Note: Descriptions are shown in the official language in which they were submitted.
0 7 70
B~CKGROIIND OF THE IN~7E~ITION
2 Slide valves generally are used for three general
3 types of services including the throttling of flue gas con-
4 taining solid particles, and the throttling and/or blocking
of solids flow. This type of valve is used extensively in
6 fluid catalytic cracking units (FCCUs), fluid coking units
7 (FCU's), fluidized iron ore units (FIOR's) and other fluid-
8 ized solids units where service conditions may vary between
9 ambient and 1600F. over long periods of time and as high
as 1800~F. for a short time and pressures range from O to
11 250 psig. In these processes, the operating pressure is
12 controlled by throttling the flow. Of course slide valves
13 also hsve utility in various other processes. Presently,
4 three basic types of valves are used in the type of environ-
ment discussed above, including different configurations
16 for vertical and horizontal conduits to account for the
17 orientation of the valve. A conventional slide valve con-
18 figuration with the disc(s) in a tongue and groove guide
19 arrangement is disclosed in U.S. Patent 3,726,306.
~ In the case of fluid solids flow, both blocking
21 and throttling valves are used. Generally, however, block-
22 ing of solids flow is accomplished by employing a single
23 disc-type valve which covers an opening provided in a fixed
24 orifice plate. The valve usually offers no restriction to
flow when it is fully opened, i.e., the orifice opening is
26 equal to the line diameter. Conventional throttling slide
27 valves operate with a reduced port or opening in order to
28 achieve the desired flow control. The ori~ice generally is
29 considerably less thsn the line diameter depending upon the
pressure drop required for proper operation. 8ecause the
31 valves are sub~ect to substantially constant (solids) par-
32 ticle flow implngement at elevated temperatures which are
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1 high enough to significantly reduce the physical strength
2 and hardness of the valve material, erosion of these valves
3 $s likely to occur. Erosion can substantially reduce the
4 operating life of this key piece of equipment, which can
present a major problem since the valves are a critical
6 component of process units whose economic success is de-
7 pendent on long-term uninterrupted operation. Typical
8 prior art valves which have been employed are disclosed in
9 U.S. Patent Nos. 2,217,834; 2,614,789; 2,636,712; and
lo 3,370,610.
11 Of these prior art patents, Lubbock, U.S.
12 2,636,712, which is assigned to the assignee of the present
13 invention, appears most pertinent in that it discloses a
14 slide valve/internals configuration for the flow control of
solids. However, the primary emphasis of L~bbock is to
16 co~lpensate for erosion of valve internals by repositioning
17 the discs relative to the seat. One or a plurality of ports
18 (seats) can be provided in the valve orifice plates. The
19 slides are spaced apart a desired distance to provide the
desired orifice flow area. As the slides and/or orifice
21 plates erode in the area of flow, the slide discs are moved
22 (with the distance between maintained) relative to the open-
23 ings in the orifice plate so that the eroded areas of the
24 valve internals are removed from the flow exposure and dif-
ferent nonworn portions of the valve are exposed to the
26 erosive action of the flow. Neither Lubbock or the other
27 prior art valves have the specific construction details of
28 the present invention or provide for a variable flow area
29 or other advantages afforded thereby.
SUMMARY OF THE INVENTION
31 Accordingly, it is a primary object of the pres-
32 ent invention to provide a slide valve which will avoid the
' ~07 ~ O ~0
.
l deficience~ of the prior art valves described heretofore.
2 Another primary object of the present invention
3 is to provide a slide valve which will operate in substan-
4 tially any positlon.
~ further primary object of the present invention
6 is to provide an improved slide valve having capability to
7 provide a variable flow area.
8 A further object is to provide a slide valve hav-
9 ing a unitized internal construction whi~h simplifies re-
moval of the internals and permits easy reassembly and
ll adjustment.
12 Another object of the invention is to provide a
13 slide valve with improved erosion protection.
14 Still yet a further object of the present inven-
tlon is to provide an improved slide valve wherein the
16 sl~des are in bearing contact with the valve seat and the
17 movement of the discs is restrained to a back and forth
18 motion, and is capable of use with substantially any valve
19 operator.
~ According to the present invention, there is pro-
21 vided a multi-position double disc slide valve which is es-
22 pecially useful in erosive and/or high temperature service.
23 The valve has a fixed orifice and a pair of solid discs
24 which are restrained for back and forth, i.e., reciprocating,
movement for creating a variable size flow orifice=which
26 makes the valves suitable for either throttling or blocking
27 service. The discs are not capable of achieving gas tight
28 shutoff because of inadequate seating force developed be-
29 tween the discs and the seat by the differential pressure
3~ and/or the sealing surfaces cannot be economically fabricated
3l to the necessary tolerances. They are automatically actu-
32 ated by the suitable conventional operators such as air
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1 motor, hydraulic cylinder, pneumatic cylinder and/or di-
2 aphragms and the like. Because of their unique construction
3 and arrangement, the valves are particularly effective and
4 useful under extremely erosive conditions such as fluidized
solids service. Each of the discs employ a separate oper-
6 ator which increases reliability of the valves. This allows
7 one operator can be serviced while the other is in opera-
8 tion. When throttling, the valve discs are supported by and
9 are in intimate, direct bearing contact with the orifice
plate or seat, whether the valve is mounted in a horizontal
11 or vertical line, with downflow, or in any intermediate
12 position. When the valve is in the closed position but
13 without differential pressure forcing the discs against the
14 seat the guides prevent the discs fromdisengagement for
valves installed in horizontal lines. Erosion control of
16 th~ valve internals is accomplished by refractory (integrally
7 reinforced) and hard surfacing on the discs and orifice
18 plate (seat). The valve body is protected with refractory
19 linings. The internals of the valve which are susceptible
to erosion are designed with a unitized feature to facili-
21 tate their replacement in a simple manner without the need
22 for removal of the complete valve from the line. These
23 parts include the orifice plate, the discs, and the guides
24` which are secured together by bolting into an assembly as
2s a unit. ~n those instances where severe erosion ~ antici-
26 pated, i.e., high differential pressure across the variable
27 orifice in a line containing flow with high solids content,
28 a number of conventional throttling valves (e.g., single
29 disc slide valves) in series have been required to insure
a reasonable time period between plant shutdowns. Where
31 space limitations do not permit the installation of two
32 or more single disc slide valves in series, a double disc
- 5 -
.
107701
1 throttling slide valve according to the present invention
2 can be used. The double disc valve then can throttle with
3 one of its slides, while the other slide is maintained in
4 a fully opened position. When the flow control is impaired
S because of erosion of the active or operating disc and the
6 corresponding section of the fixed orifice (seat), the
7 eroded disc can be moved to its full open position while
8 flow control is assumed with the other uneroded slide and
9 uneroded fixed orifice plate. This capability allows the
o subject invention to provide the service life of two con-
11 ventional single slide valves in the space of one valve or
12 the service life of four conventional valves in the space
13 required for two valves.
14 ~ Thus, it is apparent that a valve constructed
according to the present invention provides a valve design
16 with features which afford low operating costs and relative-
17 ly trouble-free maintenance. The valve will operate in es-
18 sentially any position in comparison to conventional valvees
19 which now are almost exclusively used in only vertical
lines. The internals are easily removed through a detach-
21 able bonnet which allows the valve body to be welded into
22 the line to make it leak-free, in place of using a conven-
23 tional flange configuration, i.e., bolted line construction
24 for high temperature service which is subjec. to leakage.
The use of such a unitized internal valve construction in
26 downflow and horizontal line valve applications, simplifies
27 the removal and replacement of internals, i.e., one assembly
28 through the use of spares. This configuration permits re-
29 pair, reassembly and adjustment in the shop during unit
operation, thus avoiding rush type reconditioning without
31 increasing the initial valve cost. The unitized construc-
32 tion permits simplified and therefore, more reliable guiding
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1077010
of the valve movement. Only one critical dimensional clearance
is required in comparison to conventional valves which require
at least three such dim,ensional clearances. The operators for
the valves have broad flexibility and may comprise any one of
a variety of conventional systems (e.g., hydraulic, pneumatic,
etc.).
In accordance with a specific embodiment, ~n
improved slide valve adapted for use in the control of processes
containing fluid flow with erosive materials and at high
temperatures comprises, in combin ~ion, (a) a valve body
compri~ing a wall defining a central flow passage along a main
axis connected by an inlet and outlet for unidirectional flow
from said inlet to said outlet and including opposed openings in
said wall transverse of said main axis, (b) an orifice plate
removably mounted in said valve body between said inlet and
outlet and including an orifice opening of fixed dimensions and
substantially perpendicular with respect to said main axis,
said orifice plate having an i'nlet side which always faces said
inlet and an outlet side which always faces said outlet, (c)
a pair of opposed disc member~ ~ounted in said valve body in
s~bstantially the same plane as said opposed openings for slidiny
movement in a direction perpendicular to said main axis of -~aid
central flow passage, said disc members located only on said
inlet side of said orifice plate and arranged in direct surface
bearing contact with said inlet ~ide of said orifice plate for
substantially eliminating clearances and fluid bypass between
said disc members and said orifice plate, said members con-
structed and arranged for providing a variable flow area between
opposed inner ed~es with respect to said passage; td) guide means
secured with said valve body only on said inlet side of said
orifice plate for constraining movement of said discs to a pre-
B
~0770~
determined path substantially in the plane o f said opposedopenings in said valve body and preventing substantial transver5e
movement of said disc3, and defining together with a portion of
said inlet side of said orifice plate the path of movement of
said di~cs, and (e) operator mean9 connected for selectively
moving each of said discs.
In accordance with a further embodiment, an improved
slide valve adap ed for use in the control of processes containing
fluid flow with erosive materials and at high temperatures com-
prises, in combination: (a) a valve body comprising a walldefining a central flow passageway along a main axis connected by
an inlet and an outlet for unidirectional flow from said inlet
to said outlet and having opposed openings in said wall transverse
of said main axis; (b) an orifice plate removably mounted in said
valve body between 5aid inlet and said outlet and having a fixed
orifice opening disposed substantially perpendicular with respect
to said main axis, said orifice plate having an inlet side which
always faces said inlet and an outlet side which always faces said
outlet, said orifice plate including refractory means on one
surface on said inlet side thereof surrounding said fixed opening
and further protective means on said one surface between said
refractory means and the outer edges thereof, (c) a pair of
opposed di~c members slidably mounted in said valve body sub-
stantially in the same plane as said opposed openings only on
said inlet side of said orifice plate for sliding movement in direct
surface bearing contact with said one surface of said orifice
plate in a direction perpendicular to saîd main axis during
operation of said valve, said members constructed and arranged for
providing variable flow area between opposed inner leading edges
thereof with respect to said passageway, refractory means on said
discs on the surface thereof facing said inlet and further
- 7a ~
lV-~OlV
protective means on opposite surface thereo~ for facilitating
relative sliding movement of said discs with respect to said
orifice plate, (d) guide means secured with said valve body only
on qaid inlet side of said orifice plate on transversely opposite
sides of said disc members with respect to their path of movement
for constraining movement of said discs in a predetermined path
substantially in the plane of said opposed openings in said valve
body and preventing substantial transverse movement of said
discs with respect to the path of movement, said guide means having
inner surfaces facing said disc members and a coating on said
inner surfaces for facilitating relatively free sliding movement
between said guide m~ans and said disc members, and defining with
a portion of said one surface of said orifice plate the path of
movement of said disc members~
In accordance with a still further embodiment, an
improved slide valve adapted for use in the control of processes
containing fluid flow with erosive materials and at high tempera-
ture comprises, in combination: (a) a valve body comprising a wall
defining a central flow passageway connected by an inlet and an
outlet and having opposed openings in said wall, (b) an orifice
plate removably mounted in said valve body between said inlet and
said outlet and having a fixed orifice opening disposed sub-
stantially perpendicular with respect to the flow through said
passageway, ~aid orifice plate including refractory means on one
~urface at least directly adjacent said orifice opening, (c)
disc means slidably mounted in ~aid valve body substantially in
the same plane as said oppo~ed openings for sliding movement in
total bearing surface contact with said one surface of said
orifice plate in a direction perpendicular to the axis of said
central flow passageway when said valve is operating, said disc
means for providing variable flow area with respect to said
-7b~-
D
~,~r7701~ '
passageway, refractory means on said disc means on the surface
thereof facing the direction of flow and further protective means
on the opposite surface thereof for facilitating relative sliding
movement of said disc means with respect to said orifice plate,
(d) guide means secured with said valve body on transversely
opposite sides of said disc means with respect to their path of
movement for constraining movement of said disc means in a pre-
determined path substantially in the plane of said opposed open-
ings in said valve body and preventing substantial transverse
movement of said disc means with respect to the path of movement,
said guide means having inner surfaces facing said disc means
and a coating on said inner surfaces for facilitating relatively
free sliding movement between said guide means and said disc
means.
Having in mind the foregoing that will be evident
from an understanding of this disclosure, the invention
comprises the construction and arrangement of parts for a valve
and its use in fluid solid service as disclosed in the preferred
embodiment of the invention, which is hereinafter set forth in
such detail as to enable those skilled in the art readily to
understand the function, operation, construction and advantages
of it when read in conjunction with the accompanying drawings.
BRIEF DESCRIPTIO~ OF THE DRAWINGS
Fig. 1 is a perspective view of a preferred
embodiment of a valve constructed and arranged according to the
present invention for use in fluids solid service.
Fig. 2 is a top plan view of the valve of Fig. 1.
Fig. 2A shows the operator stem connection with
the valve disc.
Fig. 3 is a cross-sectional view taken substantially
along the line 3-3 of Fig. 2.
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:~077010
Fig. 4 is a cross-sectional view taken ~ubstan-
tially along the line 4-4 of Fig. 2.
FigO 5 is a cro~s-sectional view taken substan-
tially on the line 5-S of Fig. 1.
Fig. 6 is a top view of the fixed orifice plate
used in the valve of the present invention.
Fig. 7 is a cross-sectional view taken substan-
tially on the line 7-7 of Fig. 6.
- 7d - .
B'
~0~70~0
1 Pig. 8 is a cross-sectional view taken substan-
2 tially on the line 808 of Fig. 6.
3 Fig. 9 is a cross-sectional view of a portion of
4 the disc taken substantially along the line 9-9 of Fig. l.
Fig. lO is a cross-sectional elevation view of
6 reinforced refractory illustrating the anchors according
7 to the present invention taken substantially on the line
8 lO-lO of Fig. 6.
9 Fig. ll is a top view illustrating the reinforced
refractory anchor ,arrangement of Fig. lO according to the
11 present invention.
12 Figs~ 12 and 13 are elevational view of the disc
13 guide illustrating the hard surfacing areas thereon.
14 Fig. 14 is a schematic top plan view of a fixed
orifice plate having an oblong opening.
16 Fig. 15 is a schematic top plan view of a fixed
17 orifice plate having a circular opening.
18 Fig. 16 is a t~p plan view of an alternate embodi-
19 ment of the valve discs having concave leading edges for
throttling use.
21 DESCRIPTION OF THE PREFERRED EMBODIMENT
22 Referring now to the drawings wherein like parts
23 are designated by the same reference numeral throughout the
24 several views, there is disclosed a multi position slide
valve lO which is particularly adapted to fluid solid service,
26 especially for throttling flow and more particularly for
27 use in controlling the flow of erosive fluids which contain
28 solids. The valve basically comprises a pair of discs 12,
29 14 which are located diametrically opposite each other
~ across a valve orifice 16 with fixed dimensions. Each slide
31 bears or rests directly on the orifice plate 22. In opera-
32 tion one of the discs can be removed from the flow path
10'77 0~
1 (shown downward by the arrow, although flow can be in
2 other directions depending on line orientation) while the
3 other is used for flow control and when the used slide is
4 eroded too much for effective control, it can be positioned
away from the flow path and the other disc used in lieu
6 thereof. Alternatively, both of the discs can be employed
7 to control flow through the orifice. As shown in Fig. 1,
8 the valve generally designated 10 comprises the pair of
9 opposed solid disc members 12 and 14 having a generally
lo rectangular cross-section, with each of the discs squared
11 or straight along its inner or leading edge. This applies
12 primarily to solids flow throttling type valves which
13 block solids flow when the discs are in closed position.
14 When the leading opposed edges of the discs are spaced
apart a predetermined distance, they effectively provide
16 the desired orifice opening between the discs. A rectan-
17 gular shaped orifice opening 16 (see Fig. 6) is formed
18 centrally in the orifice plate 22 which is disposed on the
19 underside of the discs and is in direct or cintiguous slid-
ing contact or relation with the disc members 12 and 14.
21 On the upper side of the disc members 12 and 14 and disposed
22 ad;acent to the transverse sides or edges thereof are a
23 pair of essentially parallel elongated guide bars 24 and
24 26 wh~ch insure that the movement of the slides will be
limited to a back and forth motion, thus effectively pre-
26 venting undesired up and down movement. Side retainer
27 bars 28 and 30 (see Figs. 5 and 8) are secured with the
28 upper guide bars and are located directly below them along
29 the transverse edges of the discs for containing ~he disc
and preventing substantial undesired side to side movement.
31 The transverse spacing is in the range of between about 1/8"
32 to about 3/16". By this type of disc containment o~ly one r
~770~o.
1 truly critical clearance is required by comparison to the
2 three critical clearances normally required in conventional
3 slide valve designs. Thus, the only critical clearance
4 for slide valves according to the present invention is th~t
between the undersurface of the upper guides 24, 26 and the
6 upper surface of the disc members 12, 14, which preferably
7 should have a tolerance range of + 0.005 inches. In the
8 typical tongue-in-groove type arrangement, e.g., see U.S.
9 3,726,306, tolerances must be maintained not only for this
particular dimensipn but also between the disc(s) and the
11 fixed orifice plate (ver~ical) and between the discs and
12 the tonguie-and-groove guides in the horizontal direction
13 on each side of the discs. The typical movement of the
14 discs can best be seen by reference to Fig. 2, wherein the
discs 12, 14 shown in solid lines correspond to the posi-
16 tions shown in Fig. l. When the discs are moved inwardly
17 toward each other so that their leading edge surfaces 18
18 and 20 contact each other the valve is in the closed posi-
19 tio~-
As further shown in Fig. 2, the line A is repre-
21 sentative of the maximum opening between the discs, where-
22 as line B represents the opening normally employed during
23 operation of the valve. The dotted centerline C represents
24 the center of the fixed orifice opening 16 and corresponds
to total valve closure, i.e., there is no minimum opening
26 for the type of disc design where the leading disc edges
27 are in abutting contact (e.g. squared or straight edge).
28 If the length of the discs is equal to or slightly greater
than the maximum orifice diameter or opening, then only one
~ of the discs can be used to close the valve provided that
31 the other disc has been placed in 8 fully retracted position.
32 Other variations in the size of the disc are, of course,
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10770~
1 possible and will occur to those sk;.lled in the art in
2 order to accommodate a desired flow pattern. An alternate
3 embodiment for the discs is shown in Fig. 16 wherein the
4 leading edge of each disc includes a concave portion 17
S which is centrally located of the disc sides. This con-
6 struction is useful when there is no need for shut-off
7 since these always will be a minimum opening (shown
8 by the dotted line) with the discs in their innermost
9 or closed position. Thus, it will have utility when
lo throttling is desired (e.g. flue gas pressure control).
11 The upper and transverse disc guide bars are secured to-
12 gether by means of a plurality of threaded bolts 32 such
13 as shown in Fig. 4. The annular orifice plate 22 is mounted
14 to a lower annular support member 34 by means of bolting
as shown by 36 and extends radially inward therefrom about
16 the fixed orifice 16 (e.g. rectangular). Although in the
17 preferred embodiment the orifice opening is shown as sub-
18 stantially rectangular, it is within the scope of this in-
19 vention and contemplated to have other shapes. For example,
the opening may be oblong (see Fig. 14) or circular (see
21 Fig. 15). The fixed opening by having its major axis a~
22 l~gned in the direction of the valve stems will insure a
23 more centralized flow from the variable orifice between the
24 discs to minimize erosive impingement of solids on the
i 25 valve body. Of course, the fixed orifice opening is sized
26 to provide desired rangeability and control of the flow.
27 The outer end of the annular support 34 is welded about its
2~ periphery shown at 38 to the inner wall of the generally
29 circular cylindrical valve body 40 which contains the ori-
fice plate, discs and guides. The support 34 is additionally
31 supported on its underside by a plurality of circumfer-
32 entially spaced radial-extended gussets 42. The valve body
- 11 -
107'70~V
l is connected at one side (the inlet in the preferred em-
2 bodiment) to the carbon steel line 44 which forms part of
3 the process flow line in which the valve is used and at its
4 bottom or outlet side is connected to another carbon steel
line 46.
6 The valve discs generally operate or move in a
7 plane perpendicular with respect to the process flow
8 through the line. In the valve body there are a psir of
9 diagonally opposite openings 48, 50 which accommodate the
back and forth or recipr~cating movement of the respective
ll discs. Through these openings extend stems 52 which
12 are connected at one end by "Tee" bar ends, 51 and 53 in
13 recesses 56 and 58 (see Fig. 2A) respectively in the discs
14 12 and 14 and at their other end or outer extremities to
operators 60 and ~2 in a conventional ma~ner. As previously
l6 explained, the operator may be of the penumatic, hydraulic
~7 or other conventional type, e.g., air motor, electric motor,
18 hydraulic or air piston/cylinder system or diap~ragm. T~e
l9 operators 60 and 62 are identical and both are connected
20~ to the discs in the same manner. The stems 52 pass through
21 pedestals 64. Coaxial with the stems are anti-rotation nuts
22 66 which prevents any tendency of the stems to turn or ro-
23 tate as the disc reciprocates, which in turn prevents any
24 rotational tendencies of the disc members. The nuts 66 are
contained within a groove 68 provided in the pedestals.
26 ~uring valve operation diagonally opposite openings 48,
27 50 in the valve body, are covered by rectangular bonnet
28 covers 70 having a central opening 72 in which is mounted
29 a standard stuffing box 74 (i.e., compressible packing
rings arranged around stems 52 which pass through opening
31 72 and concentrically through 74). The stuffing box is
32 secured to the mounting cover by welding. Brackets 76
- 12 -
r .
1~77010
1 reinforce the pedestal base flanges 77 and 78. The bonnet
2 cover 70 is removably mounted by means of bolts disposed
3 about its perimeter and secured to the extended bonnet
4 flange 80 and gussets. The bonne~ cover and mou~ting sup-
ports the operators radially outward from the valve body.
6 Appropriate connections are made to power the operator hy-
7 draulically, by air, electrically, etc., as the case may be.
8 Thus, it is seen that a double disc arrangement
9 according to the present invention can center the discharge
0 flow in the process line, which substantially reduces flow
11 impingement on the inner pipe walls. Or the discs can be
12 used for throttling by maintaining one disc for throttling
13 purposes with the other maintained in a full open position,
14 i.e.~ fully withdrawn, and when erosion limits the flow
control attainable the eroded disc is moved to its full
16 open position and the other or second disc then is used to
17 control the flow. This is essentially like having two valves
18 in one and makes the valve especially suitable for applica-
1~ tions where long operating periods (runs) are desired, but
space limitations preclude installation of a second or third
21 valve. Also, by ensuring that the discs are always in con-
22 tact with the seat regardless of the valve orientation,
23 erosion resulting from bypass flow between ~he discs and
24 seat is avoided (in conventional valve a clearance is pro- -;
vided which permits such flow). While the disc and seat
26 may not always be in intimate contact, e.g., when the valve
27 is mounted in a vertical line with upward flow, the valve
28 still will operate satisfactory in such orientation so long
29 as the pressure drop across the valve is greater than the
opposite weight effect of the discs, which is a matter of
31 deslgn within the scope of the invention. This pressure
32 differential will cause the discs to maintain bearing con-
- 13 -
~7010
1 tact with the orifice plate. When the slides arè in bear-
2 ing contact, any flow which might normally bypass between
3 the disc and the seat is thus eliminated. Also, because of
4 this large surface to surface contact, the thrust force due
to the differential pressure drop across the valve is car
6 ried by the seat and not by the valve discs or guides.
7 This then permits a reduction in the thickness of the discs
8 which are fully supported by the seat. In conventional
9 valves the discs are supported by the tongue and groove
guides at the extreme width of the discs thereby subjecting
11 the discs to the full pressure thrust in a bending mode of
12 loading. Maintenance of the valve according to the present
13 invention is particularly simplified because of its unitized
14 internal construction and is facilitated by the full access
bonnet opening through which the internals assembly can be
16 removed as a single unit after unbolting the bolts 36 and
17 removing the bonnet cover. To reduce the cost one large
18 bonnet can be used rather than two. For the latter case the
19 stuffing box 74 is provided directly in the valve body as
well as the support arrangement 77 and 78 for the operator
2~ pedestal 64.
22 The desired erosion protection is accomplished by
23 providin~ hardsurfacing and integrally reinforced refrac-
24 tory as discussed in detail hereinafter. The hardsurfacing
may comprise a material such as Stellite 6 or some other
26 suitable anti-galling material, i.e., on which would prevent
27 the well-known phenomenon of welding of the sliding mater-
28 ials together. Stellite 6 is a high temperature hard
29 surfacing material which is applied by a welding process and
is characterized by being an extremely hard and wear resist-
31 ant coating. The hardsurfacing which is deslgnated by 82
32 throughout is employed on all of the load bearing surfaces
- 14 -
~ '70 i~
1 of the fixed orifice, on the guide surfaces facing the
2 discs and on the load bearing surfaces of the discs which
3 face the orifice plate, and is best shown in Figs. 6 through
4 9. On the orifice plate 22 the hardsurfacing 32 is disposed
about the plate periphery and extends outward of the ori-
6 fice periphery, adjacent to either end and adjacent the
7 guides on either side of the plate.
8 Reinforced refractory generally designated 84 is
9 also disposed about and directly adjacent the orifice open-
lo ing 16 on all sides thereof inward of the hardsurfacing.
11 While various types of refractory can be used9 a suitable
1~ one may basically comprise a high alumina chemical setting
13 refractory with at least 89% tubular alumina. The re-
14 fractory is compounded wlth phosphoric acid to develop
suitable bonding. A number of commercially available re-
16 fractories used for this type of service are made by Re-
17 fractories Specialties Co. (Resco) A22 and Babcock and
18 Wilcox Kosphos 30. The refractory is integrally reinforced
19 with well-distributed alloy fibers which are approximately
3/4" to 1" long and of 0.010"-0.013" diameter or with a
21 rectangular cross section approximately 0.010" x 0.030". ;
22 The fibers are added to the refractory while it is being
23 mixed at a typical ratio of between 1/2 volume % to 2 volume r
24 %. The former represents a weight of 2.4 pounds of fiber
per cubic foot of refractory, while the latter is 9.6
26 pounds per cubic foot of refractory. The reinforced re- ;
27 fractory 84 is disposed on the load bearing top side of the
28 orifice plate 22 at 86 surrounding the orifice opening 16,
wrapping around the vertical walls at 88 defining the open-
ing 16, and extending along the bottom side of the plate
31 at 90 directly adjacent the opening. See Flgs. 6 and 7.
32 In a typical construction, the refractory 84 extends from
15 -
~ ~,~
1~7'701~
1 the opening 16 outward about 8" on the top side and approx-
2 imately 4" on the bottom side. On the discs 12, 14 (see
3 Fig. 9), the refractory 84 is disposed completely on the
4 top side at 92 and on the side surface at 94, as well as
5 for about 4" inwardly from the ends on the bottom side as
6 shown at 96. The construction of the discs is identical
7 and therefore, only one is illustrated and discussed in
8 detail. Also on the bottom surface disc inward of the re-
g fractory is the hardsurfacing 82, since that portion is in
contact with the o~ifice plate 22. Typically, the refrac-
11 tory lining has a thickness of 2" and is supported and
12 fastened in place by a plurality of wire anchor loops 98
13 which are wleded as shown at 100 to the surfaces 102 of the
14 valve which are to be reEractory lined. These loops may,
for ex~mple, comprise 1/8" diameter wire welded at their
16 contact point with the vaive surface and ext.ending longitu-
17 dinally in transverse spaced relation. The loops would ex
18 tend with their raised portions or lands shown at 104
19 located about midway of the thickness of the reinforced lin-
ing, being welded in place to the valve surface at their
21 contact points. The wire loops can be transversely spaced
22 apart approximately 3" and are staggered longitudinally so
23 that for adjacent loops the welds of one are generally op-
24 posite the raised portion of the other, as best shown in
25 Fig. 11.
26 While a particular preferred embodiment of the in-
27 vention has been shown and described and certain modifica-
28 tions thereof suggested, it will be understood that the t~ue
29 spirit and scope of the invention as set forth in the ap-
pended claims which embrace other modifications and embodi-
31 ments which will occur to those of ordinary skill in the
32 art.
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