US2356970A

US2356970A - Pilot means for liquid level controls and the like

Info

Publication number: US2356970A
Application number: US432380A
Authority: US
Inventors: Glenn F Brockett
Original assignee: Fisher Governor Co
Current assignee: Fisher Governor Co
Priority date: 1942-02-26
Filing date: 1942-02-26
Publication date: 1944-08-29
Anticipated expiration: 1961-08-29

Description

1944- G. F. BROCKETT 2,356,970

PILOT MEANS FOR LIQUID LEVEL CONTROLS AND THE LIKE Filed Feb. 26, 1942 3 Sheets-Sheet 1 i 69 35 4a 39 44 6a a G e I W A Aug. 29, 1944. G. F. BROCKETT PILOT MEANS FOR LIQUID LEVEL CONTROLS AND THE LIKE Filed Feb. -26, 1942 5 Sheets-Sheet 2 w M m 7 9 WM 0 0 i aMi W i r w Aug. 29, 1944. G. F. BROCKETT PILOT MEANS FOR LIQUID LEVEL CONTROLS AND THE LIKE 3 Sheets-sheaf 3 Filed Feb. 26, 1942 Patented Aug. 29, 1944 UNITED STATES PATENT OFFICE PILOT MEANS FOR LIQUID LEVEL QONTROLS AND THE LIKE Glenn F. Brockett, Marshalitown, Iowa, assignor to Fisher Governor Company, Marshalltown, Iowa, a corporation of Iowa Application February 26, 1942, Serial No. 432,380 Claims. (curl-c8) operation.

Another object of this invention is to provide a,

pilot means of the character referred to thatis readily adjustable for an extensive range of uses or applications and that is devoid of levers, pivots and other parts likely to produce friction to interfere with the smooth dependable operation.

Another object of this invention is to provide a pilot means of the character mentioned that is entirely pneumatic and adapted for control or operation by air-under pressure or any other suitable non-corrosive gas under pressure.

Another object of this invention is to provide a control of the character referred to embodying a system for carrying the auxiliary fluid pressure for the operation ofthe motor valve which governs the fluid under control, a pilot controlling the pressure of the auxiliary fluid as delivered to the motor valve and having a continuously operative bleeder under the control of a selected level responsive means which operates to govern or throttle the discharge from said bleeder and thus control the pilot, and a novel compensating means associated withthe bleeder. The compensating means is responsive to the pressure of the auxiliary operating fluid supplied to the motor valve and upon an increase in this pressure, resulting from a throttling of the bleeder, the compensating means produces relative movement between the bleeder orifice and the flapper or member controlling the same to counteract or partially compensate for the restriction or throttling of the bleeder and thus assure a smooth operation of the motor valve without a loss in the sensitivity of the apparatus and providing for the employment of a throttling range adjustment to be later referred to.

Another object of this invention is to provide a pilot mechanism of the character referred to embodying a simple readily manipulated means for adjusting the "level" setting, that is, for adlusting the pilot to operate at any selected or required level or level range of the fluid being governed, without resorting to the necessity of disturbing or adjusting the liquid level responsive unit.

Another object of this invention is to provide a pilot means of the character mentioned that I sive throughout any portion of a wide range of level.

may be employed either as a direct action control or as a reversed action control, depending upon the conditions of operation and the installation. In some installations it may be desired to open the motor, valve upon a rise of the liquid level, while in other cases it may be desired to close the motor valve upon a rise of the liquid structed to open or to close upon an increase in the pressure on its diaphragm and there may be other reasons for reversing the action of the pilot. The pilot maybe easily and quickly reversed by merely reversing the position of the Bourdon tube compensating means, an operation merely necessitating the removal and re-installation of a few screws.

A further and important object of this invention is to provide apilot mechanism of the class referred to embodying a throttle range adjustment providing for movement of the motor valve through its entire stroke or any portion thereof for any given or selected level change, throughout a wide range of level variation. The throttling range adjustment of the invention provides for a full stroking of the motor valve through a wide or narrow level variation while maintaining the sensitivity and smoothness of operation of the apparatus. The throttling range adjustment is readily adjustable to control the ratio between the auxiliary pressure being bled oif at the throttling range adjustment and the auxiliary pressure being supplied to the compensating Bourdon tube, thus producing the throttling range adjustment without decreasing the sensitivity or accuracy of the pilot means at any setting of the throttling range adjustment.

The various objects and features of my invention will be fully understood from the following detailed description of a typical preferred form and application of my invention, throughout which description reference is made to the accompanying drawings, in which:

Fig. 1 is a diagrammatic view of the pilot means of the invention associated with its motor valve with certain of the diagrammatically illustrated parts in cross section. Fig. 2 is an elevational view illustrating the manner in which the pilot mechanism may be associated with a liquid level responsive means. Fig. 3 is an enlarged front elevation of the pilot mechanism with the door of the case in the open position. Fig. 4 is an enlarged fragmentary detailed sectional view of the throttling range adjustment means taken as indicated by line H on Fig. 3. Fig. 5 is an enlarged fragmentary detailed sectional view of Further, the motor valve may be conthe compensating means and the level adjusting means taken as indicated by line l---! on Fig. 3. Fig. 6 is an enlarged vertical detailed sectional view taken as indicated by line 4-4 on Fig. 5. Fig. 'l is an enlarged vertical detailed sectional view taken as indicated by line iv-1 on Fig. 5 and Fig. 8 is an enlarged perspective view of the adiustable stop of the liquid level adjustment.

The control or piloti oa. the present invention '-may be employed in'connection with apparatus varying considerably in character and has many applications. In the drawings I have shown the pilot associated with a liquid level responsive means iii of the general character described and claimed in my co-pending application Serial No. 430,161, flled February 9, 1942. The level responsive means i4 is connected in a level equalizing pipe Ii which has communication with a vessel V at vertically spaced points. This type of level responsive means includes a casing i2 containing a float l2 responsive to the liquid level and operatively connected with a torsion tube i4 to twist the same. A shaft i4 is connected to the torsion tube i4 and extends from the casing of the means ill to operate the control or pilot. The pilot is preferably, though not necessarily, arranged at the outer end of the casing arm i5 and preferably includes a housing or case it. The case it of the pilot has a vertically-disposed base plate il secured to the outer end of the easing arm is and further includes a cover is hinged to the plate ii. The cover i4 is cupped or shaped to receive the various elements of the control which are mounted on the plate I! and has suitable sights or windows is to make the dials and other parts of the pilot readily visible. Fig. 3 of the drawings shows the cover in the open position, it being understood that the cover is normally closed and held in the closed position by a latch or screw 24.

In' the particular application or the invention illustrated the pilot serves to operate or control a motor valve 2i. It may be assumed that the valve 2! is connected in a pipe 22 for conducting fluid to the vessel v, it being understood that in 45 many cases the valve under the control of the pilot may serve to govern a pipe line carrying fluid from the vessel. The valve 2i embodies a motor diaphragm means 22 and a spring 22 for effecting opening and closing oi. its inner valve. It is to be understood that the valve 2i may be either opened or closed by the auxiliary operating fluid pressure supplied to its diaphragm means 22".

The automatic pilot mechanism of the present invention may be said to comprise, generally, a relay 24 interposed in the auxiliary fluid pressure line 24, bleeding means 24 for the relay 24 controlled by the shaft is to govern the action of the motor valve 2i, compensating means 21 associated with the bleeding means 26, and throttling range adjustment means 24.

The relay 24 is responsive to the rate of discharge of the auxiliary operating pressure from the bleeding means 24 and serves to govern the magnitude of the auxiliary operating pressure supplied to the motor valve 2|. Thus, the motor valve 2| is responsive to the action of the shaft it through the medium oi! the relay 24 and the bleeding means 24. The relay 24 is mounted on the supporting plate I2 and includes a body made up of an inner section 22, an intermediate section 24 and an outer section 2i. The

sections

29, 20 and 2| are shaped to constitute a hollow or chamtheir peripheral edge portions secured between theopposing laces oi the

sections

22, 24 and 21 and extend across the interior or the assembly to partition the same into inner, intermediate and

outer chambers

24, 24 and 24, respectively. The outer diaphragm 22 is of larger eflective diameter than the inner diaphragm 22 and may be termed the primary diaphragm. while the inner diaphragm 22 may be termed the secondary diaphragm. The

diaphragms

22 and 22 are connected or associated to form a differential diaphragm element. A floating block 21. is engaged against or secured to the opposing faces 0! the

diaphragms

22 and 22 and has a stem 24 passing through a central opening in the diaphragm 22. A nut 24 is threaded on the stem 24 and engages against the under side of the diaphragm 22 to positively secure the block to the diaphragm. A spring 40 is arranged under compression between the under sideoi the diaphragm 22 and the bottom wallet the chamber 24 to counter balance the weight of the block 21 and to urge the

diaphragms

22 and 22 outwardly.

The auxiliary operating fluid pressure, which may be airunder pressure or any other selected non-corrosive gas under pressure, is delivered to 'a distribution opening 4i in the inner section 22 of the relay body. The auxiliary operating pressure line 24 may extend directly to the opening 4i and may be equi ped with a suitable pressure gauge 42. A port lads from the opening 4i to the inner diaphragm chamber 24 and ports and a conduit 44 conduct the auxiliary operating pressure from the distribution opening 4i to the outer diaphragm chamber 24. An oriflce fltting 45 is provided in the port and conduit system 44 to reduce or bean down the fluid flow and to create a pressure drop in'the fluid delivered to the outer diaphragm chamber 24.

, 40 A valve 44 governs the port 42 to control the delivery of the auxiliary operating fluid pressure to the inner diaphragm chamber 24. The valve 46 is a tree floating valve urged toward the closed position by a spring 41. The valve 44 has a second head engaged in or adapted to close a, port 48 in the block 21. The engagement of the block 21 with the valve 44 causes the valve to move downwardly or open, upon inward movement of the

diaphragms

22 and 22, and upon outward movement 0! the diaphragms the spring 41 moves the valve 46 to the closed position. The port 44 leads through the block 21 to the intermediate chamber 24 and the chamber 24 is vented to the atmosphere at 42. The valve 44 normally closes the port 42 during the operation of the pilot but in the event the pressure in the chamber 24 becomes excessive the

diaphragms

22 and 22 move outwardly away from the valve 44 so that the port4sisopentopermit thebleedingottheexcess pressure to the atmosphere.

The valve 44 is normally cracked" or slightly open during the operation oi the pilot to put the inner diaphragm chamber 24 in communication with the source of auxiliary operating pressure. Thus, the auxiliary operating pressure is supplied to both

diaphragm chambers

24 and 26. The bleeding means 24 bleeds oil pressure from the outer chamber 24, as will be later described, providing for a diilerential in pressures in the

chambers

24 and 24 but this difl'erential in pressure is compensated for, at least to some extent, by the difl'erential in diaphragm dismeters so that during normal operation the valve 46 is only slightly cracked to put the chamber bered assembly and

diaphragms

22 and 22 have 7 24 in partial communication with the procure supply opening 4|. A pipe or conduit 56 leads from the inner diaphragm chamber 64 to the motor diaphragm means 22 of the motor valve 2|. A suitable pressure gauge 6i may be provided on the conduit 50. It is to be understood that the mounting plate II of the pilot casing I6 is ported and has ports and passageways forming parts of the

conduits

26 and 56.

The bleeding means 26 serves to vent or bleed auxiliary operating pressure from the primary diaphragm chamber 66 and this venting action is under the control of the level responsive shaft l and the compensating means 21 so that the action of the relay 24 is dependent upon movement of the shaft l5 and the setting or adjustment of the throttle range adjustment 26 which controls the compensating means 21. The bleeding means 26 comprises a tube or conduit 52 leading from the outer diaphragm chamber 36. The conduit 52 extends to a mounting base 56 suitably secured to the casing plate i1. The conduit 52 communicates with a port 54 in the base 53 and the port 64 extends outwardly or perpendicularly to the face of the base. A block 55 is detachably mounted on the outer or forward end of the base 53. In accordance with the invention the block 55 is secured to the base 56 by screws 56 engaged in symmetrically disposed openings 51 in the base and block. A port 56 extends longitudinally through the block 55 and its inner end has communication with the port 54. The outer end of the port 58 is closed by a plate 65 held in place by the screws 56. Suitable gaskets are provided between the opposing faces of the base 53 and block 55 and between the outer end of the block and the plate 65. The block 55 is provided with a lateral port 59 leading from the longitudinal port 56.

A tube 66 is secured to the block 55 and extends outwardly or laterally from the port 56. The end of the tube 60 may be anchored in the port 59 and the tube may be welded to the block as illustrated in Fig. 7. The tube 66 has the shape or curvature of a Bourdon type for the purpose to be later described. A block or head 6| occurs at the outer end of the tube 66 and has a passage or opening 62 which receives or passes the end portion of the tube 66. An orifice cap 63 is threaded on the outer portion of the head 6|. A reduced discharge orifice 64 occurs in the outer wall of the cap 66 for the discharge of the auxiliary operating pressure. The bleeding means 26, as thus far described, is such that the auxiliary operating fluid pressure in the chamber 26 would bleed away to the atmosphere leaving little more than atmospheric pressure in the chamber 26 in the event the orifice 64 is uncontrolled or fully open.

The invention provides novel means operable by the shaft l5 for controlling the discharge of the auxiliary operating fiuid pressure from the nozzle orifice 64 to thereby govern the relay 24. This means comprises a clamp or frame 66 secured to the shaft l5 to turn therewith. The frame 66 has a horizontal opening 61 passing the shaft l5 and a vertical opening 66 intersecting the opening 61. A clamp screw 66 is arranged in the opening 66 and has a horizontal opening 16 receiving or passing the shaft ii. A nut 1| is threaded on the upper end of the screw 66 and is engaged with the upper end of the frame 66 to draw the screw upwardly and thus tightly clamp the frame on the shaft ii. A horizontal groove 1| is formed in the upper side of the frame 66 in transverse relation to the shaft i5 and the shaft passes through this groove.

A flapper or blade 12 is pivoted on the shaft i6 within the groove 1| and projects outwardly beyond the frame 66. The notch or groove 1| serves to guide the blade 12 and is such that the blade may be swung through an arc of more than to project beyond either side of the frame as desired. A weight 14 of the desired magnitude is fixed on the blade 12 to urge the same downwardly. The blade has flat sides and is adapted to oppose the orifice 64 of the nozzle 63 to close or substantially close the orifice to control the discharge of the auxiliary operating pressure therefrom.

The invention further includes a novel adjustable stop means for stopping or positioning the blade 12 with respect to the frame 66 and shaft II. It will be seen that by adjusting the position of the blade 12 with relation to the shaft ii that a level adjustment may be made. Such a level adjustment will provide for operation of the pilot at any selected or required liquid level of the vessel V. This level adjust-ment at the pilot eliminates the necessity of adjusting the shaft i5 or other elements of the means In and all parts of the liquid level responsive means l0 may have permanent settings in the sealed casing I2.

The level adjusting means includes a stop or contactor 15 pivoted on the clamp or frame 66 and is best illustrated in Fig. 8. The contactor has a pair of wings 16 disposed at opposite sides of the frame 66 and a depending rear part 11 spaced behind a vertical depending flange 16 of the frame 66. Horizontal trunnions or pivot pins 19 project from opposite sides of the frame 66 and are received in openings 66 in the upper portions of the wings 16 to support the contactor 15 for pivotal movement on the frame. Screw means is provided for swinging or adjusting the contactor 15 with respect to the frame 66. This means includes a screw 6| having a polygonal or flat sided part 62 engaging in a correspondingly shaped opening 63 in the rear part 11 of the contactor 15. A head 64 on the screw 6| engages against the rear face of the contactor part 11. The screw 6| passes forwardly through an opening 66 in the flange 16 and an adjusting knob 66 is fixed on the forward end of the screw.

, The knob 66 is formed to react or engage against the flange 16. A spring 61 surrounds the screw 6| and is engaged under compression between the contactor part 11 and the frame flange 16. It will be seen that by rotating the knob 66 the contactor 15 may be pivoted or swung forwardly or rearwardly depending upon the direction of rotation.

The wings 16 of the contactor 15 have upwardly projecting tips or lugs 66. These lugs 66 occur at the opposite ends of the groove 1| so that either one or the other is engaged by the blade 12. The blade 12 may be swung through an arc of 180 or more to project from either side of the frame 66 for the direct action or reversed action of the pilot as will later appear, and when in either of these positions the blade cooperates with a lug 66. By turning the knob 66- the engagement of the lug 66 with the blade 12 causes the blade to be pivoted upwardly or downwardly relative to the shaft l5 to effect the level adjustment. A calibrated dial 66 may be provided on the front of the flange 16 to indicate the setting of the blade 12 and, therefore, the level" adjustment of thepilot. The knob 66 may be The compensating means 21 is under the control of the throttling range adjustment means 28 and, if desired, may be considered as an element of the means 28. The compensating means 21 serves to move the nozzle 63 with respect to the blade 12 in response to variations in the pressure of the auxiliary operating medium as supplied to the motor valve 2! to increase or decrease the amount of travel of the valve 2i per unit 01' movement of the float 13 or shaft II. The means 21 includes a Bourdon tube, or the equivalent, which I will here term the compensator tube" 90 associated with the tube ill to var the position of the nozzle 63 with respect to the blade 12 in response to the conditions 01' pressure in the auxiliary operating line 80 of the motor valve 2|. The compensator tube ll is secured to the block 55 and extends outwardly therefrom to carry the nozzle head BI and is in surrounding or enclosing relation to the tube 60 throughout the major portion of the tube 60. The compensator tube 90 surrounds the tube II with ample clearance, leaving a substantial space to receive the fluid pressure. The inner end oi the compensator tube 90 is anchored and sealed to th block 55 as by welding 9| and the head 6i may be fixed and sealed on the outer end of the tube ll by welding 82. The head 6| serves to close the outer end of the compensator tube so. The tube II is formed of suitable thin walled flexible and resilient stock to flex in response to variations in the internal pressure.

The block 55 has an opening or port 03 spaced from and complementary to the above described port 58. A lateral port 84 connects the port 23 with the inner end of the tube 90. The inner end of the port 93 communicates with a port 9| in the mounting base 52. A conduit 96 is suitably connected with the mounting block '53 to communicate with the port 95 and extends to the throttling range adjustment means 28, which in turn controls the communication of the conduit 88 with the auxiliary operating pressure line SI of the motor valve 2|. When the shaft [5 is moved by the fluid level responsive means II to cause movement of the blade 12 toward the nozzle 63 the blade limits or further restricts the orifice 64 producing a back pressure in the tube 60, conduit l2 and the chamber 36. Increased pressure in the chamber 36 results in opening or further opening of the valve 46 and there is an increase in the auxiliary operating pressure applied to the diaphragm means 22 of the pilot valve 2|. Increase in the pressure on the fluid in the conduit I0 is accompanied by an increase in the pressure within the compensator tube 90 with the result that the tube tends to straighten out and thus move the nozzle 63 away from the blade 12. This movement of the nozzle terminates or reduces the effect of the initial movement of the blade 12 and the stroke or movement of the diaphragm means 22 of the motor valve 2| is reduced in proportion.

As mentioned above, the pilot may be employed for direct action control or for reversed action control. The

ports

54 and 93 which respectively supply pressure to the tubes 60 and ll are symmetrically disposed with relation to the screw holes 51 and both pass completely through the block 55, the outer ends of the ports being closed by the plate 65. With the

tubes

60 and 90 in the position illustrated in Fig. 1 it may be assumed that the apparatus is employed for direct action control. In the event that it is desired to use the pilot for reversed action control the screws ll are removed and the block II and plate II are detached. The block ll carrying the tubes II and II is thenturned over or moved through and re-engaged against the base II. The plate II is applied to its outer end and the plate and block are secured to the base II by the screws II. This results in the tubes ill and Ill being inthe position shown in Figs. 3 and 7. When the block ll is inverted or turned side for side the ends of the ports I8 and I! are merely reversed or turned end for end and because oi the symmetric disposition of the screw holes II the port ll remains in communication with the port 84 and the port I! remains in communication with the port ll so that the actions of the nozzle 0 and compensator tube II are the same as before. When the tubes are reversed as just described the flapper or blade 12 is merely swung over to bring it into position where its face opposes the nozzle oriflce OI. In this connection it is to be observed that there is s contactor lug I. for engaging the blade II with the blade in either position.

The throttle range adjustment means 28 is interposed between the compensator tube II and the line ll carrying the auxiliary operating fluid pressure to the motor valve 2|. The throttle range adjustment means 28 is operable to regulate or vary the ratio between the fluid pressure in the conduit II and the compensator tube ll. The line or conduit 28 leading to the compensator tube ll extends to a block or body 01 having a stem threaded in an opening II in the mounting plate H. .A port OI extends through aparto! theplate i1 and joins the opening ll and a tube ill leads from the port ll to the motor valve line I. The

blockorbody l'lhasahorizontal D rt Ill extending longitudinally through its stem and communicating with the port 9!. A horizontal opening "2 or increased diameter continues through the body II from the port III. A lateral port Ill joins the opening 2 and the line or conduit 00 from the compensator tube I extends to this port III. A second lateral port Ill is formed in the body" andjoinstheopening lllatspoint spaced outwardly from the port I". The port I is in thenatureoi'ableedportorventport. An adjusting screw III is threaded in the outer portion of the opening I22 and has a readily manipulable adjusting knob ill. The screw III is proportioned so that it does not close the bleed port I. 'A tubular bleed orifice fitting III is threaded in the opening I02 to occupy a position between the ports III and ill and is flxedinplsee by a set screw ill.

The throttle range adjustment means iurther includes a valve Ill for simultaneously controlling the port ill and the bleed oriiice ill. The

valve Ill may be in the nature of a double endedneedle valve and is positioned in the opening I02 to have one end project into and control the port ill and the other end control the bleed orifice ii". A stem III is provided on the outer end of the valve I II and passes through the oriflce fitting ill! with clearance to leave a passage for the fluid. The outer end of the stem III is engaged by the inner end of the screw I". It will be seen that by threading the screw ill inwardly the valve I'll moves inwardly to further close the port I M and to move away from the orifice fltting I01 and thus diminish the flow of the auxiliary operating fluid pressure to the compensator omduit 06, while at the same time increasing the bleeding of the same pressure from the conduit or the conduit supply. A spring 2 is arranged under compression between a shoulder on the double ended valve H and the inner wall 01 the Opening I02 to urge the valve outwardly. When a the screw I05 is threaded outwardly the spring 86 is flxed to the shaft and upon turning of the shaft the weighted blade 12 likewise moves. In the event the blade 12 is moved toward the nozzle 63 the discharge of the gas from the nozzle is restricted or reduced thus producing a back pressure in the outer diaphragm chamber 36 of the relay 24. An increase of pressure in the chamber 36 results in rearward movement of the valve 46 so that the delivery of the auxiliary operating pressure to the conduit 50 is increased. An increase in the pressure of the line 50 results in operation of the valve 2| in a manner to correct or compensate for the liquid level change in the vessel V.

An increase in the pressure in the line 50 is communicated to the interior of the compensator tube 90 through the medium 01' the throttling range adjustment means 28. An increase of the pressure in the compensator tube 90 tends to straighten the tube 90 so that the nozzle 63 is moved away from the blade 12. This movement of the nozzle from the blade 12 results in a change in the diaphragm motor operating pressure of lesser magnitude for given level change than would have occurred if the compensator tube was not present. Accordingly, by adjusting the magnitude of the pressure change in the compensator tube 90 in proportion to the pressure change in the motor valve pressure line 30 it is possible to adjust the motor valve travel for any given unit of liquid level change in the vessel V. This throttling range adjustment is effected by merely turning the knob I06. Ii the knob "I8 is turned to move the valve H0 inwardly the port Hll is further closed and the choke llll is further opened with the result that the pressure in the compensator tube 90 is increased to a lesser extent when a given pressure'is built up in the motor valve operating line 50. The result of this is that the compensator tube 90 will have a shorter motion in response to the internal pressure change and there will be a proportionately greater increase in the operating fluid pressure applied to the motor valve 2|, thus giving the motor valve a greater movement. Conversely, when the knob I6 is turned to allow the valve llll to move outwardly a proportionately greater fluid pressure is admitted to the interior of the compensator tube 90 for a given increase of pressure in the line 50 and this results in a proportionately greater motion of the nozzle 63 away from the blade I2. Accordingly, a given movement or the blade 12 in response to a given liquid level change produces a proportionately smaller increase and the pressure applied to the motor valve 2| and the motion of the valve is thus reduced.

It is to be understood that the control is constant or continuous in operation without any sudden changes or interruptions in action. The pilot control is accurate and sensitiv throughout any portion of a wide range of action, this,

characteristic being due to the throttle range adjustment and the associated parts. The pilot may be readily adjusted to provide for any'level adjustment as required without disturbing any parts of the liquid level responsive means I0.

Having described only a typical preferred form and application of my invention, I do not wish to be limited or restricted to the specific details herein set forth, but wish to reserve to myself any variations or modifications that may appear to those skilled in the art or fall within the scope of the following claims.

Having described my invention, I claim:

1. A control for a fluid vessel having a member movable in response to variations in the level therein and having a fluid pressure actuated valve for governing the level, the control comprising a conduit carrying fluid pressure for actuating the valve, a relay interposed in said conduit to govern the magnitude of the actuating pressure applied to the valve, a Bourdon tube, bleed means for the relay adapted to control the operation of the relay, the bleed means including a second tube extending through the Bourdon tube and a discharge nozzle tor said second tube at the outer end of the Bourdon tube, a part movable by said member and operable to control the nozzle and thus control the relay, and regulable means for delivering fluid pressure to the Bourdon tube to cause movement of the nozzle relative to said part.

2. A control for a. fluid vessel having a member movable in response to variations in the level therein and having a fluid pressure actuated valve for governing the level, the control comprising a conduit carrying fluid pressure for actuating the valve, a relay interposed in said conduit to govern the magnitude of the actuating pressure applied to the valve, a Bourdon tube, bleed means for the relay adapted to control the operation of the relay, the bleed means including a second tube extending through the Bourdon tube and a discharge nozzle for said second tube at the outer end of the Bourdon tube, a part movable by said member and operable to control the nozzle and thus control the relay, regulable means for delivering fluid pressure to the Bourdon tube to cause movement .of the nozzle relative to said part, and means supporting said tubes so that they may be mounted to have said nozzle at either side ofsaid member for cooperation with said part for either direct action or reversed action of the control.

3. A control for a fluid vessel having a member movable in response to variations in the level therein and having a fluid pressure actuated valve for governing the level, the control comprising a conduit carrying fluid pressure for actuating the valve, a relay interposed in said conduit to govern the magnitude of the actuating pressure applied to the valve, a Bourdon tube, bleed means for the relay adapted to control the operation of the relay, the bleed means including a second tube extending through the Bourdon tube and a discharge nozzle for said second tube at the outer end of the Bourdon tube, a part movable by said member and operable to control the nozzle and thus control the relay, regulable means for delivering fluid pressure to the Bourdon tube to cause movement of the nozzle relative to said part, means for operatively associating said part with the member to project from one side of the member for direct action control and to project from the other side of the member for reversed action control, and means supporting the tubes for ready movement between the positions where the nozzle is operatively related to said part in either of said positions.

4. A control for a fluid vessel having a member movable in response to variations in the level therein and having a fluid pressure actuated valve for governing the level, the control comprising a conduit carrying fluid pressure for actuating the valve, a relay interposed in said condull: to govern the magnitude or the actuating pressure applied to the valve, bleed means for controlling the relay, a discharge nozzle for the bleed means, means for optionally supporting the nozzle at either side oi! the member, a blade pivoted on the member for controlling the nozzle, and a contactor on the member for positioning the blade for cooperation with the nozzle when aasasro swung to extend from either side of the member.

5. A control for a fluid vessel having a member movable in response to variations in the level therein and having a fluid pressure actuated valve for governing the level, the control comprising a conduit carrying fluid pressure ior actuating the valve, a relay interposed in said conduit to govern the magnitude oi the actuating pressure ap. plied to the valve, bleed means for controlling the relay, a discharge nozzle for the bleed means, means for optionally supporting the nomle at either side of the member, a blade pivoted on the member for controlling the nozzle, a movable contactor on the member for positioning the blade for cooperation with the nozzle when swimg to extend from either side 01' the member, and means for adjusting the contactor to vary the "level" adjustment of the control.

GLENN I". BROCKE'I'I.