AU2016239671B2 - A cylinder valve with integrated pressure regulator - Google Patents

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).

Any discussion of the prior art throughout the specification should in no way be considered as an admission that such prior art is widely known or forms part of common general knowledge in the field.

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, the valve comprising a housing containing:

a shut off valve element to control the flow of gas

from an outlet of the valve;

a regulator to reduce the pressure of the gas from a

cylinder to which the valve is attached, in use; and

a pilot regulator controllable via an actuator to set

the pressure at which the regulator delivers gas to the

outlet valve, 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.

Unless the context clearly requires otherwise, throughout the description and the claims, the words "comprise", "comprising", and the like are to be construed in an inclusive sense as opposed to an exclusive or exhaustive sense; that is to say, in the sense of "including, but not limited to".

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.

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 10C 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 P1 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 Pl. This causes gas at the regulated

pressure P1 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 P1 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 0-ring 16 with the

smaller diameter portion 13 of the chamber. A larger

diameter portion 17 of the piston 11 is sealed by an 0-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 P1 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 P1 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 P1 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 P1 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

P1 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 P1 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 0-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 P1 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 P1 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

P1. However, gas at regulator pressure P1 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 10C 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 P1

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 Pl. 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 - 10C. 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

10C. 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 (7)

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 an outlet of the valve;

a regulator to reduce the pressure of the gas from a

cylinder to which the valve is attached, in use; and

a pilot regulator controllable via an actuator to set

the pressure at which the regulator delivers gas to the

outlet of the outlet valve, 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.

2. A valve according to claim 1, wherein the pilot

regulator has a positive seat valve element.

3. A valve according to claim 1, 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.

4. A valve according to claim 1 or claim 3, further

comprising a motor to move the pilot valve element.

5. A valve according to claim 4, 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.

6. 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.

7. A cylinder of pressurised gas with a valve according to

any one of the preceding claims.