US2690275A

US2690275A - High-pressure closure

Info

Publication number: US2690275A
Authority: US
Inventors: Harold M Alt; Westover Oliver
Original assignee: American Locomotive Co
Current assignee: American Locomotive Co
Priority date: 1952-03-22
Filing date: 1952-03-22
Publication date: 1954-09-28
Anticipated expiration: 1971-09-28

Description

Sept. 28, 1954 H. M. ALT :TAL 2,690,275

HIGH-PRESSURE CLOSURE Filed March 22, 1952 HAROLD M. ALT

OLIVER WESTOVER mv'aumns ATTORN Patented Sept. 28, 1954 UNITED STATS PATENT OFFICE HIGH-PRESSURE CLOSURE Harold M. Alt, Dunkirk, and Oliver Westover, Fredonia, N. Y., assignors to American Locomotive Company, New York, N. Y., a corporation of New York Application March 22, 1952, SerialNo. 278,087

the magnitude of several thousand pounds per square inch.

The principal object of this invention is to provide a sealed closure for a high pressure vessel, such as a heat exchanger of the class which functions as a feed water heater. A' further object is to provide such a sealed'closure which may be easily removed from its vessel to permit ready servicing of the interior of the assembly. .Another object is to provide such a closure having sealing means which may be tightened, repaired, or replaced without the neoessity of removing the coverirom the vessel. Another object is to provide sucha closure having a seal so disposed that the elements comprising the means for holding the cover in operative position in the barrel will be kept dry and clear of internal fluids which may cause corrosion or seizing. Still another object is to provide in a heat exchanger of the shell and tube type, a closure construction in which the cover is disposed internally of the shell and is so de-.

,efiectiveness and accommodates itself to relative movement under temperature difierential and expansion. Another object is to provide such a closure in which the cover need have only such thickness as is necessary for pressure requirements and which does not have to extend for-- wardly to the end of the shell to provideouter sealing means. An additional object is to provide a sealing arrangement wherein any outward deflection of the cover caused by hydrostatic pressure which creates a moment at the sealing means is effectively absorbed by a plurality of axial surfaces and thereby resisted by the barrel. Other and further objects of the presentinvention will be apparent from the following description, the accompanying drawings, and the appended claims.

In the drawing:

The figure shows a fragmentary section of the barrel and the head of a heat exchanger vessel of theshell and tube type and of the vessel cover 'arrangedin operative position within the barrel, the joint between the barrel and cover being sealed by gaskets clamped into position by th *novel arrangement oi the invention.

finedby radial wall I5 and axial wall [6.

1y toward the cover.

Referring now to, the drawing, there is shown a fragmentary sectional view of a head for a high pressure heat exchanger of the shell and tube type in which the barrel I0 is formed with .a counterbored shoulder ll against which cover i2 is temporarily positioned when the apparatus is assembled. Cover 12 is formed with a peripheral forwardly facing cut-outportion defined by a radial wall l3 and the axially extending peripheral surface I 4. In this specification, forward denotes the direction toward the open end of the barrel, whereas outer refers to the radially outer portion.

Barrel [0 has an inner cut-out portion de- Radial wall [5 of the barrel is preferably though not necessarily in substantial alignment with radial wall It .of'the cover and isformed with an annular slot lifor the reception of gasket [8. An annular slot l9 is likewise formed in the cover radial wall "[3 for the reception of gasket 2%). Barrel ii) has an internal annular recess formed in wall [6 of the cut-out which is defined by radial side walls 2| and 22 and end wall 23.

Shear ring 24, which is conventionally segmented, comprises a main body having a radial annular flange 25 adapted to fit into the barrel recess 50 that th'ehydro'static load on the cover is transmitted therethrough to the shear bearing wall 22 of" the recess. Said ring also has an axial annular projection 26 extending rearward- Said ring is formed with a longitudinal hole 21 therethrough which is threaded in'it's forward portion but is smoothin its rear'portion. Hole '21 isprovided for the reception of 'set' screw 28. Said set screw is threaded throughout approximately two-thirds of its length adjacent its head, the remainder thereof comprising a smooth shank 29 adjacent its inner extremity. It should be noted that the threaded portion of set screw 28 lies entirely forwardly of shear bearing wall 22. Such a construction isolates the threads from the force lines of hydrostatic compression stress that are transmitted from the cover l2 to shear bearing wall 22. The length of the smooth shank portion 29 of set screw 28 is significant since it provides means of storing internal energy applied to maintaining a positive gasket load and insuring atight joint under all conditions of temperature differential and expansion. Disposed between the shear ring 24 and the peripheral surfacel l vof cover i2 is an integral holding ring 3! which provides radial support for the segments of the shear ring. Ring =3l carries a series of tap bolts 32 which are screwed into cover I2. Ring 3! has a shoulder '33 which fits into cut-out portion 30 formed onthe forward and radially inner corner of shear ring 24. When bolts '32 are tightened; cover l2 and holding'ring 3! are drawn together, and sinceshoulder "33 engagesthe shear ring, the cover and shear ring projection 26 will clamp retainer ring 34 against gasket 20.

Gasket retainer ring 34 is continuous and bridges the joint 35 between barrel Ill and cover I2. It is provided with tongues or flanges 33 and 31 which are connected by a relatively thin strip. Said tongues are adapted for clamping gaskets l8 and into seated position. A solid back-up ring 38 is disposed in the barrel cut-out between projection 26 of the shear ring and wall I6 of the barrel. Ring 38 is formed with a rearwardly facing annular recess defined in part by radial wall 39 for the reception of one end of the gasket retainer ring. Such recess has been found preferable although it is obvious that ring 38 could have a plain wall abutting the retainer ring. Shear ring projection 26 is dimensioned so that its rear face is preferably radially aligned with wall 39 of the ring recess. Back-up ring 33 should be of a hardened material approximately equal to the Brinell hardness of the set screw material so that local yielding of the ring will not occur due to the compressive forces applied to the set screws.

It should be here noted that upon the tightening of set screws 28 against back-up ring 38 the shear ring will be drawn forwardly so that flange will be clamped flush against the shear wall 22. This is significant because there is thus avoided any later shifting of the shear ring forwardly in response to forward movement of cover [2 caused by hydrostatic pressure. Once the flange engages the shear wall, the continued turning of the set screws will serve to force back-up ring 38 against retainer ring 34 to tighten the seal at gasket l8. Shoulder 33 of holding ring 3|, when the tap bolts extending through the latter are screwed into final position, engages shear ring 24 so that cover I2 is drawn toward the shear ring. Projection 26 is then clamped into tight position against retainer ring 34 to clamp gasket 20 into sealing position. It may be advisable, after hydrostatic pressure is applied to the cover, to retighten tap bolts 32. If the cover should shift forwardly, the anchoring pressure of shoulder 33 on the shear ring would be somewhat relieved. Such a condition would be remedied by a re-tightening of the bolts. Thus the shear wall 22 and the sealing surfaces at gaskets l3 and 23 on the barrel and cover re spectively all are designed to be subjected to forces axially of the barrel.

It can be seen from inspection that the hydrostatic load upon cover l2 will be transmitted through gasket 20 and retainer ring 34 to shear ring flange 25 and thence to shear wall 22. If there should be any shifting of the cover forwardly in response to hydrostatic pressure, it will serve to increase the tightness with which gasket 20 is seated. Likewise any deflection of the cover forwardly will serve the same purpose. Upon any such cover shifting or deflection, the design of the retainer ring 34 permits it to be correspondingly deflected. The thin connecting portion provides sufficient flexibility for that purpose.

With the instant invention, the total thickness of cover ill need only be sufficient to meet pressure requirements. The cover need not extend to the forward end of the barrel ID, as is customary in those designs using the method of outer sealing by use of separate rings on the face of the closure. It is also unnecessary to provide tapped holes in the forward end of barrel [0 for bolting and thus the barrel is strengthened.

Inspection holes 42 are located at several locations around the barrel so that leaking due to a defective gasket may be detected. If leaking is observed, then the set screws may be tightened to eliminate the leak.

While there has been hereinbefore described an approved embodiment of this invention, it will be understood that many and various changes and modifications in form, arrangement of parts and details of construction thereof may be made without departing from the spirit of the invention, and that all such changes and modifications as fall Within the scope of the appended claims are contemplated as a part of this invention.

What we claim is:

1. Apparatus of the character described comprising pressure-sustaining barrel having an open end, a cut-out portion in the barrel adjacent its open end, an annular recess in the barrel opening into the cut-out portion, a cover disposed within the barrel and having a peripheral cut-out portion opposite the barrel cut-out portion, a segmented shear ring disposed in said cut-out portions and extending into the barrel recess, a fluid-tight retainer ring rearwardly of the shear ring and spanning the joint between the cover and barrel, a back-up ring between the shear ring and retainer ring, a holding ring to clamp and hold the shear ring in place, a plurality of set screws threaded through the shear ring into abutment with the back-up ring, and a plurality of bolts extending through the holding ring and threaded into the cover, the set screws and bolts independently clamping the retainer ring into seated position to seal the joint between the cover and barrel.

2. Apparatus of the character described comprising a pressure-sustaining barrel having an open end, a substantially axially inwardly facing shear bearing wall in the barrel adjacent its open end, a substantially axially outwardly facing sealing surface on the barrel rearwardly of said bearing wall, a cover within the barrel having a substantially axially outwardly facing sealing surface thereon, a retainer ring spanning the joint between the cover and barrel and seated upon said cover and barrel sealing surfaces, a segmented shear ring abutting the shear bearing wall a holding ring to support the shear ring radially and having overlapping contact therewith, a back-up ring located between the barrel sealing surface and the shear ring, and screw means threaded through the shear ring into abutment with the back up ring to apply force to the back up ring and means threadably engaging the cover and securing the holding ring to the cover to apply force to the cover sealing surface independently of said screw means.

3. Apparatus of the character described comprising a pressure-sustaining barrel having an open end, a shear bearing wall in the barrel adjacent the open end, a forwardly facing sealing surface on the barrel rearwardly of said wall, a cover disposed in the barrel, a forwardly facing sealing surface on the cover in substantially radial alignment with the barrel sealing sur face, gaskets disposed against said sealing surfaces, a retainer ring spanning the joint between the cover and barrel and disposed in contact with the gaskets, a segmented shear ring abutting the shear bearing wall and contacting the re-- tainer ring forwardly of the cover sealing surface, a holding ring supporting the shear ring radially and having overlapping contact therewith, a back-up ring between the shear ring and the retainer ring disposed forwardly of the barrel sealing surface, and screw means threaded through the shear ring into abutment with the back up ring to apply force to the back up ring and means threadably engaging the cover and securing the holding ring to the cover to apply force to the cover sealing surface independently of said screw means.

4. Apparatus of the character described comprising a pressure-sustaining barrel having an open end, a shear bearing wall adjacent the open end, a forwardly facing sealing surface on the barrel rearwardly of said wall, a cover disposed in the barrel, a forwardly facing sealing surface on the cover in radial alignment with the barrel sealing surface, gaskets disposed against said sealing surfaces, a retainer ring spanning the joint between the barrel and cover and disposed in contact with the gaskets, a segmented shear ring abutting the shear bearing wall and contacting the retainer ring forwardly of the cover sealing surface, a back-up ring between the shear ring and the retainer ring disposed forwardly of the barrel sealing surface, a holding ring to radially support the shear ring, a plurality of bolts threaded into the cover to retain the holding ring against the shear ring, and a plurality of set screws threaded into the shear ring and extending therethrough into aJbutment with the back-up ring to clamp the latter against the gasket retaining ring thus to clamp the barrel gasket into position.

5. Apparatus of the character described comprisin a pressure-sustaining barrel having an open end, a forwardly facing sealing surface, and a cut-out portion extending forwardly from said surface to the open end of the barrel; an annular recess in the barrel wall opening into the cut-out portion of the barrel to provide a rearwardly facing shear bearing wall; a cover in the barrel having a forwardly facing sealing surface in radial alignment with the barrel sealing surface and a cut-out portion extending from the cover sealing surface to the forward face of the cover; gaskets upon the sealing surfaces; a retainer ring spanning the joint between the cover and barrel and having tongues positioned against the gaskets; a segmented shear ring having a flange extending into the barrel recess; a projection extending rearwardly from the shear ring to contact the retainer ring opposite the cover sealing surface; a back-up ring between the shear ring and retainer ring opposite the barrel sealing surface; a holding ring extending into the cover cut-out portion to hold the shear ring in radial position; a plurality of bolts extending through the holding ring and threaded into the cover to draw the cover toward the retainer ring to tighten the cover gasket; and a plurality of set screws threaded into the shear ring and extending therethrough into abutment with the back-up ring to clamp the latter against the gasket retainer ring thus to clamp the barrel gasket into position.

6. Apparatus of the character described comprising a pressure-sustaining barrel having an open end, an interior outwardly facing sealing surface on the barrel, a cut-out portion extending from said surface to the end of the barrel, an annular recess opening into the cut-out portion thus providing an inwardly facing shear bearing wall, a cover in the barrel having a forwardly facing sealing surface in radial alignment with the barrel sealing surface and a cut-out portion extending from said cover sealing surface to the outer face of the cover, gaskets disposed against the sealing surfaces, a retainer ring spanning the joint between the cover and barrel and engaging the gaskets, a segmented shear ring having a flange extending into the recess to engage the shear bearing wall, a rearwardly extending projection on the shear ring engaging the retainer ring opposite the cover sealing surface, a backup ring between the shear ring and retainer ring opposite said barrel sealing surface, a holding ring partially overlapping the shear ring, a plurality of bolts threadably anchored in the cover to hold the holding ring in supporting position against the shear ring, a plurality of set screws threadeJbly mounted in the shear ring and extending through the latter into abutment with the backup ring, said bolts and set screws being adapted to exert independent pressure on the retainer ring opposite the gaskets.

7. Apparatus of the character described comprising a pressure-sustaining barrel having an open end, an annular recess in the barrel having a shear bearing forward wall, a cover disposed within the barrel, a forwardly facing sealing surface on the barrel, a forwardly facing sealing surface on the cover, the latter sealing surface being in substantial radial alignment with the former, a gasket on each sealing surface, a retainer ring spanning the joint between the cover and barrel and contacting the gaskets, a segmented shear ring between the cover and shear bearing recess wall, said ring having a portion in contact with the retainer ring axially opposite the cover gasket, an integral ring to support the shear ring radially, a back-up ring between the shear ring and the retainer ring axially opposite the barrel gasket, a series of screws supported by the shear ring and abutting the back-up ring, said screws being adapted to clamp the back-up ring against the retainer ring thus to tighten the barrel gasket, and a series of bolts screwed into the cover adapted to draw the cover toward the retainer ring to tighten the cover gasket.

8. Apparatus of the character described comprising a pressure sustaining barrel having an open end, a substantially axially inwardly facing shear bearing wall in the barrel adjacent its open end, a substantially axially outwardly facing sealing surface on the barrel rearwardly of said bearing wall, a cover within the barrel having a substantially axially outwardly facing sealing surface thereon, a retainer ring spanning the joint between the cover and the barrel and seated upon said cover and barrel sealing surfaces, a segmented shear ring abutting the shear bearing wall, a back-up ring disposed between the barrel sealing surface and the shear ring, screw means threaded through the shear ring into abutment with the back-up ring to apply force to said back-up ring, and means cooperatively engaging said shear ring and having a threaded connection with said cover for independently applying force to the cover to draw said cover toward said retainer ring.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 2,203,364 Rathbun June 4, 1940 2,296,620 Tinker Sept. 22, 1942 2,342,186 Fischer Feb. 22, 1944 2,545,290 Long Mar. 13, 1951