US2031445A - Automatic regulating apparatus for steam heating systems - Google Patents

Description

Feb.'l8, 1936. v E. c. WILEY 2,031,445

AUTOMATIC REGULATING APPARATUS FOR STEAM HEATING SYSTEMS Original Filed June 15, 1930 2 Sheets-Sheet 1 I limentm- Ed a Wiley h (Ittorncg Feb. 18, 1936. E. c. WILEY 2,031,445

AUTOMATIC REGULATING APPARATUS FOR STEAM HEATING SYSTEMS Original Filed June 15, 1930 2 Sheets-Sheet 2 3nnentor EaQaMfiZ A; (Ittorneg Patented Feb. 18, 1936 UNITED STATES AUTOMATIC REGULATING APPARATUS FOR STEAM HEATING SYSTEMS Edgar C. Wiley, Lynchburg', Ya, assignor to Simplex Heating Specialty Company, Inc., Lynchburg, Va., a corporation of Virginia Original application June 13, 1930, Serial No. 460,952. Divided and this application June 24,

1932, Serial No. 619,138

6 Claims. (01.236-80) This invention relates to automatic regulating apparatus for steam heating plants. A general object of the invention is to provide an extremely sensitive and accurate pressure and flow regulating apparatus which may be controlled automatically or manually from a remote point by a pressure sensitive agent. Other objects will be apparent from the following description.

This application is a division of my copending application Serial No. 460,952, filed June 13, 1930, now Patent No. 1,868,555 dated July 26, 1932, in which the present invention is described as a part of a regulating system for a steam heating plant.

In the accompanying drawings forming a part of this specification;

Fig. 1 is an elevation partly in section of'the regulating apparatus to be described;

Fig. 2 is an enlarged vertical section through the pilot valve shown at the extreme right of Fig. 1; and I Figs. 3 and 4 are enlarged sectional elevations of parts shown at the extreme left of Fig. 1.

Referring particularly to the drawings, there is shown a section of a high pressure steam main 5 through which steam may be supplied from a central station, a low pressure main 6 from which the heating units may be supplied, and a reducing and regulating valve 1 by means of which the quantity of steam passing from the high to the low pressure main is regulated. On either side of the reducing Valve 1, there is located a gate valve 8 by means of which the reducing valve may be shut off from both the high and low pressure mains.

The regulating valve is of the balanced type having upper and lower valve seats 9 and Ill and a double headed valve plunger l I. The area .of the upper valve head is slightly larger than that of the lower so that the valve is urged by the steam pressure towards open position. This tendency is overbalanced by a valve spring I2, which, of course, is replaceable with other springs or'with weights.

Secured to'the underside of the valve body 1 is a housing l3 having a longitudinal bore l4 and enclosing an elongated valve operating stem l5. The stem is suitably guided for reciprocation'in the bore by guide member IS. The lower end of the housing l3 terminates in the half portion of a diaphragm casing I1, and between the half portions of the casing ll, a diaphragm is firmly clamped. The lower end of the valve stem is secured to the diaphragm as shown at l8 so that flexing .of the diaphragm will reciprocate the valve member ll.- Communication between the upper portion of the diaphragm casing and a point in the low pressure main is provided by the bore l4 and a short pipe [9 so that the upper portion of the diaphragm I8 is at all times subjected to a steam pressure substantially the same as that in the low pressure main. The underside of the diaphragm is subjected to a variable steam pressure through a pipe having a connection with a pipe 2| which is used to bypass a small quantity of steam for control purposes from a point in the high pressure main around the regulating valve to a point in the low pressure a I Between the high pressure end of the pipe 2| and 'its connection with the main, there are inserted a strainer 22, a reducing valve 23, and an orifice member 24, best shown in Figs. 3 and 4. The strainer is of a standardconstruction havinga removable screen to prevent the passage of foreign material through the control system. The reducing valve 23- provides a means of reducing the pressure of the steam entering the pipe 2l and maintaining it constant at something in excess of the maximum to be carried in low pressure main 6, in spite of pressure variations in the high pressure main, which Variations may be large. As shown in Fig. 4, the reducing valve comprises a two part body 24, between the parts of which a pressure diaphragm 25 is clamped along its edges, Screwed into the body 24 is a housing 26 enclosing a powerful coil spring 21 which presses downwardly against the diaphragm. The pressure exerted by the spring may be adjusted by means of the regulating screW 28. The underside of the diaphragm carries a yoke 29 which extends downwardly nearly to the bottom of the valve body and carries a removable valve member 30 which moves toward and away from the v'alve port 3! as the'diaphragm flexes responsive to changes in steam pressure within the valve body. A guide 32 is provided to guide theyoke 29 in its movements and a removable plug 33 holds the guide 32. The pressure exerted by the spring 21 may be adjusted to balance any desired steam pressure, within limits, within the body 24 such that a substantially constant flow of steam enters the valve body at a pressure suitably reduced for the purpose desired.

A short length of pipe 2 l connects the reducing valve 23 with the orifice member 24. This member connects with the pipe '2l through a narrow orifice 34 in. a plug 35 screwed into the bottom of the chamber 36. The use of this orifice insures a smaller flowiof the steam than could be obtained by the reducing valve 23 alone. To facilitate cleaning of the orifice in case of clogging, a cleaning needle 31 is provided, which is carried by a stem 38 reciprocable in the housing 33; and said cleaning needle is normally held in the raised position shown by av coil spring 40 which acts against a cap 4|. By depressing the cap 4|, the needle will be forced down through the orifice so as to dislodge any foreign material which might collect therein.

At a suitable point in the bypass pipe 2| a pressure gauge 42 of standard construction is provided for the operators use in checking and adjusting the pressure in the control pipe 2i.

The opposite end of the pipe 2| is connected with a pilot valve 43, and the valve 43 is eonnected to the low pressure main through ashort pipe 2| The purpose of the pilot valve is to control the opening and closing of the regulating valve 1, said pilot valve being movable responsive to a governing fluid pressure, as will'be described, and hence being regulatableby temperature variations, if desired, as fully disclosed in the parent application.

The pilot valve 43, shown in detail in Fig. 2, has a valve chamber 44 open to the low pressure main through the pipe 2|", a nipple 45 screwed into the top of the chamber, and another nipple 46 screw-threaded therein having a union 4'!- with the pipe 2|, and a valveseat member 48 at the inner end of nipple 45.

The valve head 49 is carried on a valve stem 50 which is reciprocable in the longitudinal bore 5| of a coupling member 52 screw-threaded into the'bottom of the valve chamber. The head 49 is not rigidly secured to the stem 50, but is held thereon by a cross pin 53 through the'stem which engages a hole 54, in the head, somewhat larger than the pin. Between the head and another cross pin 55 a small coil spring 56' acts to hold the head normally inthe position shown in Fig. 2.

Secured to the enlarged'head' 51 of the coupling 52 is a casing 58 enclosing a bellows 59 which serves as an operating means for the valve stem 50, the valve stem passing through the center of the bellows and having its lower end slidably received in the guide bore 66 in the lower end of the casing. The upper end of the bellows is secured to a head 6| which has an integral nipple 62 screw-threaded into the bore 5!. The bore of the nipple is considerably larger than the diameter of the valve stem, as is the bore 5|, so that steam in the valve chamber 44 has free access to the interior of the bellows. No steam can escape, however, to the exterior of the bellows inside the casing 58. The lower end of the bellows has a head 63 to which the lower portion of the valve stem 50 is threaded or otherwise secured. Thus on expansion and contraction of the bellows, the valve head 49 will be moved away from and toward the valve seat 48. A spacing sleeve 64" is. arranged in the bellows surrounding, the stem 5|! between the heads 6| and 63 for a purpose to be described.

An inlet port 65 is provided in the. casing 58. through which a fluid. may be conducted from. a tube 66 to act on the exterior of the. bellows. As disclosed in the parent application, the tube. 66 may be filled with oil and may communicate with any automatic pressure fixing device in which the pressure varies, in proper ratio, to changes in. the temperature outside. orinsidev of abuilding which is heated from. the low pressure. main 6 01 may communicate with any manually controlled pressure source. With such an arrangement the pilot valve 49 will open and close with pressure changes in pipe 66 and in turn will vary the position of the regulating valve plunger I to increase or reduce the steam flow into the low pressure main accordingly. However, almost any kind of fluid, either liquid or gaseous, might be used to exert pressure against the exterior of the bellows 59, and, in some cases, a mechanical agent, such as a screw adjustable spring like that used to press against the diaphragm 25, might be employed without departing in any way from the scope of the invention. When a fluid is used to transmit pressure against the exterior of the bellows 59, the pressure source may be near at hand or when air is used to transmit such pressure, the source may be at a remote point, as a building located several blocks away.

When the valve 49 is seated, the bellows 59 cannot push the valve stem farther up so as to fully compress or jamb the spring on account of the sleeve 64; and if an excessive pressure should be accidentally built up in the pressure tube 66 which would, without the protection of the spring, back up too much pressure in pipe 2| (as hereinafter explained) such excess pressure in pipe 2| would be relieved at the valve 49 by a further compression of the coil spring 56 underneath said valve, thus acting as a. safety valve to relieve such excess pressure in pipe 2| and to protect against the possible rupture of diaphragm l8 as will be described (see Fig. 1).

It will be apparent that steam will condense and collect in certain parts of the system. Thus condensate collects on both sides of the diaphragm l8 and serves as a protection to the diaphragm against live steam. To insure sufficient volume of condensate in the pipe 20, a condensation chamber 2|] is provided. Condensate also collects in the bellows 59, producing a slight head of Water in addition to the steam pressure in the chamber 44. In some cases, it may be desirable to neutralize this head, and this may be accomplished by providing a small coil spring (not shown) in the bore 60 to act upwardly against the valve stem 50.

As previously stated, the pipe |9 (Fig. 1) connects the low pressure main 6 with the space above diaphragm I8, and when the pilot valve is open, the low pressure main 6 is also connected through pressure tube 2| and pipe 20 with the space below diaphragm I8, so that the pressures on opposite sides of said diaphragm are practically balanced, irrespective of the degree of the pressure in main 6. The continuous small flow of steam through tube 2| in no way affects this balancing of pressures on oppositesides of diaphragm l8 when the pilot valve is open. As soon, however, as the pilot valve is. closed to interrupt the flow of steam through pressure tube 2|, an excess pressure will be built up in tube 2| and will operateagainst the lower side of diaphragm |8 to overbalance the pressure on the opposite side of the diaphragm and to open the regulating valve against the resistance of spring Whatever the nature of the fluid used in the casing 56, a small change of pressure in the tube 66 will be multiplied many times in its effect on the pressure backed up into tube 2| and its lifting power on diaphragm l8 to open or close the regulating valve 1.

Assuming that regulating valve 1 is in closed position and that a very low governing pressure,

of only one ounce is appliedto tube 66 the sensi-. tive operation of the control system may be understood by reference to Figs. 1 and 2 as follows:

Since the area of the port leading to pressure tube 2| and closed by the pilot valve head 49 is very small, say 1/20th of 1 sq. in., and since the area of the bellows head 53 may be 2 sq.'in., an upward governing pressure. of 1 oz. per sq.-in. applied to tube 66 will create an upward lift of 2 oz. on bellows head 63,-which lift is communicated to valve head 49 to hold it against its seatto obstruct the flow of steam through pressure tube 2| with such force as to create a pressure of 40 ounces per sq. in. in tube 2|, and on lower side of diaphragm I8. This unbalanced pressure of 40 oz. (2 lbs. per sq. in. acting on the relatively large surface of diaphragm I8 is much more than ample to open regulating valve 1 against the pressure of spring l2. This opening of valve I will permit steam to pass into low pressure main 6 and through pipe 21* (Fig. 2) into pilot valve 43 and hence into bellows 59. When the pressure inside of bellows 59reaches 1 oz. per sq. in., the lifting effect of the fluid pressure in casing 58 will be overcome and pilot valve head 49 will open, which in turn would release the excess pressure in tube 2! and allow spring I2 to close the regulating valve 1 or to bring about astate of stabilization in its operation at one ounce pressure. Any higher pressure can, of course, be produced in the same way by applying the desired governing pressure to pipe 66.

The regulating arrangement is equally sensitive to pressure variations of one ounce or less when operating to carry any higher pressure in main 6. Referring again to Figs. 1 and 2, this may be illustrated as follows:

Assuming that regulating valve 1 is in operation with a governing pressure of 5 lbs. on tube 66 and maintaining a pressure of 5 lbs. in low pressure main 6. Under this condition the pressures in the space above diaphragm l8 would be 5 lbs. The pressures on the inside and outside of pilot valve bellows 59 would be so nearly balanced at 5 lbs. that pilot valve head would be barely closed with an upward pressure of only a fraction of an ounce which would impose a resistance to steam coming through pipe 2| sufficient to boost the pressure in pipe 2! and in the space below diaphragm I8 a possible lb. above the normal pressure of 5 lbs. existing in the space above the diaphragm, this excess pressure below the diaphragm being sufiicient to balance or overcome the resistance of spring l2 and to maintain just the proper opening of regulating valve plunger II. In practice the slightest variations in the balance of the pressures on the inside and outside of bellows 49 are multiplied in their effeet on the pressure below diaphragm I8 to preserve just the proper degree of opening of valve plunger H to maintain the desired pressure in low pressure main 6.

Thus it will be seen that the regulation of pressures in low pressure main 5 is governed entirely by the relation between the pressures on the inside and outside of bellows 59 in such a way that the pressure in low pressure main 6 and inside of bellows 59 will always be equal to the pressure applied to the exterior of the bellows 59 through pressure pipe 65 since the efiective areas of the inside and outside of the lower bellows head are practically the same.

remote control of steam flow is desired. That the control system will have other applications in various classes of fluid conducting systems will be apparent, however, to those skilled in the art.

'Obviously, the present invention is not restricted to the particular embodiment thereof herein shown and described. Moreover, it is not indispensable that all the features of the invention be used conjointly, since they may be employed advantageously in various combinations and sub-combinations.

What I claim is:

1. Regulating apparatus for steam heating systems and the like comprising, in combination, a high pressure main; a low pressure main; a regulating valve controlling flow of steam into the low pressure main; a pilot valve connected with the low pressure main; means for supplying a substantially constant but very small flow of steam to the pilot valve from the high pressure main; said pilot valve stopping said flow of steam when closed; means to operate said pilot valve; operating means for the regulating valve so constructed and connected with the pilot valve that it is controlled by action of the pilot valve, said operating means opening the regulating valve when closing of the pilot valve builds up enough pressure; said means for supplying a very small flow of steam to the pilot valve being directly connected with said operating means; and a pipe connecting the low pressure main with the aforesaid operating means, so that the pressures on opposite sides of said operating means are practically balanced irrespective of the pressure in the low pressure main. 7

2. Regulating apparatus for steam heating systems and the like comprising, in combination, a high pressure main; a low pressure main; a

regulating valve controlling flow of steam into the low pressure main; a movable member; means to move said member; a pilot valve connected with said member so as to be closed when the member is moved; means for delivering a small quantity of steam at substantially uniform pressure to one side of the pilot valve, the other side of the pilot valve being connected to the low pressure main; pressure-actuated means for opening said regulating valve; a spring for closing said regulating valve; a pipe connecting the low.pressure main with one side of the pressureactuated means; and a second pipe connected to the steam delivering means and also to said pressure-actuated means, so that when said pilot valve closes and builds up a pressure in said steam delivery means and in said pipe, the pressure-actuated means will be operated so as to open the regulating valve to deliver more steam into the low pressure main.

3. In a fluid transmission system having a high pressure main and a low pressure main, a regulating valve of the balanced type controlling the fiow of fluid into the low pressure main; a housing secured to the regulating valve; a valve stem in the housing; a diaphragm casing secured to the housing; a valve operating diaphragm fastened to said valve stem and dividing said casing into two parts; a bypass pipe having its opposite ends connected to said high and low pressure mains at points on opposite sides of said regulating valve; means to supply a very small volume of fluid at a regulated pressure from the high pressure main to the bypass pipe; a pipe con nection adapted to transmit the fluid pressure in the low pressure main to one side of said valve operating diaphragm; a pipe connection, adapted to transmit a balancing fluid pressure from a point in said bypass to the opposite side of said diaphragm; and means in said bypass line responsive to the pressure in said low pres-- sure main and also responsive to an independent pressure agent to change the pressure on one side of said diaphragm, thereby to change the setting of said regulating valve; the pressure on said diaphragm being self-balancing after adjustments in the valve setting have occurred.

4. A fluid transmission system comprising, in: combination, a high pressure main; a low pressure main; a regulating valve governing the flow of fluid from the high into the low pressure main; said valve having an operating mechanism comprising a valve stem and a suitably encased diaphragm operable to reciprocate the valve stem responsive to pressure differences on the oppositesidesthereof; a pipe connected to bypass a small amount of fluid from a point in the high pres-- sure main around the regulating valve toa pointin the low pressure main; means to regulate the pressure in said bypass pipe; means to restrict the flow of fluid in said bypass pipe to a very small volume; said diaphragm being subject, on one side, through a pipe connection, to the pres-- sure in said low pressure main, and on the opposite side, through another pipe connection, to the pressure in said bypass pipe; and a pressureresponsive pilot valve and operating means therefor connected to said bypass pipe to change the pressure on one side of said diaphragm, thereby to change the position of said regulating valve relative to the valve seat.

5. A fluid transmission system comprising, in combination, a high pressure main; a low pressure main; a reducing valve regulating the flow of fluid into the low pressure main; said valve having an operating mechanism comprising a valve stern and a diaphragm operable to recipmate-the stem responsive to pressure difierences on theopposite sides thereof; a pipe connected to said mains to bypass a small flow of fluid around said regulating. valve and having a branch pipe communicating with one side of said diaphragm; another pipe adapted to transmit the fluid pressure in the low pressure main to the Opposite side of saiddiaphragm; means to regulatethe flow o1 fluid into said bypass pipe; and means responsive on one side to the fluid pressure in said low pressure main, and on the other side to an independent pressure agent to interrupt the steam flow in said. bypass pipe, thereby to change the pressure on one side of said diaphragm. so as to open: or close said regulating valve. 1

6. A fluid transm'nsion system comprising a high pressure main; 9, low pressure main; a spring urgedxreducingivalve having an operating diaphragm regulating theflow into said low pressure main; a bypass; pipe around said regulating valve; means transmitting the fluid pressure in said low pressure main to one side of said valve operating diaphragm; means transmitting the fluid-pressure in. said bypass pipe to the opposite side-oi said diaphragm; a pilot valve in the low pressure end-:ot said bypasspipe, said pilot valve having an operating means; means transmitting fluid pressure from the low pressure main to one side of said pilot valve operating means; and;temperature-responsive means acting on the other side of said pilot valve operating means; opening and closing of said pilot valve causing pressuredifferemes on the opposite sides of said diaphragm operable to open or close said regulati-ngvalve;

EDGAR C. WILEY.

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