US2157554A - Foot valve for pump suction lines - Google Patents

Description

May 9, 1939. w. K. McFARLlN FOOT VALVE FOR PUMP SUCTION LINES 2 Sheets-Sheet 1 Filed Jan. 5, 1938 INVENTOR. av ijygizv BY I ; ATTORNEY.

2 Sheets-Sheet 2 ebb 'upoooLL/Lp% earl/Ill W. K. M FARLIN FOOT VALVE FOR PUMP SUCTION LINES Filed Jan. 3, 1958 ULULDQOOD May 9, 1939.

Patented May 9, 1939 v I UNITED STATES PATENT OFFICE FOOT VALVE FOR PUMP SUCTION LINES William K. McFarlin, East Orange, N. J.

Application January 3, 1938, Serial No. 182,959

Claims. (01. 277-60) This invention relates to improvements in loot portion of said plate are valve port means, prefvalves for pump suction lines. erably comprising two rectangular openings I2,

The invention has for an object to provide a respectively offset on opposite sides of a medial foot valve structure of maximum capacity in reportion of said plate.

5 lation to a given size thereof; the same being Mounted on the upper side of said plate II is 5 equipped with a novel construction and arrangea check valve housing formed to provide a subment of check valve means and check valve stantially rectangular chamber above the valve chamber or housing therefor, whereby restricport openings I2, having opposite side walls I3 tion of fluid movement under pump suction is respectively parallel to the outer long sides of said reduced to a minimum so that substantially unvalve port openings I2, and having outwardly impeded movement of fluid to the suction line at bowed opposite end walls I4 in outwardly spaced maximum volume is assured. relation to the ends of said valve port openings Another object of the invention is to provide a I2. Said housing is provided with an outwardly combined foot valve and strainer structure projecting longitudinal peripheral footing flange wherein the strainer possesses an open area exi5 extending from the lower margins of said walls 5 ceeding many times the suction area of the valve. I3I4. The upper margins of said walls I3--I i Another object of the invention is to provide terminate in a t p Wall W c merges in a a check valve means comprising flexibility hinged cular upwardly projecting neck-portion II, havvalve flap means of rectangular form adapted to an e a internally wh ead d union provide a maximum extent of hinging length and portion I8 into which is screwed the externally 0 consequently of greater durability 'and longer threaded end of the pump suction line or pipe I0,

serviceable life; the valve fiap construction and thereby to operatively Connect t e OOt Va ve and arrangement being such that the flap means is strainer structure therewith,

cut from a single sheet of flexible and elastic Overlaid upon the upper side of said plate I I material, such as rubber, whereby outlying poris a combined valve flap and a et means made 5 {ions of said sheet may be utilized as a gasket Of flexible elastic sheet material, such as sheet between the foot valve housing and strainer secrubber of substantial thickness, the same comti f th d ice, prising a gasket portion l9 shaped to conform to Other objects of this invention, not at this the bottom peripheral outline of said check valve time more particularly enumerated, will be unhousing, and in Width Co p d Substantial- 30 derstood from the following detailed description y to the Width 0f the ot fla e l5 0f the of th same, latter. Integrally formed with and springing An illustrative embodiment of this invention fr m the i ner m r n f said gasket p n I9 is shown in the accompanying drawings, in Which border the side walls I3 of said check valve hi h; housing are rectangular inwardly extending valve Fig 1 i a t nd ie of a f t valve d flaps 26, the same being somewhat larger in area strainer device made according to this invention; than the areas of the VELIVe p Openings Over Fig. 2 is a vertical transverse section through the Which y respectively tend in normal closed ame taken on line 2-2 in Fig 1, but drawn on 11512111011 thereto. The portions 2| by which said 40 an enlarged scale; Fig. 3 is a horizontal section, Valve fl p 20 j the gasket portion l9 p ov de 40 taken on line 3--3 in Fig. 2; and Fig. 4 is a fragsaid valve with relatively long flexible hinging mentary vertical section, taken on line 4-4 in connections, thereby assuring greater ra il ty Fig. 1, but drawn on an enlarged scale. and longer serviceable life, as well as greater con- Similar characters of reference are employed tlol and Stability of Valve p eme ts to asin the above described views, to indicate corresure proper and oper registration a a 45 sponding parts. ment of the valve flaps with the valve port open- Referring to the drawings, the reference char- S- The dy portions of the Volvo halls e acter l0 indicates a pump suction line or pipe to p f ly main in d n fl pl in t curlwhich the novel foot valve and strainer structure i s. uckling or o h r similar d formati n, by

i n ted, providing the same with top and bottom reen- 5 The foot valve and strainer structure comprises o g and stiffening p ates 2 and 23, which are a horizontal valve port plate II, which also prefsecured thereto by rivets 24 or other suitable faserably forms the top end wall of the strainer eletening means. Preferably the top plates 22 are ment. The plate II is preferably of rectangular somewhat larger in area than the areas of the peripheral shape. Opening through the central valve port openings I2, while the bottom plates 55 23 are of smaller area than said valve port opening areas.

The check valve housing, valve port plate II and intermediate gasket and valve flap structure are secured together in operative assembled relation by means of bolts and nuts 25 which are engaged through the latter parts and through the footing flange [5 of said check valve housing.

Suitably affixed to the underside of said plate 5 l, as by welding for example, is a strainer cage 26 of square cross-sectional shape and outwardly offset relative to the vertical axis of said checkvalve housing pump suction line to a substantial extent, whereby a maximum of strainer area proportional to the suction area is provided so that the former is many times in excess of the latter. The walls of the strainer cage are perforated by a multiplicity of suitably disposed and preferably vertical slots 27. The lower end of said strainer cage is closed by a bottom plate 28 suitably affixed thereto by Welding or other suitable fastening means. Said bottom plate 28 is ordinarily imperforate, especially when the device is to be used resting upon bottom of the area to be drained. If, however, the device is to be used in clear water or elevated from the bottom of the area to be drained, perforations may be provided in said bottom plate 28 to further increase the strainer area relative to suction area of the de vice.

Depending from the plate ll downwardly into is interior of the strainer cage, but terminating short of the bottom plate 28, is a suction intake tube 2Q which communicates with the valve port openings 12 of said plate ll. Said tube 29 is affixed to plate H by welding or any other suitable fastening means.

Affixed to and extending across the underside of said plate I i, intermediate the valve port openings i2, is a reenforcing rib or brace 3i], preferably of angular cross-sectional shape, with the free margins of its flanges welded to the plate I 5.

When the device is in operation, on the suction stroke of a pump attached to the suction line Ill, the valve flaps 263 will swing upward to open positions shown by dotted lines in Fig. 2. By an inspection of Fig. 3 it will be noticed that the construction of the check valve housing chamber provides flow clearance passages 3i ofiset around the ends of the rectangular valve flaps 20 in addition to the axial flow passage 32 lying intermediate the free sides of said valve flaps. By this novel arrangement a maximum flow by-pass area is provided around the open valves which is calculated to permit substantially unimpeded movement of fluid around the open valve flaps and to the suction line at maximum volume. By the a1 rangement, as thus devised, about one-half the flow capacity is furnished around the ends of the valve flaps and through the additional flow clearance passages 35, while the other half of the flow capacity is furnished by the axial passage 32 intermediate the free sides of said valve flaps.

By reason of the novel combination of flow clearance passages 3| in conjunction with the axial flow passage 32, it is found that the valve flaps 2d are not required to swing so high, and consequently not only is there less wear and tear stresses and strains applied to the hinging connections of said valve flaps, but it is also possible to reduce the height of the check valve chamber, thus permitting the use of lower chamber castings with consequent economy in material and manufacturing costs in the production of the device.

While I have shown the novel foot valve and strainer structure equipped with a duplex arrangement of check flap valves, it will be appreciated that the principles of construction involved may also be provided in a single check flap valve form, especially in smaller sizes of the structure.

From the above it will be apparent that a sturdy, durable and yet highly efiicient foot valve structure is provided by the instant invention, as well as one having a maximum of discharge capacity as sized to accommodate lines of given suction area. I am aware that many changes could be made in the foot valve and strainer structure above described and as shown in the accompanying drawings, and that many apparently widely different embodiments of this invention could be made without departing from the scope thereof as defined by the following claims. It is therefore intended that all matter contained in the above description or shown in the accomwardly spaced from the respective ends of said port, thereby providing flow clearance passages contiguous to said port ends, said housing memoer walls merging into an upwardly projecting neck-portion having means to connect the same with the end of a pump suction line, and a unitary valve flap and gasket means having its gasket portion interposed and secured between the housing member and valve port plate and providing a rectangular valve flap exceeding the area of and adapted to overlie said port, the integral connection between said valve flap and gasket portion providing a long hinging portion coextensive with the width of said valve flap and contiguous to the housing member side wall which is adjacently parallel to one side of said port as aforesaid, said unitary valve flap and gasket means being made of elastic sheet material.

2. In a foot valve structure as defined in claim 1, wherein said valve port plate extends substantially outward beyond and around said depending from said valve port plate in alignment with the port thereof and terminating short of the bottom of said cage.

3. In a foot valve structure for pump suction lines, a valve port plate having a pair of spaced rectangular ports, a housing member above said plate having side walls respectively adjacently parallel to the respective outer sides of said ports and interconnecting walls angular to said walls and respectively outwardly spaced from the respective ends of said ports thereby providing flow clearance passages contiguous to said port ends, the area of said housing member interior intermediate said ports providing an axial flow passage with which said flow clearance passages join, said housing member walls merging into an upwardly projecting neck-portion having means to connect the same with the end of a pump suction line, and a unitary valve flap and gasket means having its gasket portion interposed and secured between the housing member and valve port plate and providing rectangular valve flaps exceeding the areas of and adapted to respectively overlie said ports, the integral connections between said valve flaps and gasket portion providing said valve flaps with long hinging portions coextensive with the widths of said valve flaps and respectively contiguous to the respective housing member side walls which are adjacently parallel to the outer sides of said ports, said unitary valve flap and gasket means being made of elastic sheet material.

4. In a foot valve structure as defined in claim 3, wherein said valve port plate extends substantially outward beyond and around said housing member, a strainer cage depending from the marginal portions of said valve port plate, and a. suction intake tube also depending from said valve port plate within said strainer cage and communicating with said valve ports, said tube terminating short of the bottom of said cage.

5. In a foot valve structure as defined in claim 3, wherein said axial flow passage and said flow clearance passages are so relatively dimensioned that approximately one-half of the flow discharge through the valve ports when the valve flaps open is accommodated by the axial flow passage and the other half of said flow discharge is accommodated by said flow clearance passages.

WILLIAM K. MCFARLIN.

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