# Patent

## Title
Self-acting pressure drain valve

## Abstract

A self-acting pressure activated drain valve includes at least one inlet configured to receive a fluid. A drainage passage delivers the fluid to at least one outlet where the fluid is expelled. The self-acting pressure activated drain valve further includes a flexible diaphragm configured to operate in an open position and a closed position based on a pressure. The flexible diaphragm is normally biased in the open position such that fluid is delivered from the at least one inlet to the at least one outlet via the drainage passage. The pressure, however, initiates the closed position such that air is prevented from flowing through the drainage passage.

## Background
TECHNICAL FIELD
The present invention relates generally to fluid drainage valves, and more particularly, to a self-acting pressure activated drain valve.
BACKGROUND
Vehicles, such as commercial airline vehicles for example, include environmental control systems (ECSs) that operate to control pressure and environmental conditions for improving comfort of the passengers and crew. When ECSs are switched off and exposed to cool and humid ambient air conditions, the temperature differential between the ECS and the ambient air can cause water condensation, which after a period of time results in the accumulation of water (i.e., water pooling) at one or more locations of the ECS.
Conventional methods for preventing water pooling consist of drilling holes at various locations of the ECS where water typically accumulates. Although the drilled holes allow water to drain, the holes remain open at all times regardless as to whether the ECS is operating or switched off. Consequently, the drilled holes remain open during operation of the ECS which results in flow loss through the ECS. Consequently, the overall efficiency of the ECS is reduced while also causing an undesirable increase in fuel consumption of the aircraft. To reduce the flow loss, the drilled holes are typically sized as small as possible. When the drill holes are sized too small, however, debris (e.g., dust, dirt, etc.) can clog the holes and prevent water from properly draining from the ECS.
SUMMARY
According to a non-limiting embodiment, a self-acting pressure activated drain valve includes at least one inlet configured to receive a fluid. A drainage passage delivers the fluid to at least one outlet where the fluid is expelled. The self-acting pressure activated drain valve further includes a flexible diaphragm configured to operate in an open position and a closed position based only on a pressure. The flexible diaphragm is normally biased in the open position such that fluid is delivered from the at least one inlet to the at least one outlet via the drainage passage. The pressure, however, initiates the closed position such that air is prevented from flowing through the drainage passage.
According to another non-limiting embodiment, a method of draining fluid using a self-acting pressure activated drain valve comprises disposing a flexible diaphragm above a drainage passage, and interposing at least one inlet of the self-acting pressure activated drain valve between a flow path of the fluid and the drainage passage. The method includes biasing the flexible diaphragm in an open position when a first pressure surrounding the self-acting pressure activated drain valve is less than or equal to a second pressure within the drainage passage such that the fluid is delivered through the drainage passage. The method further includes collapsing the flexible diaphragm into a closed position that seals the first opening in response to the first pressure being greater than the second pressure.



BRIEF DESCRIPTION OF THE DRAWINGS
The subject matter which is regarded as the invention is particularly pointed out and distinctly claimed in the claims at the conclusion of the specification. The foregoing and other features, and advantages of the invention are apparent from the following detailed description taken in conjunction with the accompanying drawings in which:
FIG. 1A is a perspective view of a self-acting pressure activated drain valve according to a non-limiting embodiment;
FIG. 1B is a cross-sectional view of the self-acting pressure activated drain valve shown in FIG. 1A operating in an open position;
FIG. 1C illustrates fluid flowing through the self-acting pressure activated drain valve shown in FIGS. 1A-1B when operating in the open-position;
FIG. 2A illustrates a diaphragm of the self-acting pressure activated drain valve shown in FIG. 1A when operating in a closed position;
FIG. 2B is a cross-sectional view of the self-acting pressure activated drain valve shown in FIG. 2A;
FIG. 3A is a perspective view of a self-acting pressure activated drain valve according to another non-limiting embodiment;
FIG. 3B illustrates fluid flowing through the self-acting pressure activated drain valve shown in FIG. 3A when operating in the open-position;
FIG. 3C illustrates a diaphragm of the self-acting pressure activated drain valve shown in FIGS. 3A-3C when operating in a closed position; and
FIG. 4A is a first view of a self-acting pressure activated drain valve installed in an environmental control system according to a non-limiting embodiment; and
FIG. 4B is a second view of a self-acting pressure activated drain valve installed in an environmental control system taken along line A-A′ showing a fluid flowing through a drainage passage when operating in the open position according to a non-limiting embodiment.



DETAILED DESCRIPTION OF THE INVENTION
Various non-limiting embodiments of the invention provide a self-acting pressure drainage valve that requires no active control or input from a microcontroller and/or individual actuator. The self-acting pressure drainage valve can be disposed in a system that varies the surrounding pressure based on whether the system is operational or switched off. When the system is switched off (i.e., not operating), the self-acting pressure drainage valve is normally biased in an open position such that fluid (e.g., water) can be expelled through a drainage passage of the valve. When, however, the system is operational (i.e., switched on) the increased pressure induces the valve into a closed position. Accordingly, and drainage passage is sealed such that air leakage through drainage passage is prevented. In this manner, the pressure within ECS is maintained and the overall efficiency is improved. Since the drainage passage can be selectively closed, the diameter of the drainage passage can be sized greater than conventional drill holes without causing undesirable flow losses.
Referring now to FIG. 1A, a self-acting pressure drainage valve 100 (hereinafter referred to as a self-acting pressure valve 100) is illustrated according to a non-limiting embodiment. The self-acting pressure valve 100 includes a housing 102 having one or more outer walls 104 extending between an upper side 106 and a lower side 108. The housing 102 defines an inner cavity containing a drainage passage 110. The drainage passage 110 includes a first opening 112 and a second opening 114 disposed opposite the first opening 112. The outer wall 104 has one or more inlets 116 in fluid communication with the first opening 112, and the lower side 108 has at least one outlet 118 in fluid communication with the second opening 114. A rim 119 extends radially along a plane between the inlets 116 and the first opening 112. The rim 119 is configured to direct fluid along a flow path (i.e., the upper surface of the rim 119) that extends from each inlet 116 to the first opening 112. Thus, a plurality of flow paths is defined about the circumference of the rim 119. According to an embodiment, the drainage passage 110 extends perpendicular with respect to the flow paths (e.g., the rim 119). In this manner, the drainage passage 110 can be aligned parallel to the normal gravitational force such that fluid entering the first opening 112 falls downward through the drainage passage 110 and exits the self-acting pressure drainage valve 100 via the second opening 114.
The self-acting pressure valve 100 further includes a flexible diaphragm 120 supported by the upper side 106. The diaphragm 120 comprises various elastomer materials including, but not limited to silicone. The material of the diaphragm 120 can also be selected according to a temperature operating range at the location of the valve. For example, at locations where temperatures are low (e.g., −20 degrees), the diaphragm 120 can comprise unreinforced silicone. A locations where temperatures are moderate (e.g., 300 degrees), the diaphragm 120 can comprise silicone reinforced with, for example, polyester. A locations where temperatures are high (e.g., 500 degrees), the diaphragm 120 can comprise silicone reinforced with an aramid polymer. According to a non-limiting embodiment, the diaphragm 120 is disposed above the drainage passage 110 such that a clearance is defined between the diaphragm 120 and the rim 119. The diaphragm 120 is biased in an open position when a first pressure surrounding the self-acting pressure valve 100 is less than or equal to a second pressure within the drainage passage 110. When operating in the open position, the first opening 112 is exposed to the inlets 116. Accordingly, fluid entering one or more of the inlets 116 is directed to the first opening 112, and in turn travels through the drainage passage 110 where it is expelled via the second opening 114 (see FIG. 1C).
Turning now to FIGS. 2A-2B, the self-acting pressure valve 100 is shown operating in a closed position. The closed position is self-induced in response to the first pressure surrounding the self-acting pressure valve 100 being greater than the second pressure within the drainage passage 110, which in turn collapses the diaphragm 120. That is, the self-acting pressure valve 100 induces the closed position based solely on a pressure differential without requiring any electronics and/or actuators. When the diaphragm 120 collapses, the first opening 112 is sealed, thereby preventing fluid (e.g., water, air, etc.) from entering the drainage passage 110. When the pressure differential returns to conditions where the first pressure surrounding the self-acting pressure activated drain valve 100 is less than or equal to a second pressure within the drainage passage 110, the diaphragm 120 returns to its normal biased open position such that the first opening 112 is unsealed and fluid can again flow into the drainage passage 110.
Turning now to FIGS. 3A-3B, a self-acting pressure activated drain valve 200 is illustrated according to another non-limiting embodiment. The self-acting pressure valve 200 includes a housing 202 having an outer wall 204 extending between an upper side 206 and a lower side 208. The housing 202 defines an inner cavity containing a drainage passage 210. The drainage passage 210 includes a first opening 212 and a second opening 214 disposed opposite the first opening 212. The outer wall 204 has one or more inlets 216 formed at a single side of the outer wall 204. The inlet 216 is in fluid communication with the first opening 212, and the lower side 208 has at least one outlet 218 in fluid communication with the second opening 214. A solid rear portion 217 is formed opposite the inlet 216. The solid rear portion 217 prevents fluid from flowing therethrough and re-directs fluid towards the first opening 212. Accordingly, the self-acting pressure activated drain valve 200 acts as a unidirectional drain valve. A rim 219 extends along a plane between the inlet 216 and the first opening 212. The rim 219 is configured to direct fluid along a single flow path that extends from the inlet 216 and the first opening 212. According to an embodiment, the drainage passage 210 extends perpendicular with respect to the flow path (e.g., the rim 219). In this manner, the drainage passage 210 can be aligned parallel to normal gravitational force such that fluid entering the first opening 212 falls downward through the drainage passage 210 and exits the self-acting pressure drainage valve 200 via the second opening 214.
The self-acting pressure valve 200 further includes a flexible diaphragm 220 supported by the upper side 206. According to an embodiment, the diaphragm 220 includes a flexible cantilever portion 221 configured to open and close based on a pressure differential realized by the self-acting pressure drainage valve 200. The diaphragm 220 comprises various elastomer materials including, but not limited to, silicone. According to a non-limiting embodiment, the diaphragm 220 is disposed above the drainage passage 210 such that a clearance is defined between the diaphragm 220 and the rim 219. The diaphragm 220 is biased in an open position when a first pressure surrounding the self-acting pressure valve 200 is less than or equal to a second pressure within the drainage passage 210. When operating in the open position, the first opening 212 is exposed to the first inlet 216. Accordingly, fluid entering the inlet 216 is directed to the first opening 212, and in turn travels through drainage passage 210 where it is expelled via the second opening 214 (see FIG. 3B).
Turning now to FIG. 3C, the self-acting pressure drainage valve 200 is shown operating in a closed position. The closed position is self-induced in response to the first pressure surrounding the self-acting pressure valve 200 being greater than the second pressure within the drainage passage 210, which in turn collapses the cantilever portion 221 against the rim 219. That is, the self-acting pressure drainage valve 200 induces the closed position based solely on a pressure differential without requiring any electronics and/or actuators. When the cantilever portion 221 collapses, the inlet 216 is sealed, thereby preventing fluid (e.g., water, air, etc.) from entering the first opening 212. When the pressure differential returns to conditions where the first pressure surrounding the self-acting pressure activated drain valve 200 is less than or equal to a second pressure within the drainage passage 210, the cantilever portion 221 returns to its normal biased open position such that the inlet 216 is re-opened (i.e., unsealed) and fluid can flow into the first opening 212 and through the drainage passage 210.
Turning to FIGS. 4A-4B, an ECS 300 including a self-acting pressure valve 302 installed at a drainage location 304 of a duct 306 is shown according to a non-limiting embodiment. Although the self-acting pressure valve 302 is shown as being installed in a duct 306, it should be appreciated that the self-acting pressure valve 302 may be installed at one or more other locations of the ECS including, but not limited to, headers, manifolds rotating components, or other locations known and/or anticipated to accumulate water. According to an embodiment, the self-acting pressure valve 302 is installed such that at least one inlet 308 is positioned transverse with respect to the air flow path at which air flows (e.g., through the duct 306) when the ECS 300 is operated (i.e., switched on).
Still referring to FIGS. 4A-4B, the ECS 300 is shown after recently being shut off. Accordingly, airflow stops flowing through the duct 306 along the flow path, thereby reducing the pressure surrounding the self-acting pressure valve 302. That is, when the ECS system is shut off, the pressure within the duct 306 reaches ambient pressure. As result, a first pressure surrounding the self-acting pressure valve 302 becomes less than or equal to a second pressure within the drainage passage 310 such that the diaphragm 312 is biased in the open position and the inlet 308 (i.e., the drainage passage) is unsealed (i.e., open). As the temperature within the duct 306 decreases over time, water vapor contained in the air within the duct 306 condenses causing fluid (e.g. water) to accumulate at the drainage location 304. The accumulated water is collected by the inlet 308 and directed to the drainage passage 310, where it is expelled (i.e., drained) from the duct 306.
When the ECS 300 is returned to operation (not shown in FIGS. 4A-4B), air flowing through the duct 306 causes the first pressure surrounding the self-acting pressure activated drain valve 302 to be greater than the second pressure within the drainage passage 310. Accordingly, the diaphragm 312 is self-induced into the closed position and the inlet 308 (i.e., the drainage passage) is sealed (i.e., closed) as described in detail above. Since the drainage passage 310 is sealed, air leakage through the drainage path 310 is prevented thereby maintaining the pressure within the duct 306. In this manner, the overall efficiency of the ECS 300 is improved.
While the invention has been described in detail in connection with only a limited number of embodiments, it should be readily understood that the invention is not limited to such disclosed embodiments. Rather, the invention can be modified to incorporate any number of variations, alterations, substitutions or equivalent arrangements not heretofore described, but which are commensurate with the spirit and scope of the invention. Additionally, while various embodiments of the invention have been described, it is to be understood that aspects of the invention may include only some of the described embodiments. Accordingly, the invention is not to be seen as limited by the foregoing description, but is only limited by the scope of the appended claims.

## Claims

1. A self-acting pressure activated drain valve, comprising: a housing including an upper side, a lower side, and a rim between the upper side and the lower side, the upper side and the rim defining at least one inlet therebetween that is configured to receive a fluid; at least one outlet configured to expel the fluid; and a drainage passage surrounded completely by the housing and extending from the rim to the lower side, the drainage passage including a first opening in fluid communication with the at least one inlet and a second opening in fluid communication with the at least one outlet, the first opening interposed between the upper side and the second opening; and a flexible diaphragm supported at the upper side such that the at least one inlet is interposed between the rim and the flexible diaphragm, the flexible diaphragm configured to operate in an open position and a closed position based on a pressure, wherein the flexible diaphragm is normally biased in the open position such that fluid is delivered from the at least one inlet to the at least one outlet via the drainage passage wherein the diaphragm is configured to collapse into the drainage passage and beneath the rim when operating in the closed position to block the fluid from traveling between the first opening and the second opening, and wherein an upper surface of the rim defines a flow path extending from the inlet to the first opening, and wherein the upper surface of the rim is exposed to the fluid while in both the open position and the closed position.

2. The self-acting pressure activated drain valve of claim 1, wherein the diaphragm is configured to remain in the biased open position when a first pressure surrounding the self-acting pressure activated drain valve is less than or equal to a second pressure within the drainage passage, and is configured to collapse in response to the first pressure being greater than the second pressure.

3. The self-acting pressure activated drain valve of claim 2, wherein the housing defines an inner cavity containing the first opening.

4. The self-acting pressure activated drain valve of claim 3, wherein the diaphragm comprises an elastomer material.

5. The self-acting pressure activated drain valve of claim 4, wherein the drainage passage is perpendicular with respect to the at least one inlet.

6. The self-acting pressure activated drain valve of claim 5, wherein the housing has a cylindrical shape including an outer wall extending between the upper side and the lower side, and the at least one inlet includes a plurality of inlets formed in the outer wall.

7. The self-acting pressure activated drain valve of claim 6, wherein the upper side supports the diaphragm, and the first opening is surrounded by each inlet among the plurality of inlets.

8. The self-acting pressure activated drain valve of claim 7, wherein the diaphragm collapses into the inner cavity and seals the first opening when operating in the closed position.

9. A method of draining fluid using a self-acting pressure activated drain valve, the method comprising: surrounding a drainage passage completely by a housing and a rim; disposing a flexible diaphragm at an upper surface of the housing and above a drainage passage, flowing fluid through at least one inlet and along a flow path toward the drainage passage, the flow path defined by an upper surface of the rim that extends from the at least one inlet to a first opening defined by the drainage passage; biasing the flexible diaphragm in an open position when a first pressure surrounding the self-acting pressure activated drain valve is less than or equal to a second pressure within the drainage passage such that the fluid is delivered through the drainage passage; and collapsing the flexible diaphragm into the housing and into the drainage passage to invoke a closed position that seals the first opening in response to the first pressure being greater than the second pressure, wherein the upper surface of the rim is exposed to the fluid while the flexible diaphragm is collapsed.

10. The method of claim 9, wherein the drainage passage is perpendicular with respect to the at least one inlet.

11. The method of claim 10, wherein the diaphragm blocks airflow through the drainage passage when collapsed in the closed position.

12. The method of claim 11, wherein the diaphragm comprises an elastomer material.