US1871044A - Automatic discharge valve - Google Patents

Description

Aug# 9, 1932 D. N. cRosTHwAlT. JR., ET AL 1,871,044

AUTOMATIC DISCHARGE VALVE Filed Deo. 51, 1928 3 Sheets-Sheet 1 ug- 9, 1 932- D. N. cRosTHwAl-r` JR., ET AL 1,871,044

AUTOMATIC DISCHARGE VALVE Filed Dec. 5'1. 1928 3 Sheets-Sheet 2 lllll 55m/WA Aug. 9, 1932. D. N. cRosTHwAlT. JR., E'r AL AUTOMATIC DI S CHARGE VALVE 3 Sheets-Sheet 3 Filed Dec. 3l, 1928 Patented Aug. 9, 1932 I UNITED gSTATES PATENT OFFICE DAVID N. CROSTHWAIT, JR., AND HARRY BRENNAN, OF MARSHALLTOWN, IOWA, ASA I SIGNORS TO C. A. DUNHAM COMPANY, 0F MARSHALLTOWN, IOWA, A CORPORATION 0F IOWA AUTOMATIC DISCHARGE 'VALVE Application led December 31, 1928. Serial No. 329,552.

This invention rela-tes to new and useful improvements in an automatic discharge valve, and more particularly to a quick-acting power-operated discharge valve especially designed for use in connection with the pumping mechanism used to maintain the sub-atmospheric pressure in a vacuum steam heating system of the type disclosed in the patent to Dunham No. 1,644,114, granted October 4, 1927.

The pumping system to which this invention is applied utilizes a hurling circuit or water in motion to produce a vacuum in the heating system and withdraw air and condcnsates therefrom. The system has an inlet which communicates with the return pipe from the heating system, and an outlet through which water is forced back to the boiler or enerator-of the heating system. The pumping system maintains a relatively low pressure or vacuum in the return pipe of the heating system so that air and condensate will be withdrawn therefrom, and a relatively high pressure is maintained in the discharge pipe so that water can be forced out against the boiler pressure. There is a cut-off valve in the discharge pipe which is normally closed, but which is opened by a float-controlled mechanism when a certain amount of water has accumulated in the pumping system so that the excess water will be forced back to the boiler. When ordinary types of valves are used at this point, diiiiculties have been encountered owing to the valves becoming leaky either from the deposits of foreign matter thereon or from the valve seats being cut owing to the very low rate of speed at which the valve is lifted, from its seat or returned thereto. Also, when foreign matter has been deposited on the valve seat, the slow motion of the valve in opening and closing does not permit suiliciently rapid acceleration of the water to enable this water to possess the energy required to remove the foreign matter.

The present invention relates to a new and improved form of cut-off valve especially designed for use in the discharge pipe of a pumping system, such as briefly outlined hereinabove, although the valve is capable of numerous other uses. The cut-off valve, is

provided with a liquid-pressure diaphragm motor Jfor quickly openmg and closing the' valve, the motor bein actuated by water at pump pressure taken from the pumping system. A pilot valve directs the motor fluid t either' side of the motor diaphragm, in order to selectivel open or close the valve, and the.

ing and closing movement, and is so designed that solids will notsettle upon or injure the valve seats.

Another object s to provide a valve and operating mechanism therefor which avoids the use of an excessive number of stuffing boxes whereby the power necessa to open and close the valves is greatly re uced.

Another object is to provide a power-operated valve, which requires comparatively little power to actuate the control mechanism therefor.

Another object is to provide an improved diaphragm operated discharge valve for a pumping system, the valve being operated by pressure fluid furnished by the pump.

Another object is to provide an improved form of pilot valve for admitting the motor fluid to the diaphragm motor which actuates the main valve.

Another object is to provide an improved form of quick-motion mechanism for actuating the pilot valve at predetermined positions of a slow moving float-actuating lever.

Another object is to provide means for positively enforcing a movement of the pilot valve in response to the movement of the float-actuated lever in case the quick-motion mechanism should fail to operate promptly.

Numerous other objects and advantages of this invention will be more apparent from the following detailed description of certain approved forms of mechanism embodying the principles-of this invention.

In the accompanying drawings:

Fig. 1 is an elevation showing the puinping mechanism with the improved discharge valve and its operating mechanism assembled therewith. y

Fig. 2 is a central vertical section, on a larger scale, through the improved valve and its operating mechanism.

Fi 3 is a vertical section through a modified form'of valve.

Fig. 4 is a vertical detail section through the pilot valve, taken substantially onythe line 4-4 of Fig. 2.

Fig. 5 is a detail elevation of the uick-motion valve-operating mechanism, ta en from the back of Fig. 2. v.

Fig. 6 is a plan view of the quick-motion mechanism. y

Referring first to Fig. 1, the pumping mechanism and exhausting system to which this invention is applied comprises a tank 1 partially filled with water, from the lower portion of which a pump 2 driven by motor 3 withdraws water through intake pipe 4 and forces this water upwardly through the discharge T 5 and jet exhauster 6 into the discharge pipe 7 leading back into the upper end of separator tank 1. This hurling water circuit produces a suction in the casing of ejector 6 which draws in water and air through pipe 8, which lmay b e the return pipe leading from a heating system. The gases and condensates drawn in from pipe 8 are carried along with the' hurling water through discharge pipe 7 and discharged into the tank 1. A one-way check-valve 9 in the pipe 8 prevents the return of any of these materials through pipe 8 tothe heating system. The gases discharged into tank 1 are vented to the atmosphere through pipe 10 provided with a T 5 of pump 2, through a one-way check-1` valve 14 back to the boiler. A cut-oil valve 15 located in discharge pipe 13 is normall closed but is opened by a float-controlled mechanism when the water level 12 intank l has risen to a predetermined point and is again closed when the excess water has been discharged from the tank. The present invention relates to an improved form of cut-off valve 15, and to the mechanism for operating this valve when the iloat in tank 1 has reached certain predetermined positions.

Referrin now to Fig.l 2, which vshwsthe v preferred; orm of valte, the'main valve cas'- ing 16 is formed with l*a central valvechamber. 17 into which leads an inlet passage 18 adapted to connect with'T 5 and an outlet passage 19 leading to the ischarge pipe 13. The inlet and dischar e passages 18 and 19 are -fitted with 4renewa lemetallic valve seats 20 and 21 having opposed seating surfaces 22 and 23 directed toward the central chamber 17. Cooperating with the valve seats 20 and 21 are a. pair of similar com sition valve disks 24rand 25. Each composition valvedisk is partiall housed within a metallic cup-shaped ho der 26, having acentral threaded stud 27 projecting throu h ank l aperture in thecenter ofthe valve dis A nut 28 threaded on stud 27 holds a washer 29 against the central portion ofthe composition valve disk. These/composition valve disks, which are-sufficiently flexible to insure an accurate fit against f the metallic valve seats, are easily renewable byv removing the nuts 2 8 and washers 29.. A supporting link 30 is pivotall-y connected' lat 'its lower end between a pair of lugs 31 projecting upwardly from the valve-supporting member 26, and` is pivotally connected at its upper end between a pair of su porting lugs 32 l projecting inwardl from t e upper portion of housing 16. This flexible supporting connection maintains the valve member in `substantial alignment withthe valve seat' but permits the necessary freedom'of movement sothat the valve1 may seat itself accurately. One end of a .toggle link 33 is pivoted at 34 between a second pair of lu s 35 projecting rearwardly from the valve holder 26. The other ends of the toggle links 33 are pivoted within a clevis 36 secured at the lower end to the vertically movable valve' stem 37. It will be apparent that when valve stem 37 is drawn upwardly, the toggle will be broken so as to draw in or toward one another the valve members 24 and 25 andopen both the inlet and dischar e passages 18 and 19 to the central valve c amber 17, whereby a free flow of liquid is permitted through the discharge valve. On the other hand, when valve stem 37 is moved downwardly, the toggle consisting of links 33 will be straightened so as to forcibly and quickly engage the respective'valve members 24 and 25 with their seats 20 and 21, thereby cutting off the valve chamber 17 from both the inlet and discharge f y passages 18 and 19.

One object of .this double valve construction is to provide a reservoir efect between the valves sothat as valve 24 approaches its seat the water is gradually restricted so that the pressure in chamber 17 is gradually reduced without the flow being entirely stopped, thereby avoiding water hammer against the oppositely closing i valve 25. A so, in case foreign matter deposits on one valve seat, the other valve still has an opportunity to come tightl to its seat and stop 5 allfiow of water throug the valve.

A removable closure 38 in the bottom of housing 16 permits access to the valve members. A cylindrical extension 39 on the top of housing 16 terminates in an outwardly projecting flange 40 to which isv secured the lower inwardly projecting flange 4l of a diaphragm casing 42. clamped at its ,outer edges between the flanges 40 and 41. The outer portion of a larger flexible diaphragm 44 is clamped between the upper side of diaphragm casing 42 and an upper downwardly dished diaphragm casing 45. The -central portion of smaller diaphragm 43 is clamped between a washer 46 mounted against a shoulder on valve stem 37 and a spacer or spool 47 positioned around stem 37 between the diaphragms 43 and 44 A pair of diaphragm plates 48 and 49 engage the opposite surfaces of the larger diaphragm 44 and are clamped against the upper end of spacer 47 by the nuts 50 threaded on the upper end of stem 37 It will now be apparent that the central portions of the two diaphragme 43 and 44, and the valve stem 37 must move up and down as a unit, that is any vertical movement of the di aphragms will -be imparted to the valve operating stem 37. A casing member 51 is supported at its upper end in an annular recess 52 formed in the neck portion 39 of housing 16, and the lower portion 53 of this casing 51 fits loosely about the valve stem 37 so as to form a ide for this stem. The casing 51 forms a partially closed chamber 54 beneath the diaphragm 43 so as to protect this diaphragm from the flowing aet1on of the water through the valve chamber 17.

A substantially closed pressure chamber 55 is formed within upper diaphragm casing 45 above the main diaphragm 44, the only communication with this chamber being through inlet and outlet passage 56. In a similar manner, a closed chamber 58 is formed between the diaphragms 43 and 44, a single passage 59 communicating with this chamber. As fluid under pressure is alternatively forced into one chamber 55 or 58 and discharged from the other, the valve stem 37 will be forced downwardly or upwardly so as to close or open the valves 24 and 25.

The pilot valve 6() comprises a casing secured by screw bolts 61 to the diaphragm casings 42 and 45. The pilot valve is formed with a central liquid receiving chamber 62, and a pair of similar upper and lower liquid chambers 63 and 64 which respectively communicate through passages 65 and 66 with the passages 56 and 59 leading to the diaphragm operating pressure chambers 55 and 58. A supply pipe 67 leads from the pump A flexible diaphragm 43 is.

`jet exhauster 6 or to the discharge pipe 7 discharge l 5 to the central ressure chamber 62 of the pilot valve where y water under pump pressure is constantly supplied to this chamber 62. A branch pipe 68 may lead from the conduit 67 to apressu're indicator 69.

Valve passages 70 and 71 lead res ectively from inlet chamber 62 to the two ischarge chambers 63 and 64,. and a'v valve stem 73 guided through these passages carries a valve head 74 which is vertically movable within the chamber '62. Valve head 74 is formed with an upper valve seat 75 adapted to cooperate with an upperfixed valve seat 76 to close the valve passage 70, and is also formed with a lower Valve seat 77 adapted to cooperate with the lower fixed valve seat 78 to close the lower valve passage 71. The upper reduced portion of valve stem 73 projects upwardly through a bonnet 79 in which is housed a packing 8O pressed downwardly and against the valve stem by means of the gland 81 and spring 82. This packing assembly serves to prevent the liquid under pressure from passing out around the vertically reciprocable valve stem 73. 9 Referring now more particularly to Fi 4,- it will be noted that a constantly opennut smaller restricted discharge passage 83 leads from the upper chamber 63 to a liquid discharge chamber 84. Similarly a restricted 95 discharge passage 85 leads from the lower chamber 64 to the chamber 84. A liquid discharge pipe 86 leads from chamber 84 to the above the exhauster.

With the valve stem 73 in its lowered position, as shown in Figs. 2 and 4, the lower valve passage 71 will be closed, but the upper passage 70 will be open so that liquid under pressure is forced from the pump through conduit 67 to the receiving chamber 62 of the pilot valve, and thence through passage 70, chamber 63 and passages 65 and 56 to the upper pressure chamber 55 above diaphragm 44. At the same time the pressure in chamber 58 beneath diaphragm 44 will be partially dissipated through the passage 59, chamber 64, discharge passage 85 and thence through chamber 84 and conduit 86 to the discharge side of the pumping system. Consequently the excess pressure on the upper side of diaphragm 44 will force the valve stem 37 downwardly and quickly close the valves 24 and 25 so as to cut ofi' the flow of liquid through the discharge valve and pipe 13. There is also a constant flow of this liquid under pressure through outlet passage 83 from the upper chamber 63, but since the inlet passage 70 is considerably larger than the restricted outlet 83 a sufficient pressure will be built up in chamber 55 to operate the diaphragms and hence close the valves. On the other hand, if valve73 is lifted so as to close valve passage 70 'and o en valve passage 71, the

pressure in lower iaphragm chamber 58 will 130 lbe raised and the pressure in upper chamber 55 lowered so that the valve 'stem 37 will be lifted and the main valves 24 and 25 will be opened.

It will be apparent that the discharge passages 83 and 85 could be controlled by pilot valves concurrently with the opening and closing of the main pilot valves which control the passages and 7l. However, it is desirable for some reasons to utilize the constantly open discharge passages 83 and 85 although this results in a slight but continuous loss of pressure. If any leakage should occur through either of the pilot valves, this leakage will notresult in the actuation ofthe main diaphragna-operated valves unless the leakage should exceed the constant loss of liquid through the discharge passage 83 or S5. Consequently, even though the pilot valves should not properly seat at any time, any small amount of leakage, less than the outflow through the restricted passages 83 and 85, will not result in any undesired actuation of the main valves.

A yoke 87 supported centrally upon the bonnet 79 has a pair'of oppositely upwardly extending arms 88 and 89. The upper end of valve stem 73 is loosely pivoted on pin 90 mounted in the forked intermediate portion 91 of a valve. lever 92 fulcrumed at one end on pin 93 in the yoke 94 at the upper end of arm 88. A roller 95 is freely pivoted on pin 96 in the fork 91 of lever 92. An operating lever 97 is rigidly secured at 98 to one arm 99 of rocker member 100 pivoted at 101 in the yoke 102 at the upper end of arm 89. The other arm of rocker 100 has the form of an enlarged head 103 in which the upper-end of a The free end of lever 92 projects beyond theintermediate fork 91, as a side arm 111, the free end of which extends loosely between a pair of fingers 112 and 113 projecting later-` ally from the arm 99 of rocker 100.

The other end ofv lever 97 is connected through a link 114 with a crank arm 115 secured to the outer end of a rock shaft 116 journaled in the upper portion of tank 1. A float 117 mounted in the tank 1 is connected by crank arm 118 with the rock shaft 116.

It will now be'apparent that as the liquid accummulates in tank 1, the float 117 will be elevated thereby through the lever and link connections justdescribed raising the longer arm of lever 97 (including rocker 100) and lowering the shorterarm thereof so as to force the cam plate 104 downwardly against the roller 95. The cam plate will be forced `Laramie .rearwardly compressing the spring 106 until the neat eak 110 of the cam surfaces passes bethe center of roller 95, whereupon spring 106 will suddenly expand forcing the' valve passage-71 so `that the `actuating pressure liquid will be forced into the lower diaphragm chamber 58 and discharged from the upper chamber 55, whereupon valve stem 37 will be raised and the main valves 24 and 25 opened. The pump 2 will now force liquid from tank 1 out through discharge pipe 13 until the quantity of liquid in tank 1 has been so reduced that the float 117 will fall sufliciently to lower the long arm of lever 97 and raise the short arm until the peak 110 of the cam surfaces has passed above the center of roller 95, whereupon spring 106 will again expand and suddenly force the roller 95 downwardly along cam surface 109 so as to return the valve stem 73 and pilot valves carried thereby to the positions shown in the drawings. The motor liquid will now again be directed to the upper diaphragm chamber 55 and discharged from the lower chamber 58 so that the main valves 24`and 25 will be quickly and positively closed. This will cut olf the discharge of liquid through pipe 13 to the -boiler and all of the liquid withdrawn from tank 1 by pump 3 will again be forced through the exhauster 6 and back to the tank 1 (with the exception of the small stream of liquid that is constantly forced through the pipe 67 to the pilot valves and thence through discharge pipe 86 to the hurling circuit discharge pipe 7.)

In normal operation the arm 111 of lever 92 will never contact with either of the fingers 112 or 113 on the rocker 100. However, in case vthe cam-actuated roller of the quickmotion mechanism should stick or fail to operatef, further .movement of float-actuated lever 97 and rocker 100 will cause one of the fingers 112 or 113 (according to the direction of movement) to engage the arm 111 and positively enforce the shifting of valve stem 73.

In the modification shown in Fig. 3, a sin- K gle main valve 119 is used instead of the pair of opposed valves 24 and 25 as described in connection with Fig. 2. The composition valve member 119 engages with a valve seat 120 fixed within the horizontal web 121 which separatesinlet passage 122 from outlet passage 123. B v arranging the valve at this angle to the flow of water, it gives the least obstruction to the flow and does not have a tendency to produce water hammer to the eX- tent that would result from the closing of a vertically positioned valve having its plane at right angles to the liquid flow. The' valve holder 124 is swiveled on the head 125 on the lower end of valve stem 37 and is held in 4place by nut 126. The composition valve member 119 is held in place Within its seat in the holder 124: by means of the winged nut 127 and lock nut 128 which are threaded on stud 129 projecting downwardly from the holder. The wings of the nut 127 engage within the passage 129 through valve seat 120 and thus serve to guide the valve member in its vertical movements. The mechanism for operating the valve stem 37 is the same as that described in connection with Figs. 2 and 4.

The valves in both forms of this apparatus are so mounted that they can seat accurately, and the wearing parts are renewable. A power operated mechanism has been provided which opens and closes the valves quickly and positively whereby cutting action of the water is avoided and suiiiciently rapid acceleration of the water is permitted to enable this water to remove any foreign matter that may lodge on the valves or valve seats. Although sufiicient power is derived from the pump to operate the main valves forcibly and positively, very little power is required to operate the pilot valves, and a quick-motion mechanism is provided whereby the float may rise or fall slowly and steadily and asudden snapaction will be imparted to the pilot valves at certain predetermined positions of the float. While this new discharge valve and its operating mechanism have been designed especially for use in the pumping mechanism here disclosed, it will be apparent that this valve assembly may be used in other forms of apparatus and such uses and modifications are contemplated as being within the scope of the claims which follow.

We claim:

1. An automatically operated cut-ofi:l valve comprising a valve casing having an inlet and an outlet, a valve member adapted to control communication between the inlet and outlet, a stem projecting from the casing and operatively connected with the valve member at its inner end, a. differential pressure motor comprising a casing, a flexible diaphragm dividing the casing into separate chambers, the outer end of the stem being connected with the diaphragm, and a,pilot valve comprising a casing housing, an inlet chamber connected with a source of fluid under pressure, there being separate passages leading from the inlet chamber to the diaphragm chambers, a valve stem, a pair of valves mounted on the stem and adapted to alternatively close the passages, an operating lever pivotally mounted on the pilot valve casing, a lever pivote'd at one end on the casing and intermediately Connected with the valve stem, a roller mounted 0n the lever, a cam movably mounted on the operating lever, and a spring adapted to yieldably force the cam into the path of the roller.

2. An automatically operated cut-off valve comprising a valve casing having an inlet and an outlet, a vali'e member adapted to control communication between the inlet and outlet, a stem projecting from the casing and operatively connected with the valve member at its inner end, a differential pressure motor comprising a casing, a flexible diaphragm dividing the casing into separate chambers, the outer end of the stem being connected with the diaphragm, and a pilot valve comprising a casing formed with an inlet chamber and a pair of discharge chambers, valve-passages connecting the inlet chamber with the discharge chambers, a valve stem, a pair of pilot valves mounted on this stem and adapted to alternatively close the valve passages, a passage leading from each discharge chamber to* one of the diaphragm chambers, a restricted outlet for each discharge chamber, connections for supplying a fluid under pressure to the inlet chamber, and means for operating the valve stem.

3. A quick-acting pilot valve comprising a valve casing housing an inlet chamber, a pair of outlet chambers, a valve-stem reciprocable through the casing, a pair of valve members fixed to said stem and adapted to alternatively Open one and close the `other of two passages connecting the inlet chamber with the respective outlet chambers, a lever pivotcd at one end to the casing and intermediately pivotcd to the outer end of the stem, a roller mounted on the lever, an actuating lever intermediately fulcrumed on the casing, a cam movably mounted on the actuating lever, and

a spring carried by the actuating lever and in the casing, a lever pivotcd at one end to l the casing and intermediately connected to the outer end of the stem, a roller on the free end of the lever, an actuating lever intermedi atcly fulcrumed on the casing, a cam movably mounted 0n the actuating lever, and a spring carried bythe actuating lever and urgino' the cam yieldingly into the path of the roller. y

5s A quick-acting pilot valve comprising a valve casing, a 'valve-stem reciprocable through the casing, Avalves on the stem within the casing, a valve lever pivotcd at one end on the casing and intermediately connected to the outwardly extending portion of the valve stem, a roller mounted o'n the lever, an

in response .to movement ofrthe. actuating' lever in casethe cam-actuated roller'should fail to move the valve lever. c f

6.,'A quickacting pilot -valvecomprising c a valve casing a valve-stem reciprocable through the casing, valves on the stem within the casing, a valve lever pivoted at one end on the casing and intermediately connected to the outwardl' extendin portion of the valve stem, a rol er mounte on the lever, an actuating lever fulcrumed on the casing, a cam movably mounted in one arm of the actuating Iever,a spring carried by the actuating lever andurging the vcam yieldingly into the path of the roller, there being a pair ,of spaced fingers projecting laterally from one arm of the actuating lever, the free end portion of the valve lever projecting between Y.these fingers but normally' out of vengagement therewith. l'

` 7. A pilot valve comprising a, casing a' suction chamber, a 'restricted outletfrom each outlet chamber to the suction chamber, a suction pipe connected with the suction chamber, connections for supplyino' a fluid under ressure to the inlet` cham `r,-"-and 70 means or operating the valve: stem ofjthe pilot valve. i a' DAVID N. CROSTHWAIT, JR. HARRY BRENNAN.

soi

las

' I formed with an inlet chamber and a pair of outlet chambers, valve passages connecting the inletv chamber with the outlet chambers, g5 a valve stem, a pair of valves mounted on the stem and adapted to alternatively close the valve passages, a main outlet passage leading from each Voutlet chamber, a restricted outlet passage leading from each outlet chamber, an connections for supplying a fluid under pres- Sure t0 the inlet chamber, and means for operating the valve stem. 8. A pilot valve comprising a casing formed with an inlet chamber and a pair of bals' outlet chambers, valve passages connecting the inlet chamber with the outlet chambers, a valve stem,- ya pair of valves mounted on the ystem and-adapted to alternatively close the valve passages, a main outlet passage leading o from each outlet chamber, a suction chamber, a restricted passage between each 'outlet chamber and the suction chamber, a suction pipe connected with the suction chamber,

i connections for supplying a fluid under pressure to the inlet chamber, and means for operating the valve. stem.

9. An automatically operated cut-oif valve comprising a valve casing having'an inlet and an outlet, a valve member adapted to control communication between the inlet and outlet, a stem projecting from the casing and operatively lconnected with the valve member at its inner end, a differential ressure motor comprising a casing, aexi le diaphragm dividing the casing into separate pressure chambers, the stem being connected with the diaphra m, and a pilot valve comprising a casing ormed with an inlet cham- -ber and a pair of outlet chambers, valve passages connecting the inlet chamber with the outlet chambers a valve stem, a pair of valves 0n the stem adapted to alternatively close the valve passages, a passage leading from each outlet chamber to one of the pressure chambers of the diierential pressure motor, i

Images