DE2942341A1 - Fire safe butterfly valve - has resilient high-temp. destructible seal and seat ring pre-loaded against valve - Google Patents

Abstract

The butterfly valve comprises a seal for a movable valve member in the form of a resilient high temp. destructible sealing ring and a resilient high temp. indestructible seating ring. Both are normally preloaded into radial sealing engagement with the movable valve member. The high temp. destructible seating ring is the primary seal and the high temp. indestructible seating ring is a backup seal in one direction of flow. The high temp. indestructible seating ring is the primary seal in the opposite direction flow. Upon destruction of the high temp. destructible seating ring, the high temp. indestructible seating ring is so retained and configured to provide bidirectional seating.

Description

Fire-safe butterfly valve

The present invention relates to throttle valves. In particular, it relates to butterfly valves with seat rings that are destructible and indestructible at high temperatures and specifically a throttle valve in which the indestructible Sitzrinq usually against the movable Valve element is preloaded and in the preload division of a holding arrangement in the surrounding the flow channel Inner wall surface of the valve body held will.

Valves that · in flammable substances such as hydrocarbons Leading lines are to be inserted, must seal tightly at normal temperatures as well as other temperatures, the sealing elements made of destructible at high temperatures Would destroy materials. State-of-the-art fire-safe valves contain indestructible seat elements, which take effect when the destructible seat element has been destroyed, or which only work in one direction. As the TempuiaLuren in which the seating element is destroyed but can occur on both sides of the movable valve element, an indestructible seat element is required, that can shut off the line in both directions.

Other considerations are low construction costs, a easy assembly of the valve assembly as well as the freedom

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of adjustment work after assembly.

According to the present invention is a seat assembly having a resilient destructible seat ring as well as an indestructible one Metal seat ring arranged so that normally at normal temperatures there is a redundant bidirectional closure, with the metal seat ring providing a bidirectional closure, if the destructible elastic seat ring is destroyed by fire.

The metal seat ring is in the valve body adjacent to the arranged elastic seat element and protrudes radially inward into the flow channel. The furthest radial inner end of the metal seat ring is folded back about 180 ° on itself, so that a substantially Flat seat part is created, which runs according to the sealing surface of a valve element, and the outer edge is standing engages with a structured part of the inner wall of the valve body surrounding the flow channel and is supported by it. The dimensions of this structured inner wall part are chosen so that the curved seat part exerts a predetermined preload on the valve element and the seat ring to move in the axial direction is prevented under the fluid pressure, so that a tight seal is created in both directions of flow. Furthermore, the metal seat ring is provided with openings on its seat part, so that the fluid pressure the sealing effect is reinforced in one direction. A valve according to the present invention allows a tight seal in both directions of flow within permissible leakage losses at pressures from 0 to 5.1 MPa (0 to 740 psi) at normal temperatures as well as temperatures at which the redundant, destructible elastic sealing element is destroyed.

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An aim of the present invention is to provide a cheap to manufacture, Specify throttle valve that is easy to assemble and fireproof at high temperatures.

It is another object of the present invention to provide a bidirectional fireproof butterfly valve.

Another object of the present invention is to provide a fireproof metal seat ring and bracket for indicate this in such a way that a selected preload is applied and a holding force against the flow pressure can be generated in both directions.

The invention will now be based on an exemplary embodiment Referring to the accompanying drawings are explained in detail, wherein the same or corresponding parts are identified by the same reference numerals in the various figures.

Fig. 1 is a vertical section on the central plane of a throttle valve according to the present invention ;

Figure 2 is a detail taken in vertical section on the plane 2-2 of Figure 1;

Fig. 3 is a representation corresponding to Fig. 2 and shows the arrangement after that at high temperatures destructible sealing element has been destroyed; and

Figure 4 is a partial perspective view of the flexible Metal sealing ring.

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Fig. 1 shows a throttle valve arrangement with a valve body 11 with a central flow channel 12, the is designed so that it can accommodate a valve element in the form of a disk 13, which is designed as a spherical layer is. As shown in FIG. 1, the larger or right-hand side of the disk is on a valve control stem 14 attached, which is rotatably mounted in the valve body 11 and whose axis of rotation runs centrally with the axis of the ball from which the disk 13 represents a layer. The valve arrangement can, for example, with the bolts 15 passing through the body 11 and through flanges 16 of the pipe connections 17, 18 extend on both sides of the valve into a fluid line insert.

As best shown in FIGS. 2 and 3, the valve body 11 includes a generally designated by the reference numeral 2 1 circumferential cutout in the left side of the valve body 11, from the flow channel 12 radially outward runs. In the circumferential cutout 21, for example with the bolts 22, there is a retaining ring 23 for the seat element set, the inner surface of which surrounds the fluid channel 12 of the valve body to the left of the valve disc 13. The retaining ring 23 contains a cutout which is inclined to the right and which is generally identified by the reference number 24 and its radially outermost inner wall surface 25 and its generally axially facing inner wall surface 26 ingeniously with the axially opposite wall surface 27 of the cutout 21 in the valve body 11 a Form the seat element receiving recess 28, which can best be seen in FIG. 3. The helix angle of the Recess 28 is created in such a way that an elastic seat ring, generally designated by the reference numeral 31, in it is, is brought into the desired position generally at right angles to the sealing surface 32 of the movable disc 13. The interior

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surfaces 26, 27 of the recess also form a wedge around the base or the radially outermost one To receive part of the elastic seat ring 31 with a tight seal, the axial dimensions of which are sufficiently larger than the wedge dimensions to provide an effective seal. The radial dimension of the seat ring 31 is such that it has its radially most inner part 30 tightly on the surface 32 of the valve disc 13 rests.

The elastic seat ring 31, which can be destroyed by high temperatures and preferably consists of polytetrafluoroethylene, is formed with radially spaced and axially directed grooves 33, 34, of which the radially inner groove 33 serves to increase the radially directed sealing pressure through the effect of the flow pressure from the left, as with indicated by arrows 35 in FIG.

According to the present invention, a flat seat ring made of metal, which is shown in a partial representation in FIG is formed with a radially outermost ring part 37, which is between the retaining ring 23 and the axially facing end wall 27 of the cutout held in a sandwich-like manner in the valve body radially outward of the recess is, as shown in the figures to the right of the elastic sealing ring 31, both sides of the ring part are for the purpose of one fire-safe conclusion graphite rings 38 arranged, as they are under the name GRAFOIL in the trade. The seat ring 36 stands in the recess 28 along the axially facing surface 27 of the cutout 21 in the left side of the valve body 11 before; it also protrudes into the flow channel 12, where the radially most inner one Part is bent to the right and then by essentially 180 ° back on itself, so that a seat 41 is formed

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which runs corresponding to the sealing surface 32 of the valve disk 13. The radially outwardly directed terminating edge 42 of the ring slides along a slope 43 when assembling the valve and then engages on an opposite one directed slope 44 in the wall of the flow channel 12 at the opening of the recess 28. The design or dimensions the edge 42 and the incline 4 4 determine the preload that the seat surface 41 of the ring 36 on the sealing surface 32 of the valve disc 13 applies. The oppositely directed slopes 43, 44 serve together with the Edge 42 also contributes to the deformation of the seat surface under the flow pressure from both sides by defining the edge 4 2 to keep the valve disc 13 to a minimum. The bevels 43, 44 thus form a crown ("formation").

Fig. 3 shows the throttle valve after the elastic seat ring 31 has been destroyed by fire. Under the flow pressure from the left, the end face 27 of the valve body supports the flexible metal seat ring 36, while because the edge 42 of the ring 36 rests on the bevel 44 in the duct wall, the seat surface 41 does not extend that far can deform that the tight seal is lost.

If the flow pressure acts from the right, prevents the edge 42 of the ring 36 from resting on the slope 4 4 in the wall of the channel 12 also causes a deformation of the seat surface 41. As shown in FIGS. 2 and 3 and in particular in FIG. the edge 42 can be provided with notches 45 at angular intervals of, for example, 4 5 °, so that the flow pressure act from the right between the wall of the flow channel and the curved part and thus increase the sealing pressure can.

For high temperature applications where the normally

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occurring temperatures are higher than the destruction temperature of the elastic seat ring 31, only the seat ring 36 is used.

The seat ring 36 can be made of stainless steel or another high temperature resistant metal material such as Inconel, titanium, beryllium or the like exist. Furthermore, the sealing surface 32 of the disc 13 and also coat the seat surface 4 1 of the seat ring 36 with metal in order to improve its hardness and wear resistance.

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Claims (3)

1 BERLIN 33 8MUNCHEN80 Augu.U-Vilclonn-Straftii 66 η ηιιοΛίιι / Γ ο nmTiirn PienianauaialiaB ΡΛ-Α «.. D ,. Ing. R..Ü.U Dr. RUSCHKE &. PAkTNER _{Pa |} ^ ^ ,. iilEA ^{1 Γηβ} · PETÄ ^{HE RM} T.I.Ion, 030 / J »JJj * BERLIN - MUNICH Tol.foo: OM / PATENT Attorneys ^H ™ ^E 080/6 49 26 Q Address: Quadrature Berlin Tigr. _mm Ad, ....: TELEX: Ιβ37ββ Munich, October 19, 1979 TELEX- "522767" LITTON INDUSTRIAL PRODUCTS, INC., 222 Roberts Street, East Hartford, Connecticut 06108, V. St. A. Claim ./ 'Throttle valve assembly for flow control at normal and high temperatures with a movable valve element that can block the flow channel, a sealing assembly that creates a bidirectional seal to the valve element, and with a recess assembly for fixing the seat rings in the valve body, characterized in that that the sealing arrangement has an elastic seat ring (31) which can be destroyed at high temperatures and a seat ring (36) made of metal which is indestructible at high temperatures, the elastic and metal seat ring protruding into the channel (12) and two seat surfaces ( 3o, 41) which create a redundant seal to the valve element (31) at normal temperatures, and that an arrangement (44) in the flow channel engages with a folded-back edge (42) of the metal seat ring in order to hold it against the 130018/0381 ORIGINAL INSPECTED To pretension the valve element and to hold it against the pressure from both sides of the valve element so that the metal seat ring offers an effective closure to the valve element in both directions at elevated temperatures at which the elastic seat ring is destroyed. 2. Throttle valve arrangement according to claim 1, characterized in that the arrangement (44) in the flow channel is an inclined surface arrangement in the flow channel at the opening of the recess. 3. Throttle valve assembly according to claim 2, characterized characterized in that the bent-back edge (42) of the metal ring (36) contains notches (45) through which the Fluids support the sealing effect in one direction can. 130018/0381