US2471880A - Valve - Google Patents

Description

May 31, 1949. K. MacDONALD 2,471,880

VALVE Filed Nov. 2, 1945 KARL MACDWMD INVENTOR.

Patented May 3.1, 1949 2,471,880

VALVE V l "'KarL'MacDonald, WellsvillepN, Y., assignor' to Worthington Pump and Machinery Cor-para? 'tion, Harrison, N. J., a corporationof Delaware wkpplioation November 2, 1945, SerialNo; 626,256

, 31Claims, (01. 251-167) '1 This invention relates to valves, and more particularly to valve seats employed in hand operated nozzle control valves ,used on steam turbines to regulate the effective nozzle area upright wall tend-a fiatz bqttom suriacelliupozg which the valve seat rests.

As pointed out hereinbefore, considerable difficulty has been experienced in providing a lasting of a steam turbine. 5 fluid-tight seal about the valve seat 5 due to In valves of this type, the valve and valve the conditions encountered in the use of the valve seat are subject to great stresses, due to the fact structure.

that high pressure steam in the steam ring of Therefore, a novel construction of valve seat a turbine contacts one side of the valve seat, has been provided which, as clearly shown in while low pressure steam contacts the other side Figures 1 and 2 ofthe drawings, is in the form of when the valve is seated. The valve seats are made of a metal differing in expansion and con traction qualities than the metal used in a steam ring of a turbine, and it has been found in praca ring having a seat 8 against which the valve 9 rests when in closed position. The valve seat 5 has a plurality of radially extending annular ribs ll) formed thereon spaced from each other by ,tice that when the valve seat is screwed into the annular spaces II. ,The annular ribs I0 incline steam ring it leaks, due to unequal expansion at acute angles from the plane of the flat surface and contraction of the parts under temperature of the valve seat 5 which rests upon the bottom variances, and if the valve seats are shrunk into surface 1 of the opening 2, and the portion of the steam ring they become loose and conthe valve seat 5 below the lowermost annular sequently leak. space H and adjacent to the under fiat surface of It is an object of the present invention to prothe valve seat is of slightly less diameter than the vide a novel form of valve seat which will be diameter of the ribs III, as clearly shown at H tightly held in non-leaking position under all in Figure 1 of the drawings. conditions met with in its use. When assembling the valve structure, the valve With these and other objects in view, as may seat is cooled or chilled such as by Dry Ice or appear from the accompanying specification, the a deep freeze method to cause contraction thereof invention consists of various features of conso that it may be slipped into the counterbore struction and combination of parts, which will formed in the housing ll. After the valve seat be first described in connection with the achas been slipped into the counterbore of the opencompanying drawings, showing a valve of a ing 2, it will, under atmospheric temperature, preferred form embodying the invention, and expand as it heats up from its previously chilled the features forming the invention will be specifcondition, and it will form a fluidtight, firm enically pointed out in the claims. gagement between the perimeter of the ribs [0 In the drawings: and the annular wall 6. The annular ribs or fins Figure 1 is a longitudinal section through a ID will flex slightly when the valve seat 5 expands nozzle control valve of a steam turbine showing under the temperature variances encountered the improved valve seat. during the use of the valve, and therefore will Figure 2 is a perspective view of the improved not crush or become loosened in the countervalve seat. bore of the opening 2.

Referring more particularly to the drawings, It will be noted that the ribs I0 incline outthe valve housing, which in the present invention wardly towards the high pressure steam ring 3, is a P r f the Casing housing of a Steam that is, they incline outwardly towards the point turbine, is indicated at I, and it is provided with where the greatest pressure is exerted against a port 2 which establishes communication bethem so that as the housing I and the valve seat tween the steam ring 3-which contains high presare heated by the high pressure steam in the sure steam and the distribution space 4 which steam ring3 and expand, the pressure against the when the port 2 is closed contains low pressure ribs Ill will tend to force them downwardly or steam or substantially a vacuum. The opening away from the point of high pressure contact, 2 is counterbored to form a seat for the valve causing them always to maintain firm, fluid-tight seat 5, such counterbore including an annular engagement with the annular wall 6.

It will be understood that the invention is not to be limited to the specific construction. or arrangement of parts shown, but that they may be widely modified within the invention defined by the claims.

What is claimed is:

1. In combination, a valve body provided with a valve seat receiving counterbore having an annular valve seat engaging wall and a bottom surface for engagement with a valve seat, a valve seat resting on said bottom surface, said valve seat having a plurality of spaced annular ribs formed upon its perimeter and having perimetrical engagement with said annular wall, said annular ribs inclining at acute angles to said annular wall and to the face of said seat which engages said bottom surface.

2. In a nozzle control valve for steam turbines: the combination with a valve housing containing a high pressure, high temperature steam ring and a low pressure distribution space; said housing provided with an opening establishing communication between said high pressure, high temperature steam ring and said low pressure distribution space; said opening provided with a valve seat receiving counterbore having an annular 'wall and a fiat bottom surface; a valve seat seated on said fiat surface; a plurality of annular ribs formed about the perimeter of said valve seat and having perimetrical contact with the annular wall of said counterbore; said annular ribs being inclined towards said high pressure, high temperature steam ring as they extend outwardly from the perimeter of the valve seat.

3. A nozzle control valve for steam turbines as claimed in claim 2 wherein the portion of said valve seat adjacent to the bottom surface of said counterbore is of smaller diameter than the diameter of the spaced ribs and is free from engagement with the annular wall of the counterbore.

KARL MAcDONALD.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,512,496 Snead Oct. 21, 1924 1,891,460 Vlahek Dec. 20, 1932 2,174,337 Welsmiller Sept. 26, 1939

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