US2100555A - Steam pressure regulator - Google Patents

Description

NOV. 30, 1937. I j TERRY 2,100,555

SREAM PRESSURE REGULATOR Filed Feb. 11, 1935 .57EAM MAIN Elma/who'll CHARLES M. TERRY UNITED STATES PATENT ro-rrlcs STEAM PRESSURE REGULATOR Charles Terry, 'Decatur, Ill., assignor to A. W. Cash Company, Decatur, 111., a corporation of Delaware 7 l Application February 11, 1935, --Serial No. 5,991 I 2 Claims. (01. 60-545) 'This invention relates to steam pressure regunected by a link l9 to one :end of a'leverjll'. "The lators, and more'particularly'to regulators of the opposite 'end of'the lever is pivoted tothestem type having a power actuated motor which is con- 22 of the balanced valve I-2,.and the lever is suptrolled automatically in response to variations in ported intermediateitsends by a link '23 mounted 5 the pressure of steam. on the valve casing. 5

It is known practice in'this art to apply the The piston I5isactuatedby'fiuid pressureunvariable steam pressure to a flexible diaphragm, der the control of a pilot .valve'mechanism 125 .of -and to utilize the movements of thediaphragm to the four-way type connected to the ends of the actuate a pilot mechanism, such asavalve. The cylinder l4 by means of tubes 26. A suitable fluid,

l0 pilot mechanismin turn controls a' motor, which such as oil, is delivered under .pressurerto the '10 may be of the hydraulic type. Regulators of this valve mechanism 25 through a tubeiZ'I, and exconstruction are used for controlling 'stokers, haust fluid is removed through a P p The dampers, rheostats, valves, etc., and they funcvalve mechanism 25'is provided with an upwardtionwith a high degree ofsatisfactionso long as 1y pr j cting reciprocable valvestemv 29. .Fora

the steam pressure is not excessive. However, e detailedd rip i n' fx he t u -W y Valve 115 many plants today are utilizing steam at pres- "mechanism reference maybe had t the Patent sures of 500 lbs. per square inch or over. At such to Paul 0. Temple No. 1','890, granted D bigh pressures, -the diaphragm has to be made ber 13, 1932.

very thick in order to avoid rupture, and as a re- In Ord to aet etet e pilotrvelve, 'P V e a sult it lacks-the degree of flexibility necessary for h r zontal arm or lever 3| fulcrumed at ne end "20 response to slight changes in steam pressure. on e w y extending fe-edge 3 T is It is accordingly the main object of the present varm 3| s ct d by a Ve t ca 011133 onn invention to overcome these difficulties and to d of a horizontal lever 5.; he Other endo provide a steampressure regulator which can be which is connected to the valve stem 29.. T

- used with steam at very high pressures, and which lever {5531's fulcrumed on the upper end of a V '25 will respondto the slightest change in the prescal rod36, the lower end of the .rod being ,consure of t Steam nected to one end of a horizontallever ,31 ful- It is a further object of the invention to provide .orumed *at 39. The other end of-the lever 31 is .a steam pressure regulator suitable for use with Connected by .avertical linkAlJ to a horizontal so ,high pressures and so constructed and arranged projectiOn 4| m n p Of a memberlti- T is that the pressure responsive element can move member '43'is fulcrumed at 44 and v'sliltlably@ 1 with substantially no friction and wear. 7 ports aninclined rod .45'havingits ppe D With these and other objects in view, as wi otally connected to'the'piston rod I6. With this be apparent to those skilled in the art, the invenn ru ti n th 'I I 5 .W sume -.pre-deter- 35 tion resides in the combination of parts set forth mined'pos'itions in its stroke correspondingjto the "'35 in the specification and covered by the claims appositionsimparted to the arm.j3

pended hereto. Inor-d'er'to obtain the desiredautomatic opera- Referring to the drawing illustrating one emtion, means p ded to place the. arm '31 .in

bodiment of the invention, and in which like refdefinite positions corresponding to changesjin the 40 erence numerals indicate like parts, the single figst amp essu e inthe main .I'l' Withinia .prede- 4'0 "ure-is anelevation, partly in section, of a steam termined ange- FO th p p se I p ovide a pressure regulator arranged to operate a balanced piston 41 having a comparatively smalldiameter,

valve in a steam main. which is slidable vertically .ina cylindervor guide- The embodiment illustrated comprises a reguway 48. Thisjpiston is elongated and formed with -45 lator 10 arranged to control the pressure'in a a deep central recess orv pocket 49 extending "4'5 steam main or pipe line I l by means of a balanced downwardly from the p o e-p t nearly to valve l2 in the line. This valve is of theordinary the bottom thereof. A vertical strut or rod "5| double-disk type well known in the art. Steam fits loosely with n the r with i lower-end flows through the pipe in the direction of the in contact with'the bottom wall of the recess.

'50 arrow. This strut 5| carries at its upper end a knife-edge "'50 The regulator l0 comprises a cylinder l4 and a 52 W h eng the lower Surface of he arm piston l5 slidable therein forming a hydraulic -3| at a-point slightly offset laterally .from'the :motor. A piston rod 16 extends upwardly from knife-edge 32. The pressure in themain'l'lis ap... the piston l5and through a stufling box l8 at the 'Pliedto the lower surface of the piston 71 3 55 upper end of the cylinder. The pistonrod is con- "means which will be describedhereinafter, and 55 stops 51. The spring 56 is: of the coiled tension,

type, supported at its lower end by a bracket 58. The force of the spring may be adjusted by means of a wing nut 59. It will be apparent that the weights and spring serveto bias the piston 41 in a downward direction.

In steam pressure regulators as heretofore constructed the steam pressure :has been applied to" the pressure responsive element through a body of water formed by the condensing of the steam. .While this is. satisfactory for diaphragm-type regulators, ithas serious disadvantages when a piston is utilized as the pressureresponsive device. 'It is not advisable to use piston rings or other forms of packing to prevent leakage past the piston, for this will cause excessive friction and greatly reduce the sensitivity of the regulator, and yet if no packing is provided the water will leak past very rapidly, particularly at the high pressures with which the present invention is concerned. Such leakage will cause corrosion and excessive wear, which in turn will increase the rate of leakage. This leakage of condensate also represents a thermal loss, and will require special means for disposal thereof.

In order to avoid these difliculties I preferably utilize a piston 41 without piston rings or other friction producing packing devices. ,The piston may be formed witha series of spaced circumferential grooves 6| which are of value in decreasing both the leakage and the sliding friction. At the bottom of the cylinder 48 I attach areservoir 62, and the bottom of this reservoir'is connected to the steam main II by means of a pipe or conduit 63 provided with a valve 64. At installation this pipe 63 is filled with water, or it is allowed to fill with condensate from the steam, the pipe being looped downwardly in the form of a U or otherwise shaped to retain water, and the reservoir 62 is filled with oil. This oil is preferably a heavy mineral oil, an oil of the grade known as GOO-W having been found satisfactory for the purpose. .This oil floats on the water in thepipe 63v and transmits the pressure to the piston 41. Because of the comparatively 'high viscosity of thefoil, it leaks past the piston at, a very slow'rate. Atthe same timeit lubricates the piston, prevents corrosion, and increases the sensitivity of the regulator.

In'order to prevent any grit or other foreign matter from entering the cylinder 48, I preferably provide a flexible diaphragm 66 over the top of the cylinder- The central'portion of the diaphragm is secured to the strut 5|, and its peripheral portion is clamped against the regulator frame by means of an annular flange 61 at the upper end of the cylinder 48. This diaphragm serves as a lateral support for the strut 5|, as well, as a dirt excluding device. -Since the diaphragm is not under pressure, it can be made very flexible. V i r r 7 :While the leakage. of oil pastnthe piston is very small, I prefer to provide means for collectingthe oil andreturningit to the reservoir 62. For this purpose there is shown a receptacle 69 located at one side of the cylinder 48. This receptacle is provided with a sight glass 10 and a removable cover plate 1| having a vent 12 therethrough. A tube M connects the receptacle 69 with the space below the diaphragm 66, the bot- 5 tom of the receptacle being connected to the reservoir 62 by means of a pipe 15 provided with a. valve 'l6. A drain pipe 18 is connected to the reservoir near the bottom thereof, and this pipe is provided with a valve 19.

The operation of the invention will now be apparent from the above disclosure. Under normal, conditions theipiston l5 will remain stationary, with the'valve l2 partially open. The steam pressure -.in the main I the pipe 63to the oil in the reservoir 62, an through the oil to the piston 41 and the knife edge 52.- This will support the arm 3| in equilibrium againstthe loading of the Weights 53 and 54 and the spring 56. will be in neutral position. If the steam'pressure in the main increases slightly, the arm 3| will move upwardly to a new position, at the same time acting through the rod 33 and lever 35 to lower the valve stem 29 and admit'fluid to the 25 upper end of the cylinder l4, while exhausting fluid from the lower end. The piston l5 will move downwardly, and the rod 45 will swing the member 43, which will actuate the rod 40, lever 31,

rod. 36, andlever 35, raising the valve stem 29. 0 I

As soon as the pilot valve mechanism 25 reaches neutral position, the piston I5 will stop. The movement of the piston l5 will have slightly 7 closed thevalve l2 to counteract the rising steam In a similar manner, a decrease in35 pressure. steam pressure will-cause movement of the parts in the reverse direction. l

.The regulator can be constructed for very high steam pressures, and since no packing is required for the piston 41 it will respond to the :40

The oil which has escaped past the piston willhave been replaced by water the lower part of the reservoir 62, and this water will now flow out through the pipe 18, allowing the oil from the receptacle 69 to return by gravity to the reservoir through the pipe 15. As "soon as oil appears at the discharge. of the pipe 18, the operator will close the valves (9 and (S and open the valve 64, thus placing .the oil .under pressure again.

Whenever necessary, additional oil.can easilybe 0 introduced into the system byremoving the cover plate H and pouring the oil into the receptacle 69. r

Having thus described my invention, what I claim as new and desire-to secure-by Letters Pat- :6

ent is:

1. A control mechanism'for a. steam pressure regulator comprising a-cylinder, a'piston slidable in the cylinder, loading means biasing the piston in one direction, a reservoir connectedat its 70 upper end "to thecylinden; a'body of 'oil in the reservoir and in contact with the-piston, and .a

U-shaped steam pressure conduit connected to the-lower end-of-the;reservoir, the steam pres- .sure conduit serving to retain a confined body :75

will be transmitted through 15 The pilot valve mechanism 25 0 by will 14 5 oil in the reservoir and in'contact with the piston, and a U-shaped steam pressure conduit connected to the lower end of the reservoir, the steam pressure conduit serving to retain a confined body of water beneath the oil and in direct contact therewith.

CHARLES M. TERRY.

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