the lining inserts and guides in place.

Inventors: PURVIS HOWARD A, PURVIS, HOWARD, A.
Applicants: PURVIS HOWARD A, PURVIS, HOWARD, A.
Application year: 1991
Main classification: F16K49
IPC codes: F16K3, F16K49