WO2016156519A1

WO2016156519A1 - A cylinder valve with integrated pressure regulator

Info

Publication number: WO2016156519A1
Application number: PCT/EP2016/057116
Authority: WO
Inventors: Christopher John COWLES; Colin HADEN; Duncan Wales; Mark MELLORS
Original assignee: Linde Aktiengesellschaft
Priority date: 2015-03-31
Filing date: 2016-03-31
Publication date: 2016-10-06
Also published as: GB201505509D0; EP3278007A1; EP3278007B1; AU2016239671B2; AU2016239671A1; CA2981101A1

Abstract

A cylinder valve with integrated pressure regulator. The valve comprises a housing containing a shut off valve, to control the flow of gas from the valve, a regulator, to reduce the pressure of the gas from the cylinder, and a pilot regulator. The pilot regulator is controllable via an actuator to set the pressure at which the regulator delivers gas to the outlet valve.

Description

A CYLINDER VALVE WITH INTEGRATED PRESSURE REGULATOR

The present invention relates to a cylinder valve with integrated pressure regulator. Such valves are known in the art as VIPRs (Valves with Integrated Pressure Regulator) .

Such valves are fitted on gas cylinders in order to reduce the pressure from the gas cylinder (often at a pressure of 300 bar or more) down to an outlet pressure, typically below 10 bar.

Although reference is made to a "cylinder" valve, it will be understood that the invention is applicable broadly to all portable pressurised gas containers including gases stored under pressure as liquids whether they are strictly in the form of a cylinder or not.

Such cylinders are used to supply gas for a range of applications including welding and cutting hoses and

torches, gas packaging machines and laboratory equipment.

Using a VIPR this equipment can be connected directly to the valve outlet without the need for an additional externally connected regulator. The regulator needs to be adjustable to allow a user to supply gas at the required pressure and flow rate for a given application. For example, different flow rates of shielding gas are normally requires for different material thicknesses during welding processes. Further, the majority of VIPRs need adjusting several times a day to alter the pressure or flow rate as the cylinder pressure drops and consequently outlet pressure increases. Conventionally in a VIPR, the force required to adjust the outlet pressure of the regulator is provided by the application of a manually applied torque rotating a hand wheel. The pressure required is dependent upon the outlet pressure requirements and increases as the outlet pressure increases. This torque demand can often be demanding for the user, particularly when dealing with a high outlet pressure. If the regulator is intended to be operated using an electric motor

controlled by on-board power supply, the torque and

therefore energy requirement of the regulator may become prohibitive in terms of the capacity required from the on^¬ board power supply.

According to a first aspect of the present invention there is provided a cylinder valve with integrated pressure regulator as defined in claim 1.

By including a pilot regulator into the housing to supply a control pressure to the regulator, the torque or power required to adjust the outlet pressure setting is greatly reduced. In the case of a manually activated device, this makes it far easier for a user to make the required

adjustment to the regulator. For an electronic actuator, this reduces the demand on the on-board power supply.

Pilot operated pressure regulators are known in other fields. However, these are generally large scale devices in which the pilot valve is a separate component in its own housing which is connected to the regulator via a pipe.

Such pilot operated regulators are designed for applications which require a high level of outlet pressure accuracy.

They are not used to reduce the operating torque required to adjust the regulator as the regulators are operated using mains power. They are not used in pressurised cylinder applicators as these rely on direct action mechanical means for valve closure/opening and pressure adjustment.

Therefore, existing pilot valves are not configured in the same manner as in the present invention in that they are not within the housing containing the shut off valve and

regulator. As well as being configured differently, they are used in an entirely different field for an entirely different purpose.

The primary drivers of the present invention are to make a small device as it is required to fit on the cylinder and to reduce the torque necessary to operate the regulator.

Preferably, therefore, the pilot regulator has a positive seat valve element. The positive seat valve element is one which seats on the low pressure side of its corresponding valve port as opposed to a reverse seat valve which passes through the port and seats on the high pressure side. Such a valve element requires a significantly smaller diameter seat than a reverse seat valve for the same flow

requirement. This allows a smaller piston size for the same accuracy. The smaller piston size reduces the upward force from the gas pressure which allows the biasing springs to be smaller and requires less torque to adjust.

The pilot regulator preferably has an inlet port in

communication with high pressure gas from the cylinder and a pilot valve element biased towards the inlet port to control the flow of gas through the inlet port, a biasing element providing a biasing force on the pilot valve element and being adjustable by an actuator to control the pressure of pilot gas passing through the inlet port to the regulator to vary the force on a restricting element in the regulator. The biasing element may be a single spring positioned between the actuator and the pilot valve element. However, preferably, the biasing element is arranged to bias the pilot valve element open while a balancing biasing element is positioned between the pilot actuator and the pilot valve element to provide an opposing force on the pilot valve element. The presence of the balancing element allows a smaller package for the pilot regulator.

The pilot valve element may be manually operated, in which case it requires less effort from a user to adjust the regulated pressure. Alternatively, the pilot valve element is operated by a motor. In this case, there may further comprise a control system to control the operation of the motor, the control system including a transmitter and receiver to receive and transmit data concerning the control of the pilot valve element.

The valve may be provided with a means to display one or both of the cylinder pressure and the regulated pressure. However, preferably, it further comprises a single gauge for receiving and displaying both the cylinder pressure and the regulated pressure.

This forms a second aspect of the present invention which is a cylinder valve according to claim 9. An example of a cylinder valve with integrated pressure regulator will now be described with reference to the accompanying drawings, in which: Fig. 1 is a schematic cross-sectional view showing the operation of the three main elements of the valve;

Fig. 2 is a more detailed cross-section of the pilot

regulator;

Fig. 3 is an axial cross-section in plane III-III in Fig. 4 through a cylinder valve showing the outlet valve;

Fig. 4 is a cross-section in a horizontal plane shown as IV- IV and regulator in Fig. 3 showing the cross-section of the pilot regulator and regulator;

Fig. 5 shows the pilot regulator and regulator as shown in Fig. 1 as applied to an electronically controlled system;

Fig. 6 is a schematic view of a system used with the

electronically controlled device of Fig. 5;

Fig. 7 is a schematic view similar to Fig. 6 in which process equipment receives gas from more than one bottle;

Fig. 8 is a schematic overview of the layout of a dual gauge system; Fig. 9 is a schematic cross-sectional view showing the dual gauge system; Figs. 10A to IOC are front views of possible gauge face layouts; and

Fig. 11 is a view similar to Fig. 1 showing an alternative layout of the components.

The present invention relates to an improvement to a valve with integrated pressure regulator (VIPR) . Such valves are known for use on cylinders or bottles of pressurised gas. Similar valves are also used in health care applications but have a pre-set pressure and adjustable volumetric flow output. An example of a known valve is disclosed in EP 0747796. The improvement provided by the present invention is the introduction of a pilot regulator and the description below will focus on this and the manner in which it interfaces with the regulator and the shut off valve. This will be described, in particular, with reference to Figs. 1 to 4. Fig. 1 provides a schematic layout of the arrangement while Figs. 3 and 4 show the integration of the various components shown in Fig. 1 into a practical housing. Fig. 2 provides for the detail of the pilot regulator.

The shut-off valve 1 has a generally conventional

construction. It comprises a shut-off valve element 2 urged onto a valve seat 3 by a spring 4. The shut-off valve element 2 and spring 4 are within a chamber which is exposed to a regulated pressure PI as described in greater detail below. This pressure exerts a closing force on the shut off valve element 2. The shut-off valve element 2 is displaced from the valve seat 3 by the depression of a spindle 5 which is pushed downwardly by the operation of a lever (not shown) connected at opening 6 via an eccentric coupling which converts rotational movement of the lever into downward movement of the spindle 5. The return spring 7 biases the spindle upwardly to assist in the closure of the valve.

Turning of the lever depresses the spindle 5 which opens the shut-off valve element 2 against the action of the spring 4 and regulated pressure PI. This causes gas at the regulated pressure PI to be emitted from the outlet 8.

The shut-off valve can alternatively be integrated into the high pressure region upstream of the regulator 10 and pilot regulator 30.

The regulated pressure PI is created by a combination of the regulator 10 and pilot regulator 30 as described below. Both the regulator 10 and the pilot regulator 30 receive high pressure gas at a pressure P2 which is the pressure within the cylinder to which the valve is connected.

The regulator 10 has a regulator element in the form of a piston 11 slidable within a regulator chamber 12.

Alternatively, a flexible diaphragm or bellows could be used. The chamber 12 has a stepped bore with a smaller diameter portion 13 on the high pressure side and a larger diameter portion 14 on the regulated pressure side. The piston 11 has a correspondingly stepped construction with a smaller diameter portion 15 sealed by an O-ring 16 with the smaller diameter portion 13 of the chamber. A larger diameter portion 17 of the piston 11 is sealed by an O-ring 18 with respect to a large diameter portion 14 of the chamber. A bore 19 extends axially down the centre of the piston 11 connecting the high pressure side P2 of the regulator with the regulated pressure side PI as described below. A bleed port 30 is provided through the larger diameter portion 14 of the piston 11. The bleed part 30 allows a flow of gas from the pilot pressure P3 to the lower regulated pressure PI and enables the pilot control pressure to continuously vary. The piston 11 is urged downwardly by a spring 21 urging a tapered lower end 22 towards a seat 23.

The chamber 12 above the piston 11 is connected to the pilot regulator 30 via a regulated pressure line 24 and is

connected to the shut off valve 1 via a regulated pressure outlet line 25. The large diameter portion 14 of the regulator chamber 12 below the large diameter portion 17 of the piston 11 is provided with gas at a pilot pressure P3 via a line 26.

The downward force (using the orientation of Fig. 1) on the piston 11 is a combination of the spring force provided by spring 21 together with the pressure PI acting on the available upwardly facing piston surface. The upward force on the piston 11 is provided by a combination of the pilot pressure P3 on the downwardly facing surface of the piston and the cylinder pressure P2 on the downwardly facing portion of the smaller diameter portion 15 of the piston. One example of the pilot regulator 30 will now be described. The pilot regulator 30 comprises a pilot regulator element in the form of a piston 31 which is housed in a pilot regulator chamber 32, the piston 31 is biased upwardly (in the orientation shown in Fig. 1) by a pilot regulator spring 33 and is biased in the opposite direction by a balancing spring 34. The force balance on the piston 31 is adjustable via actuator stem 35 which bears against the top of

balancing spring 34. The net effect of the pilot regulator spring 33 is less than that of the balancing spring 34. A downward force is exerted by the pressure PI and an upward force by the pilot regulator sping 33. The balancing spring 34 serves to reduce the net effect of the pilot regulator spring 33 and therefore provides a simple method of

adjusting the overall force balance. The actuator stem 35 is the means by which the user adjusts the regulated pressure PI ultimately emitted from the cylinder and this is done using a very small force as described in greater detail below. This either makes the manual adjustment of the regulated pressure easier for a user or reduces the power consumption of any electronic actuation assembly. The surface of the piston 31 in the upper part of chamber 32 receives the regulated pressure PI via the regulated

pressure line 24, while the downwardly facing surface of the piston is open to atmosphere via vent 36. A positive seat pilot regulator valve element 37 extends downwardly from the piston 31 and seats on a valve seat 38 which can be

significantly smaller than the valve seat 23 of the

regulator 10. The positive seat pilot regulator valve element 37 passes through an O-ring seal 39 to seal the valve seat 38 from being exposed to atmospheric pressure. As a result of this, the region in the vicinity of the valve seat 38 is held at the pilot pressure P3 which is transmitted to the regulator along the pilot pressure line 26.

The piston 31 is therefore biased downwardly by a

combination of the spring force from the balancing spring 34 and the relatively low regulated pressure PI acting on the large piston surface 31. It is biased upwardly by a

combination of the biasing force from the pilot regulator spring 33, atmospheric pressure on the lower surface of the piston 31 and the high cylinder pressure P2 acting on the positive seat pilot regulator valve element 37. Raising the actuator stem 35 opens the pilot regulator valve element 37. This causes P3 to rise, this increases the pressure beneath piston 11 lifting it and causing PI to rise.

The pilot regulator valve element is significantly smaller than the smaller diameter portion 15 of the regulator 10 so that the surface area exposed to high pressure acting on the piston 31 is significantly less than the high pressure acting on the piston 11. As a result if this, the spring force required to bias the piston 31 can also be

significantly reduced in comparison to a standard regulator construction . Although one example has been described here, other

variations are contemplated. The valve elements in the regulator and pilot regulator could be reverse seat valves, the pistons in the regulator and pilot regulator could be replaced by a diaphragm or bellow, and the shut off valve could be an upstream valve. This latter arrangement is illustrated in Fig. 11. The three components, namely the shut off valve 1, regulator 10 and pilot regulator 30 are the same as previously described. The only difference is that the shut off valve is now upstream of the regulator 10 and pilot regulator 30. The pilot regulator 30 operates in exactly the same manner as before and the various chambers are exposed to the same temperatures. The only difference is that they receive the high pressure cylinder gas downstream of the shut off valve 1. While the structure of the shut off valve remains unchanged, the shut off valve element 2 is now exposed to the cylinder pressure P2 rather than the regulator pressure PI. However, gas at regulator pressure PI is emitted to the downstream equipment as before.

Figs. 5 to 7 show the manner in which the previously

described valve is integrated into an electromechanically actuated device. In Fig. 5, the regulator 10 and pilot regulator 30 are as previously described. The actuator stem 35 is provided with a screw thread and is connected to a motor such as a small brushed DC motor. The motor is controlled by a control system comprising a power supply 41 such as a battery, a memory 42, a means of transmission 43 which may be a wired connection or any known wireless connection, a receiver 44 which again may have a physical connection or be wireless and a processor 45. These components form a control module 46 which is connected to the housing for the cylindrical valve. Fig. 6 shows a use of the arrangement shown in Fig. 5.

Here, the control module 46 is attached to a cylinder C. The means of transmission 43 and receiver 44 can communicate with process equipment 47 to make necessary adjustments to the actuator stem 35 of the pilot regulator 30 to control the pressure of gas supplied to the process equipment 47 along line 48. This system may also include pressure sensors in the line 48 and/or process equipment 47.

Communications devices 49 are in two way communication with the control module 46 to allow a user to monitor and control the output from the cylinder C.

A variation of this second implementation is shown in Fig. 7 in which two cylinders C supply gas along gas supply lines 48 to a mixing buffer which can supply a mixture of gas to process equipment 47 via a mixing buffer 50. The control modules 46 on the cylinders C are controlled to supply gas in the correct ratios to the mixing buffer 50. Figs. 8 to IOC show an arrangement of a gauge G which is particularly suited to use with the present invention.

In particular, the gauge is designed to display to the user both the cylinder pressure P2 and the regulated pressure PI on a single gauge.

A cylinder pressure inlet 60 in the gauge G is in

communication with one of the gas paths that is at the cylinder pressure P2. Similarly, a regulated pressure inlet 61 is in communication with one of the paths at the

regulated pressure PI. The high pressure inlet 60 leads to a high pressure bourdon tube 62 which leads to a high pressure needle 63 to indicate on a high pressure scale 64 the level of the high pressure P2. A number of high

pressure gauges are shown in Figs. 10A - IOC. Similarly, the regulated pressure inlet 61 is connected to a low pressure bourdon tube 65 connected via a linkage 56 and rack and pin mechanism 67 to a regulated pressure needle 68 which displays the level of the regulated pressure to a user on a regulated pressure scale 69, again as shown in Figs. 10A to IOC. Alternatively a digital display may be used. It would be appreciated, however, that the dial provides a convenient and compact way of displaying both pressures to a user.

Claims

1. A cylinder valve with integrated pressure regulator, the valve comprising a housing containing:

a shut off valve element to control the flow of gas from the valve;

a regulator to reduce the pressure of the gas from the cylinder; and

a pilot regulator controllable via an actuator to set the pressure at which the regulator delivers gas to the outlet valve.

2. A valve according to claim 1, wherein the pilot regulator has a positive seat valve element.

3. A valve according to claim 1 or claim 2, wherein the pilot regulator has an inlet port in communication with high pressure gas from the cylinder and a pilot valve element biased towards the inlet port to control the flow of gas through the inlet port, a biasing element providing a biasing force on the pilot valve element and being

adjustable by the actuator to control the pressure of pilot gas passing through the inlet port to the regulator.

4. A valve according to claim 3, wherein the biasing element is arranged to bias the pilot valve element open while a balancing biasing element is positioned between the pilot actuator and the pilot valve element to provide an opposing force on the pilot valve element.

5. A valve according to claim 3 or claim 4, further comprising a motor to move the pilot valve element.

6. A valve according to claim 5, further comprising a control system to control the operation of the motor, the control system including a transmitter and receiver to receive and transmit data concerning the control of the pilot valve element.

7. A valve according to any one of the preceding claims, further comprising a single gauge for receiving and

displaying both the cylinder pressure and the regulated pressure .

8. A cylinder of pressurised gas with a valve according to any one of the preceding claims.

9. A cylinder valve with integrated pressure regulator, the valve comprising a housing containing:

a shut off valve element to control the flow of gas from the valve;

a regulator to reduce the pressure of the gas from the cylinder; and

a single gauge for receiving and displaying both the cylinder pressure and the regulated pressure.