GB2193792A - Check valve - Google Patents

Description

GB2193792A 1 SPECIFICATION and in sealing engagement with said valve seat

surfaces, and a second position substan Check valves tially but not quite parallel to the longitudinal flow axis of said valve, and a stop member The present invention relates to check valves, 70 also mounted on said hinge pin between the and more particularly to valves used in ducts respective ears of said swing valve elements, conveying hot air. said stop member being joined to said ears For certain air handling requirements there is that project from said body disc by means a need for a simple economically fabricated disposed downstream of said hinge pin aerospace check valve capable of withstanding 75 thereby maintaining said stop member sym a proof pressure of about 250 psig at about metrically disposed relative to the longitudinal 550' F. and able to operate over a range of flow axis of said valve.

about 450' to 800' F. with reverse leakage no greater than about 0.15 Ibs.1min at 45.3 BRIEF DESCRIPTION OF THE DRAWINGS psig, at 475 F., yet having a cracking pres- 80 The invention will be better understood after sure of only about 1.5 in. H,0 differential. reading the following detailed description of

Check valves of the petal type are known, the presently preferred embodiment thereof among which are those described in U.S. Pat. with reference to the appended drawings in No. 4,079,751 (Partridge et al.), No. which:

4,230,148 (Ogle, Jr.) and No. 4,257,444 85 Figure 1 is a front elevational view of a (Ogle, Jr. et al.), these being representative of swing type cheek valve embodying the pre the group to the best of my knowledge. How- sent invention as seen from the downstream ever, all of these known valves are intended side; to operate under greater fluid pressures than Figure 2 is a sectional view taken along line those mentioned above, in particular greater 90 2-2 in Fig. 1 and showing the valve in closed cracking pressure, and have their petal ele- position in solid lines and in open position, in ments spring biased to closed position to aid. broken lines; in establishing reverse sealing. Consequently, Figure 3 is a top view of the valve of Fig.

the heretofore known valves are unsuited to 1; and the mentioned task. 95 Figure 4 is an exploded perspective view of It is an object of the presently preferred the various part making up the embodiment of embodiment of the invention to provide an Figs. 1 to 3.

improved aerospace check valve construction The same reference numerals are used of the character indicated, featuring simplicity throughout the drawings to designate the of construction and maintenance, and imsame or similar parts.

proved performance, as compared to existing constructions. DETAILED DESCRIPTION OF THE PRESENTLY

A specific object is to achieve the above PREFERRED EMBODIMENT object with a construction having a very low Referring now to the drawings, the new cracking pressure, yet able to establish an ex- 105 check valve is shown as having a circular cellent seal against air leakage under moderate body disc 10, with a diametral web 11 separ operating pressure and moderately high tem- ating two back-to-back D- shape openings 12 perature as well as being capable of with- and 13 through the disc 10. The disc may be standing a substantial reverse pressure. considered as having an upstream side 14 and The embodiment comprises a valve con- 110 a downstream side 15 with valve seat sur- struction without biasting springs that, never- faces 16 and 17 bordering the openings 12 theless, functions effectively to accomplish the and 13, respectively, on the downstream side.

mentioned objectives. A pair of parallel ears 18 and 19 project from In accordance with the invention there is the body disc 10 on the downstream side 15, provided a swing-type check valve comprising 115 one ear at either end of the web 11.

in combination a circular body disc with a di- A hinge pin 20 is supported spaced down- ametral web separating two back-to-back D- stream of and parallel to the web 11 with the shape openings through the disc, said disc ends of the hinge pin secured in apertures 21 having an upstream and a downstream side, and 22 in the respective ears 18 and 19. A valve seat surfaces bordering said openings 120 pair of swing valve elements or petals 23 and on said downstream side, a pair of parallel 24, each formed with a pair of spaced apart ears projecting from said body disc on the ears, 25, 26 and 27, 28, respectively, are downstream side, one at either end of said journaled by their respective ears on the hinge web, a hinge pin with opposite ends mounted pin 20, over an interposed sleeve bushing 29 in said ears supporting said pin spaced down- 125 or 30, respectively.

stream of and parallel to said web, a pair of A stop member 31, somewhat T-shape, has swing valve elements each having a pair of two bores, 32 and 33, formed therein sub spaced apart ears journaled on said hinge pin stantially as shown, the stop member 31 is with said valve elements rotatable about said also mounted on hinge pin 20 which passes hinge pin between a first position parallel to 130 through the bore 32. The member 31 is lo- 2 GB2193792A 2 cated between the ears 25 and 28 of the surfaces bordering said openings on said swing valve elements 23 and 24. In addition, downstream side, a pair of parallel ears pro the stop member 31 is joined by separate jecting from said body disc on the down means in the form of a pin 34 to the ears 18 stream side, one at either end of said web, a and 19 that project from the body disc 10. 70 hinge pin with opposite ends mounted in said The pin 34 is disposed downstream of hinge ears supporting said pin spaced downstream pin 20, passing through the bore 33, with the of and parallel to said web, a pair of swing pin ends secured in the corresponding aper- valve elements each having a pair of spaced tures 35 and 36. apart ears journaled on said hinge pin with The pins 20 and 34, except for the knurling 75 said valve elements rotatable about said hinge adjacent one end of each, have an outside pin between between a first position parallel diameter that makes a sliding fit within the to and in sealing engagement with said valve receiving apertures 21, 22 and 35, 36, re- seat surfaces, and a second position substan spectively. However, the knurled zones have tially but not quite parallel to the longitudinal an enlarged diameter such as to make a press 80 flow axis of said valve, and a stop member or force fit within the receiving aperture. The also mounted on said hinge pin between the radially outward mouth area of each of the respective ears of said swing valve elements, apertures 22 and 36 is staked over to prevent said stop member being joined to said ears the respective pins 20 and 34 from backing that project from said body disc by means out of the aperture. Nevertheless, if through 85 disposed downstream of said hinge pin use it becomes necessary to replace parts of thereby maintaining said stop member sym the valve, the pins can be driven out of their metrically disposed relative to the longitudinal sanctuary in apertures 22 and 36, overriding flow axis of said valve.

the staking. 2. A swing-type check valve according to For ensuring long life and resistance to cor- 90 claim 1, wherein each of said swing valve ele- rosion, it is presently preferred to form all of ments is journaled on said hinge pin over a the components of corrosion resistant steel, sleeve bushing.

e.g., type 17-4 PH. In addition, the valve seat 3. A swing-type check valve according to surfaces 16 and 17, all surfaces of the bush- claim 1 or 2, wherein the ears of said swing ings 29 and 30 except for the bores there- 95 valve elements are located at unequal dis through, and the surface of the pin 20 except tances from a valve element centerline for the knurled zone, are all provided with a whereby when said pair of swing valve ele thin coating of chromium. ments are mounted back-to-back, the ears on As best seen in Fig. 2, the stop member 31 one swing valve element intercalate with and has side walls 37 and 38 inclined or tapered, 100 fit adjacent the ears on the other swing valve each approximately 5' from the plane that element with all of the apertures through said contains the centerline of the bores 32 and ears aligned along a common axis.

33. When valve elements 23 and 24 swing to 4. A swing-type check valve substantially valve open position due to a positive pressure as herein described with reference to the ac differential between the upstream and down- 105 companying drawing.

stream side of the disc body 10, the elements 5. A check valve having two valve ele- 23 and 24, being unimpeded by springs or ments arranged to be rotatable in opposite linkages, will swing back against side walls 37 senses between a first condition in which the and 38 of stop 3 1. The stop prevents the valve elements extend oppositely to one t valve elements from assuming a fully open 110 another and a second condition in which the parallel position in which they would be unsta- valve elements extend substantially but not ble and not assured of closing when the fluid quite parallel to each other.

flow reverses. However, being retained 5" from "dead center", a slight air flow in the Published 1988atThe Patent Office, State House, 66/71 High Holborn, London WC1R 4TP. Further copies may be obtained from reverse direction will pick up the elements 23 The Patent Office, Sales Branch, St Mary Cray, Orpington, Kent BR5 3RD.

and 24 and force them to the closed position. Printed by Burgess & Son (Abingdon) Ltd. Con. 1/87.

Having described the present invention in terms of the presently preferred embodiment thereof, it should be apparent to those skilled in the subject art that numerous changes in construction can be introduced without depart ing from the true spirit of the invention as defined in the appended claims.

Claims (1)

1. A swing-type check valve comprising in combination a circular body disc with a diame tral web separating two back-to-back D-shape openings through the disc, said disc having an upstream and a downstream side, valve seat