EP2522570B1

EP2522570B1 - Regulator valve of a circuit for reclaiming gas exhaled by a diver

Info

Publication number: EP2522570B1
Application number: EP20120425072
Authority: EP
Inventors: David Marzi
Original assignee: BRUCE OFFSHORE Ltd; Comea Srl
Current assignee: BRUCE OFFSHORE Ltd; COMEA Srl
Priority date: 2011-04-11
Filing date: 2012-04-06
Publication date: 2013-10-09
Anticipated expiration: 2032-04-06
Also published as: EP2522570A8; EP2522570A1; ITRM20110182A1

Description

The present invention concerns a regulator valve of a circuit for reclaiming gas exhaled by a diver.
More in detail, the invention relates to a device of the said kind, provided with specific devices operating in emergency situations.
As it is well known, in cases where the gas delivered to a diver during the dive is constituted by elements or mixtures of gaseous elements that can be convenient to recover, such as for example helium or mixtures of helium with oxygen and/or air, the gas exhaled by the diver can be sent to the surface and elements contained therein can be recovered by means of a gas extraction system. In particular, the reclaim conduit connecting the helmet (or the breather) of the diver with the extraction system at the surface operates under a slight under vacuum with respect to the diver's exhalation pressure. For safety and health reasons, the reclaim conduit, operaing under vacuum must be kept separate, except for the step of exhalation, from the helmet or from the breather of the diver and, therefore, from the diver's respiratory system. For this reason, between the helmet/breather and the reclaim conduit is arranged a valve, commonly called reclaim valve, or more properly regulator valve of the reclaim circuit of the gas exhaled by the diver or GRBPR (Gas Reclaim Back Pressure Regulator).
The operating principle of a regulator valve of this kind, in the following always indicated by the acronym GRBPR, is the same of a common two-stage balanced pressure reducer. The normal operation of this kind of reducers is providing an accurate, constant and linear outlet pressure, decreasing the inlet pressure from a higher value to the outlet value. These reducers, in general, are comprised of two interconnected chambers, the first chamber being in contact with the pressure to be reduced (source), the second being the chamber designed to reduce pressure, wherein, in general, gas expands and thus is reduced. Such a pressure reduction can be obtained by various methods. In general, the most commonly used systems are two:

one using two interbalanced membranes, one of which being designed to ensure the closing and then also operating as safety valve;
one using a piston provided with special orifices allowing the gas to pass from a chamber to the other, in general the piston also operating as a safety valve, ensuring the closing of the main chamber when the second chamber reaches the desired pressure.

In the case of interest for the purposes of the present invention, it is used the same operating principle described with reference to the first case, i.e. that using two membranes, suitable for the specific needs of an underwater application.
In particular, the reducer's inlet and outlet are designed for being connected to a professional diving helmet. The GRPBR reducer is therefore connected to the outlet of the helmet of a diver, to allow recovery of the exhaled gas through a conduit conducting the gas itself to the extraction system at the surface.
A regulator valve of this kind is disclosed in US patent N. US4625759 , according to which the regulator valve of the gas reclaim circuit is made of a body inside which are defined:

a first chamber, arranged between a first diaphragm and a first separator plate, the function of which is to receive exhaled gas, and
a second chamber, arranged between a second separator plate and a second diaphragm, on the opposite part of the first separator plate with reference to the first diaphragm.

A passage element having cylindrical shape interconnects the two chambers and its lower end serves as a seat for the first diaphragm, shutting the passage between the two chambers in case the pressure inside the first chamber gets lower than the external pressure pressing on the first diaphragm, for example in the phase of inhalation by the diver. The second separator plate, moreover, has frustoconical shape, with the smaller base connected to the passage element, and is provided with slots constituting the connection with a further chamber in direct contact with the reclaim conduit. The surface of the separator plate facing towards the second diaphragm serves as a seat for the diaphragm itself, in case the pressure inside the second chamber gets lower than the external pressure pressing on the second diaphragm, for example in the phase of inhalation by the diver. Moreover, on the second diaphragm acts a spring, arranged in the cylindrical passage element, with the function of counteracting a part of the external pressure, so to ease the lifting of the second diaphragm operated by the gas exhaled by the diver.
Thanks to this configuration, the first diaphragm operates in collaboration with the lower end of the passage element, so to create the first stage of the valve, whereas the second diaphragm operates together with the second separator plate, provided with slots, so to create the second stage of the valve.
In case of failure of the reclaim system, the regulator valve can be insulated by the reclaim conduit, by shutting a shut-off valve, downstream the regulator valve, not disclosed in US4625759 .
The valve disclosed in US4625759 has different limits and in particular:

inability to perform a thorough cleaning of the inner chamber of the valve (first chamber) the first separator plate being welded with the valve body;
non repeatability of works, the valve being formed by couplings made with manual welding processes;
possibility of deformation due to thermal shock, due to the rigidity of the internal elements of the valve due to the welds inside the valve body;
inability to perform an accurate control of the inside of the valve chamber (first chamber) in the welding area, where there may be processing wastes and roughness, these definitely causing a buildup of residues; and
reduction in performance due to poor maintainability of the valve body.

Moreover, the regulator valve disclosed in US4625759 , in the embodiment actually marketed, leads to further problems and limitations:

difficulty performing the removal and installation of the filter;
possible rupture of the filter during the normal work of the valve, probably because of the continuous deformation of the filter due to its removal/installation; and
need for changes to the helmet on which the valve is installed, voiding the CE certification of the helmet itself, due to changes in its structure.

Some of these limitations are addressed and overcome by the solution proposed according to the US patent application N. US 2008/0178883 , according to which the assembly of a valve for reclaiming the gas exhaled by the diver is made of two chambers, by means of which the gas exhaled by the diver is delivered to the reclaim unit over the sea surface, the regulator valve (GRBPR) being connected to an inlet tube, to which the exhaled gas coming from the diver's helmet is delivered by a switching block.
The switching block is connected to the diver's helmet by a mounting plate. On the opposite side of the switching block with respect to the mounting plate, a movable handle is present, by which the gas reclaim circuit can be opened or closed using a single hand..
When the circuit is closed, the exhaled gas passes in sequence first through the inlet tube, then in the regulator valve and from that it flows, through the two chambers, to the reclaim conduit, through which ot arrives at the reclaim unit over the sea surface. When the circuit is open, the exhaled gas is expelled by the system to the external environment, by means of a non-return valve.
In particular, the regulator valve of the gas reclaim system according to the patent application N. US 2008/0178883 is used together with a diving helmet and the breathing system thereof and comprises:

a first chamber arranged between a first diaphragm and a separator plate, wherein exhaled gas is received;
a second chamber arranged between said separator plate and a second diaphragm, on the opposite side of the separator plate with reference to the first diaphragm.

The two chambers are interconnected by means of a funnel-shaped base, the narrower part facing towards the first chamber and the wider part facing towards the second chamber and provided with slots. The first chamber is additionally provided with a filter provided with slots having a small diameter, the function of which is to prevent any possible debris from entering the regulator valve and causing its failure.
The first diaphragm operates in cooperation with the narrower part of the funnel-shaped base, so to create the first stage of the valve, while the second diaphragm operates together with the wider portion of the base provided with slots, so to create the second stage of the valve.
The regulator valve of the reclaim circuit disclosed by the patent application N. US 2008/0178883 is connected to an inlet tube from which the gas exhaled by the diver arrives and after passing through the switching block.
The switching block is comprised of two opposed sides: the first side of the switching block is connected to the diving helmet by a mounting plate, whereas the second side of the switching block comprises a movable handle by which the circuit connecting the helmet and the regulator valve of the gas reclaim circuit can be opened or closed.
When the handle is used to open the circuit connecting the helmet and the gas reclaim regulator valve, the gas exhaled by the diver does not pass through the inlet tube of the regulator valve; on the contrary, it is activated a non-return valve that allows the exhaled gas to be expelled by the switching block to the external environment, preventing water to come in contact with the switching block itself.
When the handle is put in the closed position of the reclaim circuit, the gas passes through a delivery tube, to the reclaim regulator valve.
The solution according to the US application N. 2008/01738883 proposes exactly the same of US patent US4625759 , with the difference of the removal of a valve for insulation from the surface and the addition of a switching valve, which allows to perform two operations by a single movement instead of having two valves. This kind of switching valve increases the number of elements of the control system, with the consequence of increasing costs and maintenance. Moreover, the valve according to US application N. 2008/01738883 is designed for a kind of helmet maintaining the exhaust valve inside the helmet (as it can be understood by the fact that means for fixing it to the helmet are not provided). As a consequence, the valve cannot be adapted and, therefore, it is not versatile.
In the light of the above, it is evident the need for a regulator valve of a circuit for reclaiming gas exhaled by a diver overcoming the limits of the regulator valves of the known type.
In this context it is proposed the solution according to the present invention, with the aim of providing for a regulator valve of a circuit for reclaiming gas exhaled by a diver making maintenance easier, preventing any possibility of thermal stresses, making production simpler, which can be easily adapted to different operative depth and can be installed without the help of a qualified technician.
These and other results are achieved according to the present invention by proposing a regulator valve of a circuit for reclaiming gas exhaled by a diver provided with a plate which can be removed, in order to make mounting, maintenance and substitution easier. The solution proposed according to the present invention additionally allows for achieving a plurality of additional technical effects and advantages, as it will be better explained in the rest of the description.
A purpose of the present invention is therefore that of realising a regulator valve of a circuit for reclaiming gas exhaled by a diver that allows to overcome the limits of the solutions according to the prior art and to obtain the previously described technical results.
An additional aim of the invention is that said regulator valve can be realised with substantially low costs.
Not least aim of the invention is that of realising a regulator valve of a circuit for reclaiming gas exhaled by a diver which is substantially simple, safe and reliable.
It is therefore a specific object of the present invention a regulator valve of a circuit for reclaiming gas exhaled by a diver, comprising a valve inlet conduit of exhaled air, directly connected to a valve first chamber, and a valve outlet conduit of exhaled air, connected to a reclaim system over the sea surface by means of a reclaim conduit, said outlet conduit being directly connectable to a second chamber of said valve, said chambers being separated by a separator plate, integral with the body of the regulator valve, said separator plate defining a housing for a plate with orifice, constituted by an inlet portion facing towards said first chamber and by an outlet portion facing towards said second chamber, said plate defining a passage connecting said chambers, said valve further comprising a first membrane, inside said first chamber, for closing said inlet portion of said plate and a second membrane, in correspondence of said second chamber, for closing said outlet portion of said plate, wherein said plate is coupled with said housing defined by said separator plate by means of removable coupling means and preferably by means of screwing of a threaded portion thereof in a corresponding portion of said housing provided with a complementary thread.
Moreover, according to the invention, said plate is made of titanium.
Still according to the present invention, said regulator valve additionally comprises a filter, constituted by a frusto-conical perforated element, laying with its smaller diameter border on said separator plate and with its larger diameter border, the dimension of which is slightly smaller than the internal diameter of the walls of the body of the regulator valve, on a resilient ring seal, housed in a dedicated seat realized on the internal walls of the body of the regulator valve.
Additionally, according to the invention, said inlet portion of said plate facing towards said first chamber is cylindrical and said outlet portion facing towards said second chamber is cylindrical and is provided with slots.
Moreover, always according to the invention, said regulator valve additionally comprises a conduit, directly connected to said first chamber and provided with an exhaust valve and preferably also comprises a shut-off valve, arranged on said reclaim conduit, in proximity of said outlet conduit, more preferably said shut-off valve being arranged at such a distance from said regulator valve that it is arranged, with reference to the helmet of a diver, in a specular position to that of the quick blow-off valve of said helmet.
It is evident the effectiveness of the regulator valve of a circuit for reclaiming gas exhaled by a diver of the present invention, providing for the following advantages:

a) Removable plate, attached by thread to the separator plate of the valve.
b) Improved efficiency in maintenance. Functional cleaning with known and repeatable method. For example: removal of residues/encrustations through the use of a tray with suitable detergent or through ultrasonic mechanical removal, enabling the operator to visually check the result of cleaning.
c) Improvement of the manufacturing process of the orifices of the plate, possibility of dimensional control of the same and possibility of having a better surface quality. Absence of thermal stress of the plate, the same being coupled to the separator plate of the valve by threading and not by welding, keeping geometrical dimensions as designed.
d) Ability to maintain the performance of manufacture for the entire life of the valve, ensuring the identification of any problems due to encrustations or to the presence of external agents and/or deposits.
e) Possibility of mounting plates with different section of the orifices, to ensure maximum performance at different operative depths without having to replace the complete valve. Moreover, by acting on the shape of the orifices themselves, the speed of response of closing and opening the valve can be varied.
f) In the event of damage to the plate, due to scratches and/or cuts located in the area involved in sealing with the membrane, it can be replaced simply by removing the damaged one and installing a new one.
g) Outstanding accuracy and repeatability of the internal volume of the valve, the same being made by machining with the accuracy of tenths of a millimeter.
h) Improved system of fixing the filter inside the valve, this could be installed and removed without having to mechanically deform as in valves disclosed according to the patent US4625759 .
i) Improved fixing of the shut-off valve between the regulator valve and the umbilical valve. This is conveniently positioned symmetrically to the quick blow-off valve located on the opposite side of the helmet. This is an advantage from the point of view of safety, decreasing the overall lateral dimensions of the helmet and then decreasing the possibility that it gets entangled in any underwater structure and especially gives more security to the diver who needs only to associate the position of the same in the opposite side with respect to where the emergency gas inlet is.
l) The strength of the regulator valve according to the present invention is the ability to install the valve without the aid of a specialized technician. In fact, the regulator valve according to the present invention does not require any modification to the structure of the helmet, but simply requires the replacement of some components that will be replaced by those provided as accessories to the valve. All this to avoid the problem of CE certification of the helmet itself, the valve according to the U.S. patent No. U.S. 4625759 presenting the need to modify the structure of the helmet, making holes in the same.
m) No need to move the weight on the right side, the same having to be removed and in its place installed, at the same point, one of lower weight, obviating the problem of the valve according to the patent US4625759 that requires the displacement of the same, beside the fact of having the need to pierce the helmet to re-arrange the weight in the rear position.

The present invention will now be disclosed, for illustrative but not limitative purposes, according to its preferred embodiment, with particular reference to the figures of the accompanying drawings, wherein:

Figure 1 shows a first perspective view of a regulator valve of a circuit for reclaiming gas exhaled by a diver according to the present invention, of part of the reclaim conduit and of a shut-off valve disposed along the same;
Figure 2 shows a second perspective view of the valve of Figure 1, from a different point of view with respect to Figure 1;

Figure 3 shows a sectional view of the valve of Figure 1, along a section plane transverse to the valve body and the inlet duct;
Figure 3a shows a detail of figure 3, concerning the connection between the plate with orifice and the separator plate of the valve of Figure 1;
Figure 4 shows a sectional view of the valve of Figure 1, along a section plane orthogonal to that of Figure 3, ie along a section plane transverse to the valve body, the outlet conduit, connected to the reclaim conduit, and to the exhaust conduit;
Figures 5a and 5b show two different perspective views of the plate with orifice of the valve of Figure 1;
Figure 6 shows a sectional view of the valve of Figure 1, along the same section plane of Figure 3, during the step of exhalation by the diver, and
Figure 7 shows a sectional view of the valve of Figure 1, along the same section plane of Figure 3, during the phases in which the diver does not exhale.

Referring to the figures, according to the present invention is used the same operating principle described with reference to the solutions of the prior art, with the differences which will be explained in the following.
The inlet conduit 11 and the outlet conduit 12 of the GRPBR regulator valve, indicated as a whole with the numeral 10, are designed to be connected to a professional diving helmet.
The valve 10 is connected to the outlet of the diver's helmet, to allow the recovery of the exhaled gas. In the specific case, the valve 10 is fed to its inlet (source) with the gas exhaled by the diver (synthetic mixture consisting of He/O₂ and/or air), which is conveyed in the inlet conduit 11. The inlet conduit 11 is directly connected to a first chamber A of the valve 10. By contrast, the outlet conduit 12 is directly connected to a second chamber C of the valve 10. The first chamber and the second chamber C of the valve 10 are defined within the body of the valve 8 and are separated by a separator plate 9.
On its way inside the valve 10, the gas flows through the filter 13, disposed inside the first chamber A, and comes in contact with the first membrane 14. The accumulation of exhaled gas creates a slight positive pressure with respect to the external environment (environmental pressure), this pressure allowing the lifting of the first membrane 14 and thus the free passage of gas, through the conduit B defined by the plate 15, which is funnel-shaped and constituted by a first cylindrical portion 16 and a second flared portion 17, in the second chamber C, below and adjacent, where the second membrane 18 is present. The passage, as mentioned, is guaranteed by the intermediate conduit B, defined by the area comprised within the cylindrical portion 16 and in sequence within the flared portion 17 of the plate 15. On one side, the cylindrical portion 16 of the plate 15 accommodates a spring 19, which presses on the second membrane 18 of the second chamber C, while on the other side, with the circular edge 20 of its end, it forms the sealing seat of the first membrane 14 of the first chamber A. The first membrane 14, during the intermediate phase of the respiratory stop, will be in the closed position, resting on the seat defined by the circular edge 20 of the cylindrical portion 16 of the plate 15, keeping the passage B between the first chamber A and the second chamber C closed. The actual seal is guaranteed during the inhalation phase of the diver. During this phase, an expansion takes place in the lung which creates by reflection a certain suction and decrease of pressure within the conduit 12 and therefore within the first chamber A preceding the first membrane 14, thus ensuring the sealing of the membrane 14 itself. Moreover, as a result of pressure reduction occurred during the inhalation phase, a push is exherted by the environmental pressure, in connection with the outer surface of the first membrane 14 along a chamber D defined by a top cover 21 provided with openings 22. In fact, at that precise moment, the ambient pressure will be greater than the pressure inside the first chamber A preceding the first membrane 14, ensuring a perfect stability of the system. Moreover, the side walls of the top cover 21, in cooperation with the surface of the upper contour of the body 8 of the valve, bind the contour of the first membrane 14, determining its position inside the valve 10. The top cover 21 is mounted on the body 8 of the valve 10 and is maintained in position thanks to the bond operated by the coupling with a bottom cover 24, mounted on the opposite side of the body 8 of the valve, said coupling being obtained by means of screw pins 32.
As already said, the GRBPR system is usually connected to a surface system, which is at a lower pressure than the outlet pressure of the GRBPR valve 10.
This difference in pressure creates a suction on the reclaim conduit 23 connecting the diver's helmet and the system over the sea surface. This vacuun may cause problems to the lung apparatus of the diver, should there be a malfunction of the system. To ensure that this does not happen, the GRBPR valve 10 is provided with the second membrane 18, which is maintained in the closed position by the action of suction that the system creates inside the second chamber C and by the thrust that the environmental pressure, in connection with the outer surface of the second membrane 18 in correspondence of the chamber E defined by the lower cover 24 provided with openings 25. In consequence of the combined effect of these two actions, the second membrane 18 adheres to the inner surface of the flared portion 17 of the plate 15, closing the slots 26 of which said surface is provided. Moreover, the side walls of the lower cover 24, in cooperation with the surface of the lower contour of the body 8 of the valve, bind the edge of the flared portion 17 of the plate 15 and the contour of the second membrane 18, determining their position inside the valve 10.
As already mentioned, the spring 19 presses on the second membrane 18, in order to help the exhalation of the diver, greatly reducing the exhalatatory effort, within the limits required by the standard reference on breathing apparatus. In fact, as a result of the combined effect of the pressure exerted by the act of exhalation by the diver and by the spring 19 on the second membrane 18, the latter moves away from the inner surface of the flared portion 17 of the plate 15, leaving the slots 26 uncovered, through which the gas exhaled by the diver passes to the second chamber C, and from this, to the outlet conduit 12 and to the reclaim conduit 23.
The peculiarity of the GRBPR valve 10 according to the present invention resides in the fact that the plate 15 of the valve, realized with the funnel shape already disclosed, is not welded to the separator plate 9, as in the solutions according to the prior art, but is provided with a thread 27 which engages with a corresponding complementary thread 28 formed on a housing 29 defined by the separator plate 9, integral with the body 8 of the valve 10. Additionally, between the thread 27 of the plate 15 and the complementary threads 28 of the housing 29 a sealing gasket 30 is disposed, inside a special housing. A further sealing gasket 31 is arranged between the edge of the flared portion 17 of the plate 15 and a special housing provided on the side walls of the body 8 of the valve 10.
In view of the type of installation planned, the plate 15 is made of titanium.
A further peculiarity of the regulator valve of the gas recovery system according to the present invention is constituted by an improved fastening system of the filter 13 inside the valve. The filter 13 is constituted by a perforated sheet, of truncated cone shape. The area of smaller diameter rests on the housing 29 of the separator plate 9 and is concentric with the cylindrical portion 16 of the plate 15. The area of greater diameter, which has a dimension slightly smaller than the inner diameter of the walls of the body 8 of the valve 10, rests on a resilient sealing ring 33. The resilient ring 33 is housed in a dedicated seat realized on the internal walls of the body 8 of the valve 10. As a consequence, once in place, the resilient ring 33 holds the filter 13 in a suitable position. To remove the filter 13 the resilient ring 33 must first be disengaged from its seat; at this point, the filter 13 can slide out from the body 8 of the valve 10.
Thanks to these characteristics, the filter can be installed and removed without having to mechanically deform it.
Finally, using the GRBPR the need has arisen to replicate the normal exhaust valve, in order to eventually restore the original functions of the helmet itself discharging the exhaled gas directly in the external environment through a system of discharge. To ensure that this was possible, a conduit 34 was added to the GRBPR, directly connected to the first chamber A and provided with an exhaust valve 35, which can be used in automatic and/or manual mode. To ensure that the GRBPR system is completely isolated, in order to allow the normal exhaust valve 35 its functionality, a shut-off valve 36 has been added on the reclaim conduit 23, placed adjacent to the outlet conduit 12. By closing the shut-off valve 36 and opening the exhaust valve 35, the helmet will return to have its original characteristics of functionality and will be able to be used in open circuit without any problem.
The present invention has been disclosed for illustrative but not limitative purposes, according to its preferred embodiments, but it is to be understood that variations and/or modifications may be apported by those skilled in the art without departing from the scope of protection, as defined by the appended claims.

Claims

Regulator valve (10) of a circuit for reclaiming gas exhaled by a diver, comprising a valve (10) inlet conduit (11) of exhaled air, directly connected to a valve (10) first chamber (A), and a valve (10) outlet conduit (12) of exhaled air, connectable to a reclaim system over the sea surface by means of a reclaim conduit (23), said outlet conduit (12) being directly connected to a second chamber (C) of said valve (10), said chambers (A, C) being separated by a separator plate (9), integral with the body (8) of the regulator valve (10), said separator plate (9) defining a housing (29) for a plate with orifice (15), constituted by an inlet portion (16) facing towards said first chamber (A) and by an outlet portion (17) facing towards said second chamber, said plate (15) defining a passage (B) for connecting said chambers (A, C), said valve (10) further comprising a first membrane (14), inside said first chamber (A), for closing said inlet portion (16) of said plate (15) and a second membrane (18), in correspondence of said second chamber (C), for closing said outlet portion (17) of said plate (15),
characterised in that
said plate (15) is coupled with said housing (29) defined by said separator plate (9) by means of removable coupling means.
Regulator valve (10) according to claim 1, characterised in that said plate (15) is coupled with said housing (29) defined by said separator plate (9) by means of screwing of a threaded portion (27) thereof in a corresponding portion of said housing (29) provided with a complementary thread (28).
Regulator valve (10) according to claim 1 or 2, characterised in that said plate (15) is made of titanium.
Regulator valve (10) according to any of the previous claims, characterised in that it further comprises a filter (13), constituted by a frusto-conical perforated element, laying with its smaller diameter border on said separator plate (9) and with its larger diameter border, the dimension of which is slightly smaller than the internal diameter of the walls of the body (8) of the regulator valve (10), on a resilient ring seal (33), housed in a dedicated seat realized on the internal walls of the body (8) of the regulator valve (10).
Regulator valve (10) according to any of the previous claims, characterised in that said inlet portion (16) of said plate (15) facing towards said first chamber (A) is cylindrical and said outlet portion (17) facing towards said second chamber (C) is cylindrical and is provided with slots (26).
Regulator valve (10) according to any of the previous claims, characterised in that it further comprises a conduit (34), directly connected to said first chamber (A) and provided with an exhaust valve (35).
Regulator valve (10) according to claim 6, and a shut-off valve (36), arranged on said reclaim conduit (23), in proximity of said outlet conduit (12).
Regulator valve (10) according to claim 7, characterised in that said shut-off valve (36) is arranged at such a distance from said regulator valve (10) that it is arranged, with reference to the helmet of a diver, in a specular position to that of the quick blow-off valve of said helmet.