US2770251A - Quick-acting reducing valve - Google Patents

Description

United States Patent O QUICK-ACTIN G REDUCING VALVE Application June 25, 1953, Serial No. 364,095

1 Claim. (Cl. 137-488) This invention relates to a valve particularly designed for reducing and controlling heavy gas pressures 1n combustion apparatus.

It is the general object of the invention to provide a reducing valve which will provide and maintain a heavy uniform operating pressure. A further object is to provide a reducing valve having special provision for qulck response to a drop in pressure in the controlled apparatus.

The invention further relates to arrangements and combinations of parts which will be hereinafter described and more particularly set forth in the appended claim.

\A preferred form of the invention is shown in the drawing which is a sectional side elevation of the improved reducing valve.

`Referring to the drawing, the valve V comprises a body having an inlet pipe 11 `and an outlet pipe 12. The inlet pipe 11 is to be connected to any suitable supply of high pressure gas, and the pipe 12 may be connected to a tank T or to any other apparatus in which a uniform but reduced gas pressure is to be maintained.

The pipe 1'1 is connected into a lower chamber 15 in the body 10, and the pipe 12 is connected into an upper chamber 16. The chambers 15 and 16 are separated by 4a partition 18 having a reduced connecting opening or port 19.

A valve member is positioned below the port 19, and a spring 21 tends to raise the valve member 20 to closing position. The lower end of the spring 21 is seated in a recess 22 in a cap or nut 23 which also closes the lower end of the chamber 15.

A control unit U is mounted above the valve V and comprises a main casing 30 having a downward projection 31 adapted to be threaded into the upper end of the body 10. A bellows B is housed in the casing 30, and the lower or free end of the bellows is rmly secured to a movable bottom plate 32.

The upper end of the bellows B is secured in a ring 34 which is clamped between the upper surface of the casing 30 and the under side surface of a casing head 35, these parts being firmly held together by screws 36.

A casing member V2 is mounted on the bottom plate 32 and encloses a valvedopening plunger 40 pressed upward by a coil spring 41, so that it normally closes a port 42 in the upper end of the casing member. The lower end of the plunger 40 engages a second plunger 4S slidable in an axial passage in the downward projection 31 of the main casing 30.

At its lower end, the plunger 45 is reduced, as indicated a't 46, and passes loosely through the port 19 to engage the head of the valve member 20. When the bottom plate 32 is in its lowest position, as indicated in the drawing, the plungers 40 and 45 are of such length that the valve 20 will be forced downward to open the port 19.

Relatively heavy springs S and S2 are provided within the bellows B, and at their lower ends they engage and press downward the bottom plate 32. At their upper ends, they engage a cap 47 loosely mounted at the lower end of an adjusting screw 48 which is threaded into the upper 2,770,251 Patented Nov. 13, 1956 end of the casing head 35. By turning the screw 48, the pressure of the springs S and S2 may be adjusted.

The apparatus thus far described operates as follows:

The valve V is normally open. When pressure is admitted through the pipe 11, gas under pressure llows through the port19 to the outlet pipe 12 and tank T.

Small holes H are provided in the casing extension 31,

and as pressure rises in the outlet pipe 12 and tank T, increased' pressure is applied through the holes H to the under side of the bottom plate 32. This pressure eventually` overcomes the springs S and `S2 and raises the bottom plate 32 and casing member V2. The valveopening plunger 40 likewise rises and permits the lower plunger 45 and the valve member 20 to rise and to thereby decrease the open area of the port 19. In due course, these parts will assume a substantially static position, with the port 19 open just enough to maintain the desired reduced pressure in the tank T or in other apparatus to which the reducing valve V is connected. The exact amount of this reduced pressure may be determined by the setting of the adjusting screw 48.

Special provision is made for restoring the desired uniform pressure, when an increase in demand on the tank T or other operated apparatus causes a drop in the pressure to be uniformly maintained.

iFor this purpose, a by-pass connection 50 extends from the tank T to an auxiliary valve V3, which in turn is connected by a pipe 51 into the casing head 35 and hence into the interior of the bellows B. The valve V3 comprises a cylinder 60 having a piston 61 mounted on a piston rod 62 which is freely slidable axially. An auxiliary pressure tank T2 is connected with the cylinder 60 by a pipe 64 positioned opposite the pipe 51 previously described.

When the tank T is under normal reduced pressure, this normal pressure is applied through the pipe 50 to the right-hand end of the cylinder 60 and holds the piston 61 against stop-pins 66, at the same time compressing a coil spring 67. In this position, the piston 61 closes the pipes 64 and 51.

At this same time, a second piston 70 assumes the position shown in the drawing and uncovers the upper end of a by-pass connect-ion 72 between the pipe 51 and a vent 73, so that the pressure in the interior of the bellows B is atmospheric and there is no downward gas pressure on the bottom plate 32.

If an `increased demand on the tank T or other apparatus causes a drop in the selected reduced pressure, the pressure in the auxiliary cylinder 60 correspondingly drops, so that the spring 67 overcomes the pressure in the cylinder 60 and moves the pistons 61 and 70 to the right. The piston 70 thereupon closes the: venting by-pass 72, and the piston 61 uncovers the auxiliary pressure pipe 64 and opens the connection thereof through the pipe 51 to the interior of the bellows B.

yAdditional pressure is thus exerted on the bottom plate 32, forcing it to move downward against the pressure on the under side of the pl-ate and thus further depressing the valve member 20 and increasing the operative area of the port 19. An increased llow of gas through the outlet pipe 12 to the tank T then takes place, and the desired uniform pressure is restored.

As the action of the relatively large bellows B is rather slow, the casing member V2 and plunger 40 are provided to produce quicker action. As soon as the auxiliary valve V3 has admitted pressure to the control unit, the increased pressure acts directly on the plunger 40, depressing the valve plunger and promptly pushing the valve member 20 downward without waiting for the relatively slow downward movement of the bottom plate 32.

`Provision is thus made for maintaining and restoring a deslred uniform pressure in the tank T or other apparatus, and also for inducing quick action on the event of `a ysudden drop in pressure on the tank T.

The apparatus above described has been found effective and satisfactory in controlling pressures as high as 800 lb's. per square inch, y Y

Having thus described the invention and the advantages thereof, it will be understood that the vinver'ition is not to be limited to the details herein disclosed, otherwisevthan as set forth inthe claim, but what is claimed is:

A quick-acting reducing valve for a controlled pressure system comprising ya valve body having inlet and discharge connections, .an interposed port and .a valve member therefor, .a spring to move saidy valve member inra direction to close said port, a control unit comprising'an actuating part movable to engagey and shift saidvalve-member to open said port, springs to effect such movement of said actuating part, a Vpressure connection between the discharge passage of said reducing valve and said'control unit, whereby the discharge pressure balances the spring pressure at a predetermined regulating position of said valve member, and said control unit including a bellows member, means to .admit auxiliary air under pressure from an auxiliary air supply to said bellows member to further open said reducing valve on a drop in pressure in the controlled system, and quick-acting auxiliary means to accelerate the valve-opening action of said actuating part, and said quick-acting auxiliary means comprising a member in said control unit, which member is directly exposed to said auxiliary air under pressure and which member -acts directly to move said actuating part and to thereby quickly open said reducing valve when said member is moved by said auxiliary air under pressure and before the bellows member' completes its relatively slow response tol said auxiliary air pressure..

References Cited in the iile of this patent UNITED STATES PATENTS

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