CA1110495A - Combination tank car valve skid and valve seat - Google Patents

Abstract

ABSTRACT OF THE DISCLOSURE

In a bottom operable tank car lading valve assembly, a combination skid and lading valve seat for the lading valve closure is provided, which is attached to the tank car universal flange with mechanical fasteners. The valve seat portion extends inwardly and upwardly from the universal flange and includes a machined seat. The skid portion extends upwardly and outwardly from the universal flange, forming a circumferential taper, and the upper portion abuts the bottom of the tank. The skid portion protects the lading valve closure and the lading valve seat against impacts which might normally cause unseating of the valve closure and escape of the lading in the absence of the skid portion.

Description

Recent Associations o ~merican Railroads tAAR) and Department of Transportation (DOT) railway tank car regulations for stub sill cars require that projections extending below the tank bottom in excess of one (1) inch must be protected by a skid. It is recommended that the skid have a three unit longi-tudinal dimension along the bottom of the tank for each one unit of downward projection from the bottom oE the tank. The outer end of the skid is connected to the tank with fasteners which do not require stress relieving of the tank body.
One proposed skid design comprises a conical shaped skid welded to the bottom of the tank~ tapering downwardly from the tank bottom to a slope of 3:1 and having a center opening where the lading valve is located for unloading of the lading. How-ever the skld i~ welded to the ta~k bottom outboard o~ the universal flange found on presently used tank cars. l'his is disadvantageous because the weld to the tank bottom requires stress relieving, and the skid adds weight to the car with no functional benefit to the car other than outlet valve protection.
In U.S. Patent 928,924 (1909) a tank car is disclosed in which castings C and D are mounted in the through center sill A
and part o the casting C serves as a valve seat Eor the lading valve E. Cast~ng C i~ tapered downwardly and outwardly away from the lading valve toward castings D. The through center sill and castings C and D would inherently provide some protection for the lading valve seat and lading valve closure.
However the through center sill design adds weight to the car in contrast to a stub sill tank car, and the taper on the castings C tends to direct obstructions into -the lading valve seat and valve closure, rather than away from the valve seat and valve closure.
The object of the present invention is to pr~vide a tank car combination valve seat and ski~ design for stub sill cars which complies with the above A~R and DOT Regulat:ions, which can be readily attached to existing stub sill tank cars without welding to the tank bottom and which adds little weight to the car.
In a bottom operable tank car lading valve assembly, a combination skid and lading valve seat for the lading valve closure is provided, which is attached to the tank car universal flange with mechanical fasteners. The valve seat portion extends inwardly and upwardly from the universal flange and includes a machined seat for the valve closure. The skid portion extends upwardly and outwardly from the universal flange, forming a circumferential taper, and the upper portion abuts the bottom ~ -of the tank. Fasteners connect the upper portion of the tank bottom which do not require stress relieving of the tank. The skid portlon protect9 the ladinc~ ~lve closure and the lading ~alv~ 3~at against imp~ct~ which might normally cause ~mseatincJ
of the valve closure ~nd escape oE the lading in the absence o~
the skid portion. The valve seat portion may include additional machined surfaces which are required for the raising and lowering of the valve closure. The valve seat portion, body portion and skid portion may be formed from a single member, or the skid portion may be welded to an integral valve seat portion and body portion. The skid portion preferably includes longitudinally e~tending webs separated by void spaces to sav~ weight. ~ depen-ding lading valve housing including a lading outlet may be attached to the combination valve seat and skid with fasteners which constitute a shear plane for the valve housing. A housing may include a lower operator for the valve closure~ Alternatively the valve closure may be top operated. In another alternative fasteners constituting a ~hear plane may be used to attach a valve guard which protects the valve closure in transit and to which an adapter having a lower operator to operate the valve closure may be attached at destination for loading and unloading the lading.

. ,:

The ~rawing 5 Fig. l is a vertical sec~ional vie~ illustrating the combination skid and valve seat of ~he present invenkion, looking in the ~irection o~ the arrows along the line :L-l in Figure 2;
Fig. 2 is a bottom view looking in the directlon of the arrows along the line 2-2 in Fiyure l;
Fig. 3 is a vertical sectional vie~r lookinc3 in the direction of the arrows along the line 3-3 in F~gure 2;
Fig. 3A is a partial bottom view of a modification of the arrangement shown in Fiyures l - 3;
Fig. 3B is a partial vertical sectional view looking in the direction of the arrows along the line 3B~3~ in Figur~ 3A;
Fi~. 3C is a part~al v~rtica~ ~ectional V:i~!W :look:in~
in the direction o~ ~h~ arrows alony the l:ine 3C-3C :in Figure 3B;
Fig. 4 is a partial vertical sectional view illustrating an alternative embodiment of the combina~ion skid and valve seat o~ the present invention;
Fig. 4A is an enlarc~ed vertical sectional view illustr~t:ing still another embodiment;
Fig. 5 is a perspectiv~ vi~w, partly ~.n section, illustrating a depending outlet housincJ attachecl to the com-bination skid and valve seat of the present invention, in which the housing includes a lower operator for raisiny and lowexing the valve closure.
D`escription o~ Preferred Embodiments In caccordance with the present invention a combination skid and valve seat is indica-ted in the drawings generally at lO. The combination skid and valve seat includes a cJellerally cylindrical bodY portion 12 haviny openin~s t}1erein l4 ~h;ch are coun~ersun1c. ~olts l6 a~tach the combination s1cid antl valve ` seat l:o a cLrcular univers~al tank car ~1al1cJe 18 l1av:inc~ drilled, ~ .

95i threaded openings 18a. The universal flange 18 is welded to the tank bottom 20 in -the usual manner.
The combination skid and valve seat includes a valve seat portion 22 which extends inwardly and upwardly from body portion 12 within universal flange 18. The valve sea-t portion 22 includes a machined valve seat 24 which is tapered inwardly upon which a valve closure 26 seats in closed position to maintain lading within the tank.
The design of the particular valve closure is not a part of the present invention except that the valve closure and the valve seat 24 must be compatible to provide a seal to maintain the lading in the tank. ~he valve closure may be operated from the top o~ the -tank or ~rom the bottom o:E the tank. ~ kop operated valve c.Losure is d:isclosecl in the a.Eore-mentloncd U.S. Patent 9~,92~. Many other top operated vaLve closure des:Lgns exist in the patent art and/or which are commercially available.
A bottom operated valve closure ls disclosed in U.S.
Patents 3l981,481; 4,141,535 and 4,124,193 and assigned to the same assignee as the present application. An improved design is found in U.S. Pa-tent 4,158,453, also assigned to the same assignee as the present applicat.ion. The valve closure in these arrange-ments can be removed w~th lading in the tank :Eor repair orreplacement as described in U.S. Patent 4,161,958.
The valve seat portion 22 may require ad~itional machined surfaces to accommodate an operator 27 for the particular closure member. For e~ample, if the aforementioned valve closure described in U.S. Patent 4,158,453 is utilized, a lower vertical machined surface 28 is provided including a plurality of spaced slots 30 for the attachment of a valve closure .i .
''' i ~

S

retainer 32 (Figure 5) having projections 34. Furthermore a circumferential guide surface 36 is provided to guide vertical movement of a depending portion 38 of the valve closure as the valve closure moves between open and closed positionO A stop 39 is provided to cease vertical movement of the valve closure 26 when it has assumed the full open position. It is to be emphasized, however, that the particular machined surfaces to be provided on khe valve seat portion will depend upon the constxuction of the particular valve closure and valve operator utilized. Thus the additional machined surfaces described and illustrated are by way of example only, and should not be considered as limiting.
The combination skid and valve seat further includes a skld portion indicated in the drawings ~enerally at: 40. The skicl portion extends upwardly and outwardly from the bod~
portion 12 on opposite sides as indicated at 41 and 41'. The end portions 42, 42' abut the bottom of the tank 20. While it is possible to construct the skid portion 40 of a large solid member, it is preferred to use the web construction illustrated in Figures 2 and 3 to save weight. This web construction includes webs 4g, 46, 48 and 44', 46', 48' located respectively on opposite sides of the valve seat portion 22. Between webs 4~, 46 and 44', 46' are respective vo:ids 45 and 45'. Similarl~
between webs 46, 48 and 46', ~8' respective voids 47 and 47' exist. Webs 44, 46, 48 and 44', 46', 48' terminate in ski.d end -portions 42 and 42' adjacent the bottom of tank 20. End portions 42 and 42' are curved as indicated at 42a and 42a' to avoid a projectlng surface. The curved end portions 42a and 42a' preferably do not extend more than one (1) inch to meet AAR and DOT requirements for vertical projections below the tank bottom.

Skid portions 41, 41' are preferably constructed wi.th ~1$495 a 3:1 longitudinal to vertical slope to comply with the above described AAR and DOT RegulationsO It will be noted, however, that the skid end portions 42 and 42' merely abut the bottom of the tank. They are not welded thereto and thus stress relieving of the tank is not required. Curved end portions 42a and 42a' and the taper of the s~id reduce the like:Lihood that if the tank or the combination skid and valve seat is impacted, the portion of the impact loads transmitted to valve seat 24 and valve closure 26 will be of sufficient magnitude to cause unseating of valve closure 26 and escape of the lading.
It is a simple operation to attach the combination skid and valve seat to existing tank bottoms. All that is necessar~ is to drill the threaded openings 18a into the universal flange 18~ if the holes ~re not already in the Elanges.
The combination skid and valve seat can then be attached to the universal flange by inserting fasteners 16 into countersunk openings 14 in the combination skid and valve seat.
As shown in Figures 3A - 3C in an alternative con-struction, openings 43 may be provided in end portions 42, 42' and threaded studs 43a welded to the tank bottom. Fastening nuts ~3b may then be attached to hold the skid portion in engag~ment with the tank bottom 20.
Body portion 12 further includes connecting means indicated generally at 50 (Figures 2 and 5) ~or attaching to the combination skid and valve seat to a depending member including a lading outlet which may include a bottom operator for the ~alve closure. The connecting means 50 may include a plurality of openings 52 (Figure 2) located around the same bolt circle as openings 14 but circumferentially spaced therefrom. Four are illustrated in ~igure 2. Openings 52 may be used to attach a dapending housing 138 or outlet chamber shown in ~igure 5.

Openings 52 may also be utilized to connect the combincltion skid and valve seat to a valve guard as described in Reedy U.S. --Patent 4,121,614~ which protects the valve closure in transit and wherein an adapter is attached at des-tination to load and unload the lading. A sui-table adapter is described in Reedy U.S. Patent 4,137,937. U.S. Pakent 4,12:L,614 and 4,137,937 are assigned to the same assiynee as the present application.
An example of the depending housing 138 containing a bot~om operator for closure member 26 will be described hereinaft:el.
Another embodiment of the present invention is illustrated in Figure 4. In this embodirnent a combinati.on s~id and valve seat 60 includes a generally circular body portion 62 having countersunk openings 64 into which fasteners 66 are inserted to attach the combination skid and valve seat to a univ~rsal ~lanye 18 ~ttached to a l:ank bottom 20 hy weld:ing, ancl h~lv.iny threaded op~n.ings l~a. F.iyure~ ~ al--:o i.llusl:ral:es a tonc~ue 19 on uni~exs~ll flarlye 18. Bod~ port.ion 62 :inc:ludes a circular slot 63 into which is inserted a gasket seal 65.
Figure 4 illustrates that for retrofit, openings 68 in the ;
universal flange may be filled with fillers 70 as part o~ a retrofit opera-tion.
The combination skid and valve seat 60 includes a valv~ ~at portion 72 wh:ich extencls upwarclly and :inwardly from body portion 62 within univ~-~rsal ~lang~ 18. ~ machined valve seat 7~ is provided upon which seats a valve closure 76 in closed position. As described above machined surfaces 78, 80, 82 and shoulder 84 may be provided as are necessary for the operation of the particular valve closure utili.zed, and described in greater detail hereinafter relative to Fiyure S.
In this embodiment fasteners 85, constituting a shear plane, are shown holding in place a dependin~ valve c~uard 86 , '~.:`j , .
-- .

.ncludin~ a ~lanye portion 86a alld ~In in-ternally threc-lded portion 87 into which i5 insert~d a transverse plug 88 havil~y a protective protrusion 88a. A removable pluy 88b is also provided as described in detail in said U.S. Paten-t 4 121,614. A connecting seat on contour ~9 is also provided to receive an adapter (not sho~m) cons-tructed according to the teachi:ngs of U~S. Paten-t .
~,137,~37.

Ho~7ever it is to be understood that f~steners 85 rnay also be used to attach a depending housing 138 (Figure S~ including a lading outlet 139 and a bottom operator 141.
Also in this embodiment the skid portion 90 comprises a circular plate 92 wh~ch is curved as indicated in dotted lines .
.at 93 to follow the tank curva-ture, attached to body portion 62 with a weld 9~. As described in the embodiment shown .in F.i~ur~c~ 1 throuc~h 3, plat~ 92 :is prc~EerEIbly o~ ~ len~h to prov:id~ th~ 3:]. lo~ itud.irlal to vert:.ic:cll s:l.op~ reclu.i.red by tho ~R and DOT. W~].d 9~ :is preEcrclbly a fi.llet we:Lcl and :i.n whlch I plate 92 is cut away at 95 to facilitate making this fillet ~eld.
The end portion 96 oE circular plate 92 is preferably curved at 97 and abuts the tank bottom. Preferably curved end portion 97 does not e~tend more than one (1) inch below the tank bottom to meet ~AR and DOT requirements.
This cmbodiment has the advantage tha-t ~x:i.st.ing flange and vcllve seat members o~ the type describ~d in U.S. Patcnt ~,:lS8,453 ref~rred to above can be provided w.ith a skid by merely welding in place a curved plate 92. Thus existing tank cars having the bottom operable closure disclosed in U.S. Patent 4 158-453 can be re~dily retrofitted by attaching plate 92 to provide a skid portion and comply with the AAR and DOT regulations.
An altexnative arrangement is shown in Fi~ure 4A~ A plate 100 may be welded to the tank bottom 20 and unive.rsal flange 18 at 100a, and at 100b prior to welding in place the p:late 92 .
Then plate 92' may be welded at 94' ~o a bod~ portion 62 and to . 8 ,''',1 . .
,.,,, :

plate 100. Weld metal 102 may then be utilized to provide a curved tapered portion 104 so that impact loads will be ~irected downwardly along plate 92' rather than upwardly into the valve seat portion to cause unseating of the valve closure, or upwardly into the tank, and increasing the likelihood of puncturing the tank. This construction does require stress relieving of the tank where plate 100 is welded to the tank. Furthermore, after initial assembly, valve closure 76, seat 76a and keeper 76b must be removed from inside the tank. The remaining parts can be removed from outside the tank as described in U.S. Patent 4,158,453 referred to above.
Figure 5 illustrates a lading valve assembly including the combination valve seat and skid of the present invention with a depending housing 138 attache~ to the comb:i.nation skid and valve ~t body portion 12. Dependiny housing 138 is att~ched to body portion 12 with ;E~ten~rs ~ . Fast~n~rs :L~0 ext~nd into open-ings 52 located between fasteners 16 (Figure 2). Fasteners 140 constitute a shear plane whereby housing 138 will shear off upon impact. Housing 138 includes a lading outlet 139 having a cap 139a and a depending operator 141 having a lower tool connection portion 141a, a cap 141b, seals 141c and an upper portion 142 which engages a cooperating portion 144 oE operator 27. Upper operator 27 is maintained in position, spaced from the walls of the valve seat portion 22, by retainer 32 which engages the mach-ined surfaces 28 and located within slot 30 described above.
Mote projections 34 of retainer 32. Retainer 32 engages at 134 a shoulder 132 and a split collar 133 on operator 146. Operator 146 is internally threaded at 148 and a depending operator 150 is externally threaded. Operator 150 is held in place by means of a depending member 152 held in place engaging closure 26 by fasteners 154. Depending member 152 includes a portion 156 that maintains a seal 158 in place. In closed position seal 158 seats on valve seat 24. Details ,, of the closure and seal arrar~ rnen~ are ~scribed in U.S. Patent 4,161,958 reEer~ecl-to a~ove.
~ ith housing 138 in place, CclpS 139a and 141b may be removed and a suitable tool attached to the lower por~ion 14la o-E operator 141 to ro-ta-te operator 141. This in tu~n rotates operator 144.- Depending member 152 includes arms 38 which engage retainer ribs 32 after initial rotation of operator 146.
After engagement of arms 38 and retainer 32 the closure m~mber 26 is movable vertically to the open position. Rotation in the opposite direction lowers it to the closed, seated posi-tion on valve seat 24.
As mentioned above, fasteners 140 constitute a shear plane.
If housing 138 is impacted, the fasteners will shear off and the housiny and the operator 1~1 wil1 clxop off. Note clearance between memb~rs 1~2 and 1~. Thus clo3ure m~mber 26 wiLl remair in -~h~ closed, seatetl pos:i~.ion ov~n iE holls:ing 13U :is imp(lck~!cl and is sheared of~.
If skid poxtion ~0 is impacted, the vertical impact loads tend to be directed into the massive tank body, with lit-tle ;
tendency to unseat valve closure 26. Hori~ontal components are directed into universal flange 18 which tends to protect valve seat portions 2~ and 72 (Figure ~) from these horizontal impact locl~ls .
~ f the t~nk has b~conie unsacldl~cl rom i.t5 truck, for example in derailmentr and -the tank is skidding along the ground, the s]cid tends to keep the tank moving and avoids impact loads which might result from the universal flange, without a skid, abutting a solid, rigid object in its path. The depending housing 138 or valve guard 86 (Figure 4) may be sheared oE~ as the tank skids along, but the likelihood -that the vc~lve closure will become unseated is signiicantly xeduced wi-th -the combination skid and valve seat of the present invention.
The embodiments shown in Figures ~ and 4A Eunclion in a '' s similar manner.
It will thus be apparent that the combination skid and valve seat of the present invention is readily attached to the existing universal flange of the tank car by mechanical fasteners, and in Figures 4 and 4A by welding. The skid slope may be fabricated to comply with the 3:1 longitudinal/vertical projection ratiorequired by current AAR and DOT Regulations. In the embodiment shown in Figures 1 - 3 and 5 no welding is required to the tank body, thus avoiding stress relieving.
Providing weld metal 100b in the embodiment shown in Figure 4A necessitates local stress relieving. However for some applications, such stress relieving may be preferred in a retro-fit operation to provide skids on exist.ing tank cars which comply with ~AR and DOT requiremerlts.

Claims (28)

THE EMBODIMENTS OF THE INVENTION IN WHICH AN EXCLUSIVE PROPERTY
OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:

1. In a bottom operable tank car lading valve assembly, a combination skid and lading valve seat for the lading valve closure comprising:
a generally circular body portion having first openings for attaching the combination skid and valve seat to a tank car universal flange with mechanical fasteners, a valve seat portion extending inwardly and upwardly from said body portion and including a machined seat; a skid portion extending upwardly and outwardly from said body portion forming a circumferential taper; the upper portion of said skid portion abutting the bottom of the tank; whereby said skid portion protects said lading valve closure and said lading valve seat against impacts which might normally cause unseating of the valve closure and escape of the lading in the absence of the skid portion.

2. A combination skid and valve seat according to claim 1 wherein said upper skid portion is curved in the area where it abuts the tank bottom.

3. A combination skid and valve seat according to claim 1 wherein said valve seat portion, body portion and skid portion are formed in a single member.

4. A combination skid and valve seat according to claim 3 wherein said single member is a casting.

5. A combination skid and valve seat according to claim 1 wherein said skid portion comprises a plate welded to said body portion.

6. A combination skid and valve seat according to claim 1 wherein said body portion comprises fastening means for attaching a depending member including a lading discharge spout.

7. A combination skid and valve seat according to claim 6 wherein said fastening means comprises second openings circumferentially spaced from said first openings.

8. A combination skid and valve seat according to claim 1 wherein said skid portion includes a plurality of longitudinally spaced webs and wherein void spaces exist between said webs.

9. A combination skid and valve seat according to claim 1 wherein said valve seat portion includes at least one additional machined surface which is utilized in moving said valve closure between open and closed positions.

10. A combination skid and valve seat according to claim 1 wherein said skid portion is connected to said tank bottom with skid portion fastening means.

11. A combination skid and valve seat according to claim 10 wherein said skid portion fastening means comprise studs welded to the tank bottom extending through openings in the skid end portion.

12. In a bottom operable tank car lading valve assembly, a combination skid and lading valve seat for the lading valve closure comprising:
a generally circular body portion having first openings for attaching the combination skid and valve seat to a tank car universal flange with mechanical fasteners; a valve seat portion integral with said body portion and extending inwardly and upwardly from said body portion and including a machined seat; a skid portion integral with said body portion and extend-ing upwardly and outwardly from said body portion forming a circumferential taper; said skid portion including a curved end portion abutting the bottom of the tank; whereby said skid portion protects said lading valve closure and said lading valve seat against impacts which might normally cause unseating of the valve closure and escape of the lading in the absence of the skid portion.

13. A combination skid and valve seat according to claim 12 wherein said skid portion includes a plurality of longitudinally extending, transversely spaced ribs extending from said body portion to said end portion.

14. A combination skid and valve seat according to claim 13 wherein void spaces exist between said ribs.

15. A combination skid and valve seat according to claim 14 wherein a pair of side ribs and a center rib are provided on either side of said body portion,

16. A combination skid and valve seat according to claim 12 wherein said combination skid and valve seat is a casting.

17. A combination skid and valve seat according to claim 12 wherein said skid portion is connected to said tank bottom with skid portion fastening means.

18. A combination skid and valve seat according to claim 17 wherein said skid portion fastening means comprise studs welded to the tank bottom extending through openings in the skid end portion.

19. A combination skid and valve seat according to claim 12 wherein said body portion includes second openings circumferenti-ally spaced from said first openings having second fasteners extending therethrough which constitute a shear plane which fasteners hold in place a depending member including a lading discharge spout.

20. A combination skid and valve seat according to claim 19 wherein said depending member is a depending housing including a bottom operator for said valve closure.

21. A combination skid and valve seat according to claim 20 wherein said valve seat portion includes a plurality of machined surfaces which are engaged by the operator for said valve closure.

22. In a bottom operable tank car lading valve assembly, a combination skid and lading valve seat for the lading valve closure, comprising:
a generally circular body portion having first openings which attach the combination skid and valve seat to a tank car universal flange with first mechanical fasteners; a valve seat portion integral with said body portion and extending inwardly and upwardly from said body portion and including a machined seat; a skid portion welded to said body portion and extending upwardly and outwardly from said body portion forming a circumferential taper; the upper portion of said said portion abutting the bottom of the tank; whereby said skid portion protects said lading valve closure and said lading valve seat against impacts which might normally cause unseating of the valve closure and escape of the lading in the absence of the skid portion.

23. A combination skid and valve seat according to claim 22 wherein said skid portion comprises a pair of curved plates longitudinally spaced and each welded to said body portion.

24. A combination skid and valve seat according to claim 23 wherein said curved plates include a curved end surface which abuts the bottom of the tank.

25. A combination skid and valve seat according to claim 24 wherein at least one additional curved plate is welded to said body portion and which extends longitudinally away from said body portion including a distal end portion which is welded to said tank bottom and to the outer surface of said first curved plate.

26. A combination skid and valve seat according to claim 25 wherein weld metal is provided between the tank bottom and said second curved plate and between said first curved plate and said second curved plate to provide a smooth, generally curved skid end portion.

27. A combination skid and valve seat according to claim 22 wherein said body portion includes second openings circumfer-entially spaced from said first openings having second fasteners extending therethrough which constitute a shear plane which fasteners hold in place a depending member including a lading discharge spout.

28. A combination skid and valve seat according to claim 27 wherein said depending member is a valve guard including a transverse plug which protects said valve closure in transit and further includes an external contour to receive an adapter to load and unload the lading at destination.