US2202735A - Corrosion resistant valve - Google Patents

Description

May 28, 1940- J. a JOHNSON 3 CORROSION RESISTANT VALVE Filed DEC. 30, 1938 Patented May 28, 1940 Y 2,202,135 CORROSION RESISTANT VALVE, John. S. Johnson, Scranton, Pa. Application December so, 1938, Serial No. 248,592 I 3 Claims. c1.251 158 The present invention relates to valves and particularly to gate valves for use in distribution systems carrying considerable volumes of water or other fluids. More particularly, the present 5 invention is directed to corrosion resistant valves.

for use in connection with chemical apparatus,

or systems carrying acids or acidulated liquids,

and has for its principal object the" provision of a valve of thecharacter described, which is l so constructed and arranged as to suffer a minimum of damage from corrosion due to contact with acid solutions. I r

It is common practice in chemical plants, and

e in other applications in which acid solutions are if) involved, to employ valves made of corrosion resistant metals, such as special chemically resist ant bronzes and the like, However, it'is the fact that few if any non-precious metals are proof against corrosion by acids, even though certain I metals and alloys have greaterresistance to corrosion than others, Moreover, such corrosion resistant materials are relatively expensive, and in certain applications involving the use of considerable numbers of large, rugged valves, the

expense of using valves constructed wholly of corrosion resistant metals is considerable. One

such application is ,found in coalmining operations, which involve the handling of large quantities of water, not only in the treatment of the coal, asin the breakers, separators, etc., but in the removal of water from the mines, etc.

It is well known that the water which is pumped from coal mines contains sulfuric acid in .solution, and infact, most of'the water available for nitely acid. lf' valves' madeof ordinary materials are employed-inhandling such waters, the

valves soon become corroded to-such an extent as to impair theiroperationyand likewise require relatively frequent replacement.

The quantity of acid to which a metal part is subjected, and hence the degree of corrosion re; sulting therefrom, is proportional to the quantity of acidulated liquid passing such part, and hence it is important, to prevent the circulation of the acidulated-Water or other liquid past the operating parts of the valve, although relatively little damage will be done by permitting a quiescent body of an acid solution to remain in contact with such parts, Whensuchsolution is comparatively dilute,

In view of the present inventionto provide a valve operating in a chamber which is separated from the conduit in such a manner as to prevent the circulation of the liquid past or in contact with the operating parts of the valve. 1

Another object is the provision of a valve of the character described, in which those parts of the valve member and valve body which are use on a large scale in coal mining regions is defiforegoing, it is an object of the subjected to the passing liquid are provided with a lining or covering of acid'resistant material, such as rubber. a I

Otherand further objects, features and advantages of the present invention will be apparent to one skilled in the art from the following description taken in connection with the accompanying drawing, in which:

Figure l is a vertical sectionon a valve constructed in accordance with the present invention; and

" Figure 2 is a-section on line 2-2 of Figure 1.

In order to facilitate an understanding of the invention, reference is made to the embodiment,

thereof shown'in the accompanying drawing and detailed descriptive language is employed. It will nevertheless be understood that no limitation I of the invention is thereby intended and that various changes and alterations are contemplated such as would ordinarily occur The valve of the present invention comprises generally a valve body 6, a valve member 20, and mechanism for operating the latter. The valve body 6 comprises an outer casing 8, of metal or other suitable material, and an inner lining 9 of vulcanized rubber or other corrosion resistant. material. The valve body isformed to provide an L-shaped fluid-passage therethrough, such passage comprising a horizontal branch I!) and a vertical branch II. The valve body is provided, adjacent the extremitiesor the respective branches I0 and. II, with flanges l2 and i3, respectively, for connecting the valve in a fluid distribution system, andit will be noted that the lining 9 overlies the outer surfaces of the flanges l2 and I3, thus providing an integral gasket for "sealing the joints between the'valve body and the adjacent conduit'sections. The valve body is 'formed' with a valve chamber M in axial alignment with one branch of the fluid passage, namely the branch I l in the illustrated embodiment. The branch ll of the fluid passage is providedwith an inwardly projecting inclined shoulder forming a valve seat l5, and the chamber 14, near its juncture with the fluid passage, is

likewise formed with an inwardly projecting inclined shoulder forming a second valve seat l6.

, It will be noted that the rubber lining 9 extends throughout the chamber M as 'well as throughout the branches l0 and II of the fluid passage. The upper'end of the chamber i4 is closed by a cover plate H, which may be bolted or otherwise suitably secured to the adjacent flange l8 of the casing 8,'a portion of the rubber lining 9 overlying the latter flange. In addition, the cover plate I! is provided with a similar lining IS, the peripheral portion of which'is clamped between the cover plate l1 and the flange l8. The valve memto oneskilled in the art to which the invention relates.

'of liquid into the chamber.

ber 20, which is reciprocably mounted in the-valve chamber l4, comprises a cylindrical metal casting 2| and a covering 22 of rubber or similar corrosion resistant material, and is formed with an outwardly and upwardly projecting flange 23 at-its upper end, the lateral surface 24 of said flange being adapted to make a fairly tight sliding fit with the inner surface of the wall of said chamber. The lower inclined surface 25 of the flange 23 constitutes a seating surface for en gagement with the valve seat I6, while the peripheral portion of the lower surface 26 of the valve member 20 is adapted to simultaneously engage the valve seat IS in the branch ll of the fluid passage. The outer diameter of the valve member 20, below the flange 23, corresponds to the inner diameter of the cylindrical wall 21 connecting the chamber l4 and thefluid passage so that the valve member makes a fairly tight sliding fit therewith.

A valve stem 28 is threaded into the upper end of the valve member 20, and is locked in place by means of a set screw 29. The stem 28 extending outwardly through the cover plate I9 is threaded throughout a major portion of its length for engagement with the internally threaded lifting nut 30, which-is secured against outward displacement by means of the shouldered sleeve 3|, the latter being bolted or otherwise suitably secured to the cover plate ll. A hand wheel 32 is rigidly secured to the lifting nut 30 for rotating the latter, the downward thrust of the lifting nut being taken by a Washer 33 positioned in a suitable recess in the upper face of the cover plate I1. The valve stem 28 is keyed to the cover plate I! by means of a key 34, to prevent rotation of the stem 28 and valve member 20. From the foregoing, it will be obvious that the valve member 20 may be reciprocated into and out of engagement with the seats l and 16 by turning the hand wheel 32 and lifting nut 30. The chamber I4 is sufiiciently long to accommodate the valve member 2| in its en tirety, so that the latter may be entirely withdrawn from the valve passage so as not to obstruct the same in any way.

When the valve member is in the positio illustrated, it will be apparent that the chamber I4 is sealed from the fluid passage l0, II not only by the engagement between the surface and the seat [6 but also by the engagement of the surface 24 with the lining 9 of the chamber and the engagement of the cylindrical ,wall of the valve member with-the surface 21 of the chamber. Thus, in effect, there is a triple seal preventing the penetration of liquid from the passage H], H into the chamber l4. When the valve is lifted to open the passage I0, I I, the seal between the surface 25 of the valve member and the valve seat 16 is broken, but the Wall of the valve member continues to engage the surface 21 of the chamber and the lateral surfaces 24 of the flange 23 continues to engage the inner surface of the main portion of the chamber, thus providing a double seal against the penetration Such liquid as may seep into the chamber during the course of time will remain quiescent therein, and will have little corrosive effect upon the valve stem 28. The latter will preferably be made of corrosion resisting metal, but it is obvious that the remaining parts of the assembly may be made of ordinary metals or other suitable materials, since they do not come in contact with the liquid standing in the chamber 14. open, no metal part is in contact with the liquid flowing through the passage I0, ll.

When the valve member 2| is fully retracted,

the upper annular surface 35 of the flange 23 is adapted to engage the upper inner surface I 9' H of the valve chamber, thus effecting an addi- Obviously, when the valve is tional seal between the fluid passage and the valve stem. The valve is thus other words, if the valve, when opened, is fully retracted, the seal between the surface 35 and the surface l9 will prevent any .leakage of fluid past the stem 28, and the usual valve stem packing may be dispensed with.

Having thus described the invention, what is self-packed, or in claimed as new and desired to be secured by Letters Patent is:

1. In a corrosion resistant valve, a valve body having an L-shaped passage and a valve chamber communicating therewith and in alignment with one branch of said passage, said branch of said passage and said valve chamber being provided with inwardlyprojecting peripheral seat portions, a valve memberreciprocably mounted in said chamber and adapted to project into said passage, said valve member having a cylindrical surface adjacent one end thereof adapted to slidably engage the inner wall of said chamber, a seating surface adjacent said'cylindrical surface adapted to engage said seat'por'tion of said chamber, and a seating surface at the opposite end thereof adapted to engage.

said passage, said passage and chamber having 'an inner lining of corrosion resistant material and said valve member having an outer covering of corrosion resistant material, and means for reciprocating said valve member longitudinally of said chamber into and out of engagement with said seats, said valve memberv having a relatively tight sliding engagement with a portion of the wall of said chamber adjacent said passage,

whereby a double seal is effected between said passage and the outer end of said chamber. 7

2. In a corrosion resistant valve, a valvebody having a passage 7 therethrough and having a valve chamber communicating with saidpassage, said valve body being formed with'an inwardly projecting peripheral. seat in said passage and'a second inwardly projecting peripheral seat in *said chamber, a valve member reciprocably' mounted in said chamber and adapted to project into a portion of said passage, said valve member having a cylindrical surface adapted to slidably engage "the inner wall of said chamber, seating surfaces adapted simultaneously to engage. said seats in said passage and said chamber, respectively, end of said member adapted to seat on and effect a seal with the upper inner surface of. said cham-' ber, and means for reciprocating said valve member longitudinally of said chamber into and out of engagement with said seats and said upper inner surface of said chamber, whereby a'seal is effected between said raised annular surface and said upper inner surface of said chamber when the valve is in fully open position.

3. A valve assembly as defined in claim 2. said raised annular surface of said valve member and said upper inner surface of said chamber consisting of corrosion resistant material.

J OHNv S. JOHNSON.

said seat portion of and a raised annular surface on the upper

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