FR2534658A1 - BALL VALVE FIREPROOF - Google Patents

Abstract

FIRE PROOF BALL VALVE. IT INCLUDES A BODY 10 INCLUDING A CENTRAL PASSAGE 20, A BALL C PLACED IN THE PASSAGE 20, AND TWO SHOULDERS EXTENDING RADIALLY INTO THE PASSAGE ARRANGED ON CIRCUMFERENCES OF THIS ONE ON EACH OTHER OF THE BALL. THE BALL INCLUDES AN OPENING 15 FOR FLUID CIRCULATION. SEAT B INCLUDES A 100 RIGID REINFORCEMENT RING, 102 REINFORCEMENT REINFORCEMENT RING 102 SUPPORTED BY 100 REINFORCEMENT RING AND PROVIDES FOR FLUID-TIGHT ENGAGEMENT WITH BALL C, AND A RESISTANT 104 SECONDARY SEAT RING THE HEAT INTERPOSED BETWEEN THE ELASTIC SEAT RING 102 AND AN ASSOCIATE OF THE TWO SHOULDERS 70. A STOP RING IS PLACED IN THE SEAT RING. IF DAMAGE CAUSED BY FIRE TO ELASTIC SEAT RING 102, SECONDARY SEAT RING 104 ENGAGES WITH BALL C TO CLOSE THE VALVE. RETURN RING 130 PREVENTS SEAT RING 102 SPINNING, SO THE SEAT ASSEMBLY MAINTAINS A SEAL IN THE EVENT OF PARTIAL DESTRUCTION OF THE ELASTIC SEAT RING 102.

Description

This invention relates to a valve, and more particularly to a valve

fire resistant

or fireproof.

  When it comes to a valve, the term "fireproof" means that this valve meets certain specific conditions when it is subjected to a fire. See for this Arant, "Fire-Safe Valves An Overview", in the minutes of the thirty-sixth annual symposium on instrumentation in

  industrial processes (Texas A & M University, 1981).

  Unfortunately, different sets of conditions have been promulgated by different organizations and the valve industry has not yet recognized a uniform standard Basically, according to one of the

  standards (American Petroleum Institute 607), a

  pope which remains hermetic in the closed position for at least ten minutes, the valve body being at a temperature of not less than 5930 C, may be certified "fireproof" A valve that has been designed in such a way that flee under the action of fire but that does not meet these standardized specifications is

  commonly called "fire resistant".

  The invention is particularly applicable to a ball valve with a flexible seat and a valve seat

  new and improved firefighting, for a

  pope of the type with what is called a "floating ball", and will be described in particular by

  reference to this type of valve However, it becomes

  For those skilled in the art, it is clear that the invention can find wider applications and could be adapted for use in other types and styles of valves. For the construction of ball valves used in the trade,

  annular seats made of a plastic material

  bind and deformable like Teflon (trade mark registered by E I Pont de Nemours and Company) for

  to engage hermetically with the ball Two

  Such balls are arranged against the inlet and outlet openings of the valve. The ball itself is mounted so as to be able to move slightly in the direction of the axes of the seats when the valve is in the closed position under the valve. fluid pressure action Such a displacement causes the ball to press down and deform the annular downstream seat, thus improving the hermetic engagement of the ball and the seat against each other. The degree of sagging varies depending on the fluid pressure

Implementation.

  When subjected to a fire, the registered seat

  the soft surface of a ball valve of a conventional type

  The floating ball is substantially damaged by the heat of the fire to the extent that leakage through the valve can become unacceptable. Typically, downstream of the ball, the seat destruction sequence is as follows: the plastic softens first, then begins to sink or spin through the valve orifice. Further prolonged exposure to heat

  excessive causes the combustion and sublimation

  The destruction of the plastic seat allows the ball to move farther under the pressure of the fluid, until it

  engages with a secondary seat Such a secondary seat

  typically comprises a projection extending radially inwardly of the valve body, made of metal or non-flammable material, such as a supporting shoulder for the plastic seat. Normally, such a surface is not specifically designed for engagement. very hermetic with the ball, and gives

to substantial leaks.

  Another particular problem appears

  when the plastic seat is destroyed only in

  For example, when a valve is exposed to the radiant heat of a single-sided fire, or in a low-intensity fire, it may be that only the portion of the valve seat nearest the

  fire is softened and runs through the

  pope The ball can then move under pressure

  fluid to this surface left free by extrusion.

  and, not being able to engage regularly with the secondary seat, leave free a large leakage passage Or again, the ball may be prevented from coming into contact with the secondary seat by the

  parts of the plastic seat and thus left

  free, again, important leakage

  In both situations, the fuide can be

  cipitate through the fluid passages and cool

  suddenly the valve The cooling action -

  tends to prevent further deterioration of the seat despite a prolonged fire, and

  typically a massive leak through the valve.

  An additional but unrecognized problem that arises during a fire is the rapid increase in the pressure of the heated fluid enclosed between the inlet and outlet seats, around the ball. The heat-fire can heat-and even spray this

  fluid in the center of the valve, between the seats Sou-

  wind, the fire is so intense that the fluid vaporizes too quickly to be able to escape quickly behind the seats and avoid an excessive increase

  pressure inside the valve. Such an increase

  pressure can easily exceed the

  quoted from the valve and break the seals in the mounting of the stem and the seals of the valve body, or break

the valve body itself.

  Another practical problem is when

  that a fire hydrant is directed at a valve containing a volatile liquid, which has been heated by a fire The rapid cooling action of the water from the fire hydrant causes violent condensation of the heated vapor in the valve, which dislodges the ball and stirs ash or debris that can become lodged between the ball and the surface engaging with the ball, thus causing leakage passages

additional.

  A general objective of fire and fire resistant ball valve seat design is to provide a valve that is hermetic under normal operating conditions with conventional materials, and that is also airtight when has been subjected to fire Until now, different types and different forms of ball valve seats have been proposed and used in the industry for the purpose of obtaining a fire-resistant valve or

  fireproof, with varying degrees of success.

  It has been found that the defects presented by most

  previous designs of resilient ball valves

  fire-proof QUANTANTS are such that the devices themselves are of value

practical and economical limited.

  A common type of fire-resistant ball valve includes a flexible primary seat made of plastic material such as Teflon, and a secondary seat made of metal or composite material at high temperature to seal the valve after destruction.

  of the primary seat in a fire The secondary seat

  typically takes a rim or an interposed washer

  between the plastic primary seat and a supportive shoulder

  Valve Body Wear This design suffers from problems that naturally result in any type of metallic metal contact clogging. Since the ball is never perfectly spherical and the metal secondary seat is not perfectly circular, the ball can not enter a metal. perfect ring contact with the metal seat and leaks through the secondary seal are usually important after the

  destruction of the primary seal For a metal seal

  metal is almost everywhere waterproof in a

  fireproof or other type, the surfaces joined together

  They must be adapted by running-in or burnishing, one over the other. Such a procedure is very expensive.

  burn-in adaptation is an economic procedure-

  impractical for a valve manufacturer to

  fire-resistant or fire-resistant Moreover,

  a mechanically adapted secondary seat would be

  to be scuffed by the hazards and consequences of normal valve operation, such as corrosion, stinging, scaling, erosion and so on.

  that during a fire the advantages of the mechanical adaptation

  Ball Valves with a secondary seat of high temperature metal or composite material also suffer from problems of partial destruction and rapid cooling of the primary seat, as well as problems of insertion of ashes and associated debris. at fast cooling. A proposed improvement over the design of the secondary metal seat consists of

  add a secondary seat made of a resistant material

  heat that is more deformable and more

  link that metal Typically, we used rings

  in carbon or graphite, although such models can

  ensure improved functioning when they are

  new, these models have been found to be particularly

  subject to deterioration during normal operation.

  Normal wear during valve open-close cycles, erosion on opening, or abrasion by foreign matter can easily damage

  the secondary seat materials that are typical-

  Thus, such designs generally still include a metal rim as a final or tertiary seat to reduce leakage if the secondary seat is damaged. Such a multiplication of seats increases the size, complexity and cost of the valve without adding a reliable redundant shutter Any element of wear, erosion or foreign matter that can damage one of the seats can also damage all seats since they are

  also rested in normal service.

  Another proposal to get a valve

  is to include a

  in a sufficiently insulating lining to isolate the valve for a time sufficient to exhibit a "fireproof" behavior Another proposal is to have a sprinkler near the valve that can quickly cool the valve during a fire These two solutions unsuitable for practical cost reasons, as they result in costly installation and maintenance.

  an isolated valve would suffer from the problem of

  study on re-installation or correct installation

  insulation at each maintenance of the valve.

  Therefore, it has been sought to develop a ball valve and a fireproof seat assembly that functions properly under conditions

  of normal operation and also that hermetically sealed

  The valve in a closed valve position, when exposed to fire, would preferably eliminate such need for expensive sprinklers or insulating gaskets to protect the valve.

  The present invention consists of a construction

  new and improved approach that eliminates all the problems

  my cited above and others, and provides an improved and fireproof floating ball type valve and seat assembly which exhibit

  improved shutter capabilities and resists

  leaks when they are exposed to

  The invention can furthermore be useful for a wide range of seating and material models that can effectively close in a

  wide range of normal operating conditions.

  In general, the present invention relates to a ball valve and a seat assembly

  new and improved fire-proofing

  a composite seat assembly comprises a flexible plastic primary seat or ring, and a secondary seat element in a heat-resistant deformable material The secondary seat element seals the valve in case of partial or complete destruction of the ring primary seat under the effect of fire or

  extreme heat Two assemblages of this type are

  placed on either side of the ball and are pushed

  permanently to the ball to keep it in

  correct in the valve body and to ensure

hermetic sealing.

  More specifically, the invention is particularly applicable to a valve of the type comprising a valve body with a central passage and a ball

  comprising a fluid flow opening

  in the central passage The ball is mounted to selectively rotate between the positions, valve closed and valve open to control the flow of fluid at

  through the valve Two shoulders extending radially

  inwards are arranged on circumferentially

  around the central passage on both sides of the ball, facing the ball The passage includes two

  chambers arranged on either side of the ball, each

  that chamber having an inner end wall facing one of the shoulders Two composite seat assemblies are disposed axially in the passage on either side of the ball to engage

  with it so as to be hermetic to the fluid.

  Each assembly comprises a reinforcing ring, a primary seat element comprising a ring

  flexible plastic, and a secondary seat element.

  The reinforcing ring has a central opening and is supported on one associated with the end walls of the recesses. The seat ring has a central opening and a ball engagement surface facing the ball to engage The secondary seat element comprises a deformable, heat-resistant secondary seat ring, preferably comprising an expanded carbon material, whereby in case of fire damage

  at the seat ring, the secondary seat ring engages

  pledge with the ball to close the valve.

  In another aspect of the present invention,

  the secondary seat element comprises a spring disc combined with a sheet of foamed carbon material.

  frustoconical configuration when not loaded.

  The sheet of foamed carbon material is generally axially stackable with the spring disk and is at least

  interposed between the spring and the seat ring

  mayor made of soft plastic The spring disc continuously pushes the sheet of carbon material and

  the soft seat ring towards the ball

  caused by fire to the primary seat ring, the sheet of carbon material comes into contact with the

  ball to ensure fluid sealing.

  According to yet another aspect of the invention, the

  secondary seat consists of two sheets of

  These two leaves surround the

  disc spring and are usually stackable axial-

  with it A first sheet faces the ball to engage with it when damage on the soft primary seat ring A second leaf faces the associated one of the two shoulders extending

  radially inward to engage hermetically

  with this shoulder during damage to the ring

primary seat.

  According to another aspect of the invention, a

  ring is included in the seat ring

  mayor and interposed in general between the seat ring

  primary and secondary seat element.

  In another aspect of the present invention,

  The ball has a second opening normal to the main opening of the ball fluid flow. The second opening faces the valve inlet when the ball is in the closed position, to communicate the fluid contained in the center. of

  the valve with the inlet fluid.

  The main object of the invention is to provide

  a ball valve and a new seat assembly.

  calf and improved and fireproof, which have

  improved shutter characteristics under the ef-

  fire or exposure of the valve to heat.

  Another object of the present invention is to provide such a ball valve and assembly seat, which avoids metal-on-metal fluid shutter engagements. Another object of the invention is to provide a ball valve which maintains fluid tightness upon complete or partial destruction by fire.

  a flexible primary seat element made of plastic.

  Another object of the invention is to provide a ball valve seat assembly, which avoids the insertion of primary seat ring or fire ash and debris threads between the ball.

  and the surfaces engaging with the ball to close the

tion.

  Another object is to provide a secondary seat

  which works in the event of fire damage

  the ball valve whatever the model and material

  primary building construction.

  Another object is to provide a secondary seat

  which does not deteriorate with age in

normally.

  Another object is to provide a fireproof ball valve which avoids the accumulation of high destructive pressures within the valve body and seat assemblies when the

  valve is exposed to high temperatures.

  Another object is to provide an assembly

  valve seat, which has a secondary seat

  which is removed from the deteriorating forces and

  wear due to fluid flow during normal operation.

  Other objects and advantages of the invention

  will appear to specialists when reading the specific

following cations.

  The invention can be concretised in certain

  Parts and arrangements of parts, among which a preferred embodiment and several others will be described in detail in this specification and illustrated.

in the following figures.

  FIG. 1 is a longitudinal sectional view of a

  ball valve which includes the preferential embodiment

the invention.

  FIG. 2 is an enlarged sectional view of a downstream seat assembly portion of FIG. 1 just prior to mounting of the valve and with the ball removed for

the ease of illustration.

  FIG. 3 is an enlarged sectional view of a seat of the downstream seat assembly of FIG. 1,

  but with the valve in the closed position under the

  fluence of the elevation of the fluid pressure of the system. FIG. 4 is a sectional view similar to FIG. 3 but with a valve having been exposed to fire if the flexible plastic ring has begun to

  flow through the valve orifice.

  Figure 5 is a sectional view similar to the figure

  4 o the ball has come into contact with the seat se-

ondary.

  FIG. 6 is a sectional view similar to FIGS.

  res 4 and 5 o the flexible plastic seat has been

completely destroyed.

  FIG. 7 is a plan view of the valve taken along lines 7-7 of FIG. 1, with a portion

  of the valve body removed to show a

improved bolting.

  Figure 8 is an enlarged sectional view of an assembly.

  seat cushion which comprises another embodiment of the invention. Figure 9 is an enlarged sectional view of another

embodiment of the invention.

  FIG. 10 is an enlarged sectional view of an assembly

  seat cushioning of a ball valve which incorporates

  core another embodiment of the invention.

  Figure 11 is an enlarged sectional view of another

  embodiment of a seat assembly comprising the invention

tion.

2534-658

  FIG. 12 is an enlarged sectional view of the assembly.

  siege of Figure 10, after partial destruction due to fire exposure and after

  removed from the valve body for illustration.

  Fig. 13 is an enlarged perspective view of

  the seat assembly of Figure 1 after destruc-

  partial exposure due to fire exposure and after

  have been removed from the valve body for illustra-

  tion. Referring now to the figures, where

  presented is in order to illustrate the reali-

  In the preferred embodiment of the invention and several others and not for the purpose of limiting the invention, FIG. 1 shows a ball valve A having two assemblies

  of seat B arranged on either side of a spherical ball

C floating type.

  More particularly, and with reference to FIGS. 1 and 7, the ball valve A comprises a body

  or housing designated by 10 having a central part

  12 and two opposite pieces of reinforcement 14, 16

  assembly seats B and ball C are mounted in the

  and the ball C * is arranged to be selectively rotated by a rod and an actuating assembly designated by the ball C comprises a first or main fluid flow opening; 5 extending over the diameter of the ball for communicating the fluid inlet and outlet flows when the valve is in the open position A second opening 17 normal to the main passage opening 15 is practiced in

  ball C and faces the inlet of the valve when

  that it is in a closed position to put in

  communicating the fluid and the fluid pressure at the center of the valve with the inlet fluid Practically, all the details of the parts of the valve shown

  in Figure 1, except for seat assemblies, may

  can be modified according to the wishes or the need

  to adapt to different types or styles of construction

valves.

  In general, however, and to describe the invention, the valve body includes a generally cylindrical, axially extending axial passageway or fluid passage, which is slightly larger in diameter than the C ball. end 14, 16 is connected to the central part of the body 12 so that it can be dismounted by several

  bolts designated together 22 extending longitudinally-

  passing through the bolt bores 24 of the opposite end plates 14 and 16 and attaching to the main body portion 12 (FIG. 7). It has been found that the use of several bolts 22 received

  in the main part 12 is particularly

  for a fireproof application to avoid the problems of elastic deformation or breakage of longer bolts that could happen

  after a valve has been heated to fire and

  cooled by water from a fire hydrant or sprinkler During a fire, metal parts

  of the valve will naturally expand under the

  fet of heat If a firefighter directs a spear on such a heated valve, the periphery of the valve, including the bolts, will cool and contract

  faster than the body of the valve Such a cool

  such a contraction may result in

  Also, when a plurality of shorter bolts are employed, such problems are minimized. The outer frames 14 and 16 also have

  internal threads 26 and 28 or any other suitable means

  requested to ensure the insertion of the valve into a

  fluid system or piping.

  The illustrated rod-handle assembly 18 comprises a rod 30 having a lower end 32 arranged as shown to be slidably received in a slot or groove 34 formed on the upper end of the ball C.

  This arrangement makes it possible to turn the ball of the posi-

  This valve opens at the closed valve position while allowing the ball a certain freedom of movement to move axially in the valve body passage 20 when the valve is in the closed position.

  and that the pressure of the fluid acts on the ball.

* The stem 30 extends outward through

  an opening 36 in the central part of the body 12.

  Lining rings 38, 40, 42 adapted to the temperatures

  high eratures are placed in aperture 36 and

  hermetically with the opening and the stem 30 Com-

  as can be seen, the lower lining ring 42 rests

  on a flange extending inward 44

  inside the opening 36.

  A thrust washer 46 adapted to the temperatures

  high tines is arranged under the flange 44 and

  against it by a shoulder or flange 48 extending outwardly formed at the base of the rod

  The rod is held in position by a press

  50 and a packing nut 52 As can be seen in FIG. 1, the tightening of the packing nut 52 applies a compressive force to the packing rings.

  trim 38, 40, 42 to make them expand radially-

  and form a tight seal around the stem.

  Although it is possible to operate the rod

  of the valve by many different types of action-

  This handle is attached to the rod 30 so that it can be disassembled by means of a handle 54.

  nut 56 which clamps the handle on the top of the nut 52.

  A coupling plane 58 may advantageously be formed on the outside of the rod to mate with a plane (not shown) in the opening of the handle to correctly position the handle on the rod. However, the position of the handle and, in turn,

  that of ball C are limited by the

  These stop pieces engage with appropriate surfaces on the central body portion 12 to provide stops.

  attached to the valve in the open and closed positions.

  Continuing to refer to FIG. 1, the ball seat arrangement used in the present invention comprises two seat ring assemblies B disposed on either side of the ball C. As can be seen, the ring assemblies of seat are kept tight in position on either side of the ends

  adjacent to the ball of passage 20 of the

  main body assembly The seat ring assemblies are arranged substantially at equal distances and on diametrically opposed faces with respect to

  the axis of rotation of the ball and include openings

  headings 66 and 68 Although the joint assemblies

  seat buckets can be held in position by many other or different arrangements, they have been represented as being held by the shoulders 70 and 72 defined by the end surfaces 74 and 76 of the reinforcements

  14 and 16, respectively.

  Inward movement of the seat ring assemblies is defined by two shoulders or steps 78 and

  which are defined by the inner surfaces of the

  two chambers extending inside the

valve body passage 20.

  In addition, a seal is disposed between the central part of the body 12 and the end plates 14 and

  16, in the form of rings 82 and 84 arranged in segments

  * Chambers 86 and 88, respectively, Each annular seal is disposed on the outer circumference or the outer peripheral surface of a portion of the associated seat ring assembly B

  rings are preferably made of deformed material

  mable, resilient, heat resistant and thermal-

  stable as an expanded and reinforced carbon composite material, to avoid the problems of sublimation and

  of combustion which may occur, for example during

  that a thermoplastic ring gasket of conventional

  is exposed to fire or other temperatures

  In the preferred embodiment, it has been

  gravely used Grafoil (a trademark of Union Carbide Corporation) as a material

  deformable heat resistant However, we remark

  that other materials can also be used.

  like asbestos or composite ceramics.

  When the main portion of the valve body 12 and the opposite end fittings 14 and 16 expand and contract under the effect of reheating and cooling during and after a fire, the annular seals 82 and 84 continue to provide a seal satisfactory between the main body part and

the end frames.

  The structural details of ball A described

  above refer to the preferred valve embodiment

  It is clear to the specialists,

  however, that modifications may be

  to meet operational requirements or requirements Such changes will not affect

  not the general intention or the scope of this

  tion as it will be described in detail below.

  below. Referring to Figures 2 to 6 and 13, the

  seat assemblies B comprising the preferred embodiment

  BRIEF DESCRIPTION OF THE DRAWINGS FIG. 2 shows a sectional view of the downstream seat assembly disposed against the end armature 14 prior to mounting of the valve. The ball C has been erased to facilitate the understanding and appreciation of the constitution of the seat assembly FIG. 3 shows a view of the seat assembly of FIG. 2 after the mounting of the valve, the latter being in closed position and under

  the influence of the high fluid pressure of the system.

  Figures 4, 5 and 6 illustrate the seat assembly B at successive stages after the valve has been exposed to fire. FIG.

  flexible plastic primary seat that began to

  The figure shows the valve after the ball has come into contact with the secondary seat Figure 6 shows the valve after the flexible plastic primary seat ring has been completely destroyed and spun or evaporated outside the valve body Figure 13

  shows the seat assembly B after partial destruction

  the like when the valve is exposed to a fire or

  radiant heat on one side lines 3-3, -

  4-4, 5-5 and 6-6 of Fig. 13 correspond to sectional views of the seat assembly B shown in Figs.

  Figures 3, 4, 5 and 6 respectively.

  Referring particularly to the figures

  2 and 3, the seat assemblies B preferably comprise

  three components, namely a reinforcing ring

  100, a primary seat member 102 comprising a flexible plastic ring, and a secondary seat member 104 comprising a heat-deformable and non-heat-fusible seat ring Although only a portion of one of the assemblies seat

  shown in these figures, it should be noted that the other assembly

  Seat cushioning is identical to this one, unless specifically specified.

  annular configuration comprising a central opening

  tral; it is made of a rigid material such as steel or other suitable metal A first circumferential continuous surface or terminal face 106 of

  the ring faces the associated shoulder 70 of the armament

  A second continuous surface 108 faces and abuts against the end surface or steps 78 of the recess of the passage 20 of the main body part to establish an extreme position.

  forward for the reinforcement ring A third

  the continuous surface 110 generally faces the ball, but is dimensioned so as to be spaced therefrom to avoid any abutment or interference therewith and to prevent any distortion or displacement

  of the associated primary seat ring 102 between the third

  sth surface of the reinforcement ring 110 and the

  ball The outer circumference or peripheral area

  The outer surface 112 and the second surface 108 may comprise a flange or step disposed and dimensioned to engage with the shoulder 78, the ring support 100 can extend further into the interior of the passage 20

  if the general dimensions of the valve require it.

  However, such an additional collar is not

  included in the realization to avoid

additional machining.

  Continuing to refer to FIGS. 2 and 3, it will be noted that the primary seat element 102 comprises

  also an annular or ring-shaped element

  having a central opening 118 smaller than the

  central opening of the reinforcement ring 100.

  The primary seat element preferably comprises a flexible plastic seat ring and is arranged for

  able to flex towards the reinforcement ring 100.

  The seat ring 102 is arranged to exert a resistance

  elastic mechanical spring like that of a spring on the ball A first surface 120 faces globally

  at the associated shoulder 70 of the end armature 14.

  A second seat ring surface 122 faces the reinforcing ring 120 to abut with and be supported by the first surface of the ring A third surface of the seat ring or surface engagement with the ball 124 globally faces ball C to engage tightly

  with it A flange or lip 126 extends axially

  outwardly of the first seat ring surface 120 from the outer peripheral surface

  Lip 126 is preferably continuous with the

  seat ring and positioned so that its inner radial surface corresponds to the outer diameter of the secondary seat member 104 The flange or lip 126 is further beveled to its outermost radial surface and wraps slightly around the

  outer radial edges of the secondary seat element

  figuratively, although it is not

  indispensable, this provision maintains an advantageous

  together the primary and secondary seat elements

  As a subset Preferably, the seat ring 102 is made of a flexible plastic material

  and resilient like Teflon, polyethylene or similar

  It should be noted, however, that a wide variety of other types of materials such as acetal resin or the like or even flexible metal composites

  and ceramics could also be used profitably.

  The particular material chosen will depend, in a

  some extent, normal operating conditions

to which the valve is subjected.

  Inside the primary seat ring 102 is a stop ring 130. Preferably, this ring is placed in a groove or concavity 132 of the seat ring 102, which is isolated from the fluid passage of the valve. it would remain within the scope of the invention that the stop ring 134 be entirely enclosed in the seat ring 102 or, in another way, entirely outside the seat ring as, for example, an axially directed lip of the secondary seat member 104 extending toward the ball at the inside diameter of the primary seat ring 102.

  preferably, however, the stop ring 130 is globally

  arranged at an intermediate radial position of

  the seat ring 102 between the second seat element

  associated with 104 and C ball In this location

  preferential, the stop ring 130 is isolated from the expo-

  the same wear and damage hazards that affect the flexible primary seat element 102 in normal service The stop ring is made of a material

  thermally stable, non heat fusible, of pre-

  a composite of Grafoil and a metal mesh

  similar to the material of the annular seals 82 and 84; however, in addition to the Grafoil itself, a metal mesh, a ceramic or even metal

can be used.

  The secondary seat member 104 comprises a subassembly having a frustoconical disc-shaped central spring 134 sandwiched between a first annular sheet 136 facing the associated shoulder 70 and

  a second annular sheet 138 facing the element

  102 and 136 are preferably made of Grafoil and are generally

  axially stackable with the spring disc 134; How-

  However, it would remain within the scope of the invention that the sheets 136 and 138 extend only over a portion of the spring disk as in the case where, for example, the first sheet 136 would extend only over a portion of the spring disk. 134 near the outer diameter of the spring disc, and the second sheet 138 would extend over a portion close to the inside diameter of the disc

  This last embodiment can be particularly

  particularly economical and advantageous in the case of

large ballpoint popes.

  It has been found advantageous for the surface 74 of the supporting shoulder 70 to be knurled or grooved for proper engagement of the spring disk sheet 136. Upon exposure of the valve to a fire, such engagement improves the slip, the

  casting or spinning of the sheet and disc spring.

  The Grafoil can at high temperatures become somewhat fuse The knurled or grooved surface avoids a

  such action and facilitates sealing of the seal.

  The diameter at the outer end of the element

  The secondary seat 104 is such that the element can be accommodated in the cylindrical cavity defined by the inner wall of the axial flange 126 of the seat ring and the first seat ring surface 120. secondary seat element is slightly larger than the diameter of the aperture 118 of the seat ring 102 to substantially isolate the secondary seat element of the contact in use

  normal with the ball and the risks of wear and tear

magement associated.

  The spring disc 134 is chosen so that its stiffness is sufficient under partial bending to continuously push the seat ring 102 towards the ball. The spring must also be able to bend to a flat position to allow the movement of the seat.

  ball and its commitment to the third surface of

  seat ring 124 in normal operation.

  With particular reference to Figure 3, it is

  tate that a tight seal is achieved by keeping tight

  the primary seat ring 102 between the ball C, the annulus

  In the normal operating situation, the secondary seat member 104 acts first to push and hold the primary seat ring 102 without the support surface 100, the valve main body 12, and the outer frame shoulder 70. perform secondary shutter action. Referring to Figures 1, 2 and 3, and to

  moment of assembly of the valve, each of the

  Seat wicks B moves so that each of the primary seat rings 102 flexes slightly at its outer periphery and against the seat member

  104, in response to the commitment between

  ball engagement face 124 of seat ring and ball C This action slightly compresses the disc

  spring 134 to a flattened position In addition to the

  the positioning of the ball, this bending of the spring ensures a closing force between the two

  seat rings and the ball, on the engagement surface

  ball 124, regardless of the fluid pressure

  in the system The vent hole or secondary opening

  17 in the ball C faces the inlet when the valve is closed and ensures that the inlet seat does not close Any fluid in the center of the valve is free to expand under the effect of heat or vaporization, and escapes through the vent hole

  17 without increasing the pressure in the valve.

  With particular reference to FIGS. 4, 5, 6, 12 and 13, the operation of the embodiment

  preferential described below will be described specifically.

  only if the primary seat is destroyed by fire.

  Figure 4 shows the plastic seat ring

  flexible tick 102 heated to a more fluid state, and flowing or threading through the central opening 66 of the secondary seat member 104 under the effect of fluid pressure forces in the valve.

  softening of the seat ring 102, the disc

  fate 134 of the secondary seat member 104 flexes to maintain a seal against the ball C and the side 74 of the shoulder 70. Referring particularly to Figure 5, the ball has moved downstream in the valve A to compress the secondary seat member 104 and abut against the stop ring 130 The second sheet 138 which is caught between the spring disc 134 and the ring

  seat 102 comes into contact with the ball C in its

  radially the innermost part to ensure an ob-

  sealed ration The second sheet 138 is preferably made of a heat-resistant deformable material such as Grafoil, the sheet will conform to the engagement surface of the ball C, thus avoiding the problems of previous models of ball valves which included metal-on-metal secondary seals. Similarly, the first

  sheet 136 of the secondary seat element 104 is

  pledge with the support shoulder 70 to the end wall 74 of the shoulder in its radially outward portion, to ensure sealing tightness The property of

  deformability of the sheet 136 allows it to conform

  form to the irregularities of the surface 74 and the edge

  outer radial spring disk 134.

  It would remain within the scope of the invention of

  clure a secondary seat element 104 without first or second leaf 136 and 138 because it has been found that

  the disk spring 134, due to its elasticity cir-

  conférentielle; would be a metal-on-metal joint

  acceptable with ball C, thus solving the problems

  problems resulting from the non-sphericity of the ball, and from the fact that it is not lapped with the seat element

secondary.

  The spring disk 134 of the secondary seat element has a circumferential elasticity

  as well as axial elasticity and during softening

  When the seat ring 102 is depressed, the secondary seat element bends to maintain a seal between the ball C and the end face 76 of the shoulder 70. By circumferential elasticity is meant the capacity of the seat element. secondary seat to bend axially in a segment more than in

another segment.

  The ball C is not perfectly spherical and the central opening 66 of the disk spring 134 being

  not perfectly round, the ball and the spring

  will only be in contact on a few points.

  circumference of the spring 134 allows him to

  bend in varying degrees along one's peri-

  meter on these points and therefore to establish a substantially continuous contact line between the

  inner radial edge of the spring disk 134 and the ball.

  Similarly, the outer -radial edge of the disk

  Fate 134 touches the end face 74 at only a few points. The circumferential elasticity of the spring disc 134 again allows it to flex in

  varying degrees along its perimeter and consequently

  to establish a substantially continuous contact line between the outer radial edge of the disk

  spring 134 and the end face 74 of the shoulder 70.

  Thus, the circumferential elasticity of the disc

  Fate 134 compensates for imperfections in the roundness of the inner and outer edges of the spring disk 134, the imperfections in the sphericity of the ball C, and imperfections in the plane of the surface

74 of the shoulder 70.

  The stop ring 130 acts as a "dam" to prevent excessive spinning of the plastic seat 102 softening between the ball C and the secondary seat member 104 toward the valve orifice. In practice, a fire can do not always heat evenly

  surface of a fire-proof valve, particularly

  if that fire is a fire-fire near the

  pope and that he heats the near side of the valve, but not the opposite side So, during a fire, one

  can reasonably foresee that the plastic seat ring

  tick 102 may soften in a first part

  only from its circular perimeter before softening

  In other areas Without the stop ring 130, the first part could spin excessively towards

  the valve port under the pressure of the system,

  ball C move radially or sideways

  As a result, since ball C would move downstream through the softened plastic to meet the secondary seat element 104, the ball could move too far to one side and retract. in uneven contact with the secondary seat element 104, leaving gaps

  and leakage passages through which the plastic-

  Melting and system fluid could escape.

  It has been found that such voids and leaks generally occur at ninety degrees of the radial displacement vector. The point at one hundred and four twenty degrees of the radial displacement vector retains its seal by contact with the rest of the radial displacement vector. plastic primary seat 102 The irruption of the fluid of the system can then cool the plastic seat 102 and prevent further melting A large leak thus developed can remain a big leak whatever the fire subsequently applied to the valve to

fireproof.

  Another mechanism for partially destroying the seat is shown in FIG. 12. A seat assembly that does not include a stop ring is shown after exposure to fire which has caused it to pass to the valve port only a portion 141. A large leak 143 resulted from the ball's inability to touch

  the secondary seat element 104 The ball C is

  against any radial or axial movement towards the por-

  spun by the remaining portion of the primary plastic seat ring 102 The sudden cooling action of the leak protects the plastic seat ring

  primary protection against further destruction or spinning.

  despite variations in the intensity of the fire.

  However, referring to Figure 5, the

  Stopper 130 retains the flow of molten soft plastic regardless of the location of the perimeter of the seat where softening occurs first. The stop ring 130 is positioned on the seat ring 102 so that only a narrow annular portion

  can flow to the valve port The main part

  The relatively small portion 144 which can spin on comprises a small amount of substance and during its spinning, the displacement surface in which the ball C can then be prevented from spinning by the stop ring 130. It is also preferable for the stop ring 130 to be placed in the seat ring 102 so that the ball C touches the stop ring 130. same time as the secondary seat element 104 the stop ring 130, thus,

  can further contribute to securing secondary closure

  in the event of destruction of the primary seat

Mayor 102.

  Referring to FIG. 6, the primary seat member 102 has been completely destroyed, so that the main portion 146 (FIG. 5) of the flexible plastic seat ring has sublimated or evaporated toward the orifice A seal remains between the ball C and the secondary seat member 104,

  the ball remaining in contact with the radial part

  the first sheet 138 which deforms in accordance with the surface of the ball The first sheet 136 engages similarly with the end wall 74 to

  maintain the seal between the secondary seat element

  In addition, it is advantageous for the stop ring 130 to be of a size such that it

  engaged with the ball during the destruction of the

  primary siege and the associated displacement to

  downstream of the ball Such an engagement facilitates the ob-

hermetic ration.

  Looking closely at Figure 15, along lines 6-6, it can be seen that the ball has

  hit the stop ring 130 after destruction of the

  primary seat and also touched the secondary seat element to seal (Figure 6) Along the lines 5-5, the spinning of the main part of the primary seat element is stopped by the ring 130 to prevent the formation of

the leak of Figure 12.

  With particular reference to Figure 8, another embodiment of the present invention is

  For ease of illustration and ap-

  In this alternative embodiment, the identical components are identified by identical numbers with a suffix "prime" (') and the new components are identified by new numbers. The secondary seat element 104' comprises a single disk element of a heat-resistant deformable material such as Grafoil or a compound of Grafoi'il and a metal mesh When fire damage on the primary seat element 102 ', the ball C' can move axially downstream under pressure of the fluid to engage with the inner radial portion of the secondary seat member 104 'to seal tightly Moreover, the wall 74' which is preferably knurled engages with the end face 152 of the secondary seat element to provide a seal between the secondary seat member and the support shoulder 70 'The secondary seat element 104' can thus comply with the -surfaces eng agement

ball C 'and wall 74'.

Another embodiment of the invention is illustrated in FIG. 9, where like components are identified by identical numbers with a suffix.

  "second" (") Secondary seat element 104"

  takes a spring disc 134 "and a sheet 156 of a deformable and heat-resistant material such as Grafoil or a Grafoil composite and a metal mesh When destroying the primary seat element 102" in a fire , the ball in position

  closed in advance under the pressure of the system against

  104 "and covers the sheet 156 in its radial inner portion to ensure a seal sealing Moreover, when the fire progresses, the disk spring 134" anneals The spring disc softening, pressed by the ball under pressure , conforms better to the surface 74 "of the supporting shoulder" and achieves a better metal-metal seal behind the spring Yet another achievement of

  the invention, similar to this embodiment, comprises

  should have a single sheet on the surface of the disc spring,

  facing the supporting shoulder Such a construction

  would involve a secondary metal-to-metal

  with the ball and a seal with leaf with the

  wearing It is best to use a knurled shoulder

to touch the leaf.

  Figure 10 shows another embodiment of the present invention, o identical components

  are identified by identical numbers with a suffi-

  This embodiment of the invention comprises a seat assembly comprising a support ring 100 "', a primary seat element or seat ring 102"', a first sheet 136 "'and a second sheet 138 "'Leaves 136"' and 138 "'are made of a deformable material and resistant to

  heat like the Grafoil There is no stop ring.

  During the destruction of the seat ring 102 "'in a fire, the ball moves axially downstream and

  provides a seal with the second sheet 138 "'.

  The first sheet 136 "engages with the knurled outer surface 74" 'of the support shoulder 70 "' to maintain

gasket.

  Finally, FIG. 1 relates to yet another embodiment of the present invention in which identical components are again identified.

  numbered by identical numbers with a suffix

  "secondary" ("") The secondary seat element 104 "" may

  take a simple spring disk, a non-fuse deformable disk made of a material such as Grafoil or a Grafoil composite and a metal mesh, or a combination of a spring disk and a Grafoil sheet similar to the secondary seat element 104 "

  illustrated in FIG. 9 A stop ring 130 "", constituting

  truit preferably in a Grafoil compound and a metal mesh, is included in the primary seat element 102 "" to come into contact with the ball during a partial or total destruction of the element

  primary seat, and to stop the spinning of the door

  main bearing 146 "" of seat ring 102 "".

  Other modifications not specifically shown in the figures may be made to the

  assemblies of seat rings B without departing from the in-

  For example, one may wish to

  slightly differentiate the relative dimensional characteristics between the primary seat elements, the

  reinforcement rings and the secondary seat elements

  to meet operational requirements

special.

  The invention has been described with reference to

  a preferred embodiment and several others.

  Of course, changes and changes may lead to further achievements in reading and understanding this specification.

  is to include all modifications and changes

  such as they fall within

  the scope of the attached claims or their equivalent

slow.

Claims (33)

  A fireproof ball valve, comprising:   a body (10) having a central passage   tral (20); a ball (C) comprising through it a fluid circulation opening (15), said ball (C) being positioned in said passage (20)   and mounted so that it can rotate between   Open and closed valve arrangements for controlling the flow of fluid through the valve;   two shoulders (70) extending radially   inwardly in said passage (20) disposed on the circumference thereof on either side of said ball (C); and two recesses extending radially inward in said passage disposed on either side of said ball, each of said recesses having an inner end wall; characterized in that it comprises two assemblies   seat (B) composites arranged on the axis of said step   wise (20) on either side of said ball (C) for fluidtight engagement with said ball (C), each of said seat assemblies (B) comprising a reinforcing ring (100) having a central opening and abutting on an associated said inner end walls chamberings; a seat ring (102) abutting said reinforcing ring (100) and adapted to flex elastically in the general direction of said reinforcing ring (100) and in the opposite direction, said seat ring (102) including a central opening ( 118) and a ball engagement surface (C) facing said ball (C) for sealing engagement with said ball (C); and   a secondary seat element (104) comprises   a spring disc (134) having a central opening (66) in generally frusto-conical configuration when not loaded, interposed between said ring   of said seat and said partner of said shoulders and   at least one annular sheet (136) of a material   carbonaceous foam disposed on one side of said   1 o spell (134); said ball (C) and said two composite seat member assemblies (B) being dimensioned so that upon damage to said seat   seat ring (102) by exposing said   populated at high temperatures, said secondary seat member is pushed to a hermetic engagement with said ball (C).   Valve according to claim 1, characterized   characterized in that said ball (C) and said two seat assemblies (B) are sized so that when assembled, said seat ring (102) and said secondary seat member (104) of each seat assembly (B) ) are bent and constrained to push said seat ring (102) toward contact with said ball (C).   Valve according to claim 2, characterized   characterized in that said "at least one sheet" comprises   first and second sheets (136, 138)   on opposite sides of said spring (134) and are   axially stackable with it.   Valve according to claim 3, characterized   characterized in that said first sheet (136) of   carbon fiber is placed contiguously to an associated one of said two shoulders (70) and said second sheet (138) is placed contiguously to said ring of seat (102).   Valve according to claim 4, characterized in that upon damage to a ring of   seat (102) due to exposure to high temperatures   said second sheet 138 contacts said ball (C) to provide a fluid tight seal with her.   Valve according to claim 5, characterized   characterized in that said sheet (138) is in contact with said associated shoulder (70) to provide a seal fluid tight with it.   Valve according to claim 1, characterized   characterized in that said two radially inwardly extending shoulders (70) have knurled surfaces for engagement with said seat member secondary (104).   Valve according to claim 1, characterized   in that said two shoulders (70) extending radially inwardly are fixed to said body by a plurality of fasteners received in said body.   Valve according to claim 1, characterized   in that said ball (C) further comprises means for preventing increases in pressure in said valve body (10) due to heating and vaporization of the fluid upon exposure of said   valve at high temperatures.   Valve according to claim 9,   in that said means avoiding the   Pressure arrangements comprise a vent port (17) normally disposed at said fluid inlet opening of said valve upon closure of said valve.   Valve according to claim 1, comprising   further including a stop ring (130) in at least one of the composite seat assemblies to prevent spinning of said seat ring (102) during the exposure   of said valve at elevated temperatures.   Valve according to claim 11, characterized   characterized in that said stop ring (130) is dis-   placed in one of said seat assemblies (B),   substantially isolated from said central aperture of the associated seat ring (102) to prevent exposure of said stop ring (130) to wear hazards.   normal operation of the valve.   Valve according to claim 12, characterized   characterized in that said stop ring (130) is enclosed in said seat ring (102).   Valve according to claim 1, characterized   characterized in that said annular foil of foamed carbon material (138) is disposed in at least one of the seat assemblies (B) in substantial insulation   of said central opening of the associated seat ring   cié to avoid the exposure of said sheet to the hazards   wear of the normal operation of the valve.   Valve according to claim 14, characterized   characterized in that said annular sheet of carbonaceous material exparated by Osé (138) is interposed between said ring   seat (102) and said spring disc (134).   Valve according to claim 14, characterized   characterized in that said annular foil of foamed carbon material (138) is interposed between said spring disk (134) and an associated one of said two shoulders   (70) extending radially inwardly.   17 Ball valve comprising a body comprising   both a central passage (20), a ball (C) having a fluid passage opening (15) therethrough and being disposed in said passage (20) and mounted to be selectively rotatable between the open and closed valve positions for controlling the flow of fluid through said valve, and two shoulders (70)   extending radially inwardly in said step   wise (20) disposed on a circumference thereof on either side of the ball (C), characterized in that it comprises: 2534658 '   a seat member having an elastic seat ring (102)   disposed in said passage (20) to engage   fluidly with said ball (C) and a deformable, heat resistant, secondary seat ring (104) interposed between said resilient seat ring   (102) and an associated one of said two shoulders (70), -   said secondary seat ring (104) being substantially   partially isolated in normal operation from contact with the ball (C) and the fluid of the system, whereby during damage caused to said elastic seat ring by exposure to high temperatures, said secondary seat ring (104) s engage with said   ball (C) for sealing said valve.   Valve according to claim 17, characterized   characterized in that said secondary seat ring (104)   is made of an expanded carbon material.   Valve according to claim 17, characterized   characterized in that said seat member further comprises a spring disc (134) interposed between said   secondary seat ring (104) and that associated with-   say two shoulders (70) to push said elastic ring   tick (102) and said secondary seat ring (104) in engagement with said ball (C)   Valve according to claim 19, characterized   characterized in that said disk spring (134) and said   secondary seat ring (104) are generally super   posables axially with each other.   Valve according to claim 17, characterized in that   characterized in that said shoulders (70) are fixed to said body (10) by a plurality of fasteners (22) received in said body.   Valve according to claim 17, characterized in that   characterized in that one of said two shoulders (70) has knurled surfaces for engagement with said secondary seat ring (104).   23 Ball valve of the type comprising a   valve body (10) having a circulation passage   pouring the substantially cylindrical fluid (20), a ball (C) disposed in said passage (20) mounted to be selectively rotatable between the open and closed valve positions, said ball (C) being movable in a generally axial direction in   said passage at least when the valve is in position   closed under the influence of fluid pressure, two annular seat rings disposed in said passage (20) on either side of said ball (C) between said ball (C) and two shoulders (70) of the body valve assembly, characterized in that it comprises: a stop ring (130) associated with at least one of said two seat rings to prevent spinning of said seat ring during the exposure of   said valve at elevated temperatures.   Valve according to claim 23, characterized in that   characterized in that said stop ring (130) is disposed at a radially intermediate position of said ring seat.   Valve according to claim 24,   characterized in that said stop ring (130) is received in an annular groove in said seat ring (102).   Valve according to claim 25, characterized   characterized in that said annular groove is disposed in said seat ring (102) in isolation from said fluid flow passage (118) to prevent exposure of said stop ring (130) to wear hazards   in normal operation of the valve.   Valve according to claim 25, characterized   characterized in that said stop ring (130) is enclosed in said seat ring (102).   28 Valves according to claim 23, characterized   characterized in that said valve further comprises two annular spring disks interposed between each seat ring (102) and the associated shoulder (70) for continuously urging said seat rings (102) into contiguous engagement with the ball (C), and in that the annular spring disk (130) associated with at least one of the seat rings (102) comprises an annular surface sheet made of a material resistant to heat.   Valve according to claim 28, characterized in that   characterized in that said stop ring (130) is globally   interposed between said seat ring (102) and   the associated one of said spring disks.   Valve according to claim 28, characterized in that   characterized in that said heat-resistant material   comprises an expanded carbon material -   Valve according to claim 28, characterized   characterized in that said surface sheet is   placed on each opposite side of the spring disc   (130) and generally has the same radial extent is lying.   Valve according to claim 28, characterized   characterized in that said annealed surface sheet   the sheet is disposed on each of the opposite faces of said spring disk (130), and comprises a first surface sheet (136) extending over a portion of a first face of said disk spring near an outer diameter of said spring facing said associated shoulder (70), and a superficial second-sheet (138) extending over a portion of a second face of said disk spring near an inside diameter of said   spring facing said ball.   Valve according to claim 23, characterized in that   characterized in that said stop ring (130) comprises an axially directed lip of one of said two annular spring discs, extending towards said ball to the inside diameter of the associated one of said two annular seat rings.   Valve according to claim 23, characterized in that   characterized in that said stop ring (130) is dimensioned to contact said ball (C)   when destroying the associated seat ring.   Valve according to claim 34, characterized   characterized in that said stop ring (130) is further sized to contact an associated one of said two valve body shoulders (70) upon destruction of said associated seat ring (102) by temperatures. raised to form a fluid-tight seal between said ball and said associated shoulder.   36 Ball valve comprising a body (10) having a central passage (20), a ball (C) comprising through it a passage opening (15) of the fluid positioned in said passage (20) and mounted to selectively rotate the valve position open to the closed position to control the flow of fluid through said valve,   and two shoulders (70) extending radially towards the   interior of said passage (20), arranged on a circumference   of the latter on either side of the ball (C), characterized in that it comprises: a primary seat element comprising a   flexible seat ring (102) supported in said step   wise (20) for sealingly engaging the fluid with said ball (C), and a secondary seat member   (104) deformable heat resistant recessed in the   interior of said primary seat member to isolate said secondary seat member (104) from the normal operating contact with the ball (C) and the fluid of the system, whereby upon damage to said flexible seat ring (102) by exposure to high temperatures, said secondary seat element   (104) engages with said ball (C) to seal the said valve.   Valve according to claim 36, characterized   characterized in that said secondary seat element   (104) is disposed at a radially intermediate position   of said primary seat element and is   to prevent spinning of said seat ring   flexible through said central passage during the ex-   position of said valve at elevated temperatures.