US-20260124480-A1 - UNIBODY AIR MAINTENANCE DEVICE FOR A DRY FIRE PROTECTION SYSTEM

US20260124480A1US 20260124480 A1US20260124480 A1US 20260124480A1US-20260124480-A1

Abstract

A unibody air maintenance device includes a body that is a single, integral component. The body has an inlet and an outlet. The inlet receives a pressurized gas and the outlet directs the pressurized gas to a dry fire protection system. A regulator is disposed within the body and maintains a pressure of the pressurized gas at a set pressure. A check valve is disposed within the body and opens to allow the pressurized gas to flow from the inlet towards the outlet and closes to prevent the pressurized gas from flowing from the outlet towards the inlet. A three-way valve is disposed within the body downstream of the inlet and upstream of the regulator. The three-way valve allows the pressurized gas to flow towards the regulator in a regulate position and to prevent the pressurized gas from flowing through the unibody air maintenance device in an off position.

Inventors

David Deurloo
Scott Hanson

Assignees

THE RELIABLE AUTOMATIC SPRINKLER CO. INC.

Dates

Publication Date: 20260507
Application Date: 20251106

Claims (20)

1 . A unibody air maintenance device for a dry fire protection system, the unibody air maintenance device comprising: a body that is a single, integral component, the body having an inlet and an outlet, the inlet being configured to receive a pressurized gas from a pressurized gas source and the outlet being configured to direct the pressurized gas to the dry fire protection system; a regulator disposed within the body and downstream of the inlet, the regulator being configured to maintain a pressure of the pressurized gas through the unibody air maintenance device at a set pressure; a check valve disposed within the body and downstream of the regulator, the check valve being configured to open to allow the pressurized gas to flow from the inlet towards the outlet and to close to prevent the pressurized gas from flowing from the outlet towards the inlet; and a three-way valve disposed within the body downstream of the inlet and upstream of the regulator, the three-way valve being configured to allow the pressurized gas to flow towards the regulator in a regulate position and to prevent the pressurized gas from flowing through the unibody air maintenance device in an off position.
2 . The unibody air maintenance device of claim 1 , wherein the three-way valve includes a valve actuator that is configured to actuate the three-way valve from the regulate position to the off position.
3 . The unibody air maintenance device of claim 1 , further comprising a bypass passage disposed within the body, downstream of the three-way valve and upstream of the check valve, wherein the three-way valve is configured to allow the pressurized gas through the bypass passage towards the outlet and to prevent the pressurized gas from flowing to the regulator in a bypass position.
4 . The unibody air maintenance device of claim 1 , further comprising a gauge configured to provide an indication of the pressure of the pressurized gas, wherein the gauge includes a gauge port disposed within the body downstream of the regulator and upstream of the check valve.
5 . The unibody air maintenance device of claim 1 , further comprising a strainer disposed within the body downstream of the three-way valve and upstream of the regulator, wherein the strainer is configured to collect solid particles or debris within the pressurized gas from the pressurized gas source.
6 . The unibody air maintenance device of claim 1 , further comprising a restriction orifice disposed within the body downstream of the regulator and upstream of the check valve, the restriction orifice being configured to reduce a flow rate of the pressurize gas through the restriction orifice and towards the outlet.
7 . The unibody air maintenance device of claim 6 , wherein a diameter of the restriction orifice is less than a diameter of the regulator.
8 . The unibody air maintenance device of claim 1 , wherein the regulator includes a regulator orifice and a diaphragm configured to open and to close the regulator orifice to maintain the pressure of pressurized air through the unibody air maintenance device at the set pressure.
9 . The unibody air maintenance device of claim 8 , wherein the regulator includes a regulator actuator, the diaphragm being coupled to the regulator actuator, and the regulator actuator being configured to actuate the diaphragm to open and to close the regulator orifice.
10 . The unibody air maintenance device of claim 8 , further comprising a strainer disposed within the body downstream of the three-way valve and upstream of the regulator, wherein a portion of the regulator is disposed within strainer.
11 . The unibody air maintenance device of claim 1 , wherein the three-way valve has a valve body and a valve passage, the valve body being configured to block the inlet in the off position, and the valve passage being configured to allow the pressurized gas to flow to the regulator in the regulate position.
12 . The unibody air maintenance device of claim 11 , wherein the valve passage includes a first port, a second port, and a third port, the first port being in fluid communication with the inlet and the second port being in fluid communication with the regulator in the regulate position such that the unibody air maintenance device is configured to regulate the pressure of the pressurized gas to the dry fire protection system in the regulate position.
13 . The unibody air maintenance device of claim 12 , wherein the second port is in fluid communication with the inlet, the third port is in fluid communication with the check valve, and the valve body blocks flow of the pressurized gas to the regulator in a bypass position such that the unibody air maintenance device is configured to bypass the regulator in the bypass position.
14 . A system comprising: a dry fire protection system configured to distribute water to a coverage area; a pressurized gas source configured to supply a pressurized gas to the dry fire protection system; a pressurized gas supply line configured to supply the pressurized gas from the pressurized gas source to the dry fire protection system; and a unibody air maintenance device fluidly coupled to the pressurized gas supply line, the unibody air maintenance device comprising: a body that is a single, integral component, the body having an inlet and an outlet, the inlet being configured to receive the pressurized gas from the pressurized gas source and the outlet being configured to direct the pressurized gas to the dry fire protection system; a regulator disposed within the body and downstream of the inlet, the regulator being configured to maintain a pressure of the pressurized gas through the unibody air maintenance device at a set pressure; a check valve disposed within the body and downstream of the regulator, the check valve being configured to open to allow the pressurized gas to flow from the inlet towards the outlet and to close to prevent the pressurized gas from flowing from the outlet towards the inlet; and a three-way valve disposed within the body downstream of the inlet and upstream of the regulator, the three-way valve being configured to allow the pressurized gas to flow towards the regulator in a regulate position and to prevent the pressurized gas from flowing through the unibody air maintenance device in an off position.
15 . The system of claim 14 , further comprising a bypass passage disposed within the body, downstream of the three-way valve and upstream of the check valve, wherein the three-way valve is configured to allow the pressurized gas through the bypass passage towards the outlet and to prevent the pressurized gas from flowing to the regulator in a bypass position.
16 . The system of claim 14 , further comprising a gauge configured to provide an indication of the pressure of the pressurized gas, wherein the gauge includes a gauge port disposed within the body downstream of the regulator and upstream of the check valve.
17 . The system of claim 14 , further comprising a strainer disposed within the body downstream of the three-way valve and upstream of the regulator, wherein the strainer is configured to collect solid particles or debris within the pressurized gas from the pressurized gas source.
18 . The system of claim 14 , further comprising a restriction orifice disposed within the body downstream of the regulator and upstream of the check valve, the restriction orifice being configured to reduce a flow rate of the pressurize gas through the restriction orifice and towards the outlet.
19 . The system of claim 14 , wherein the regulator includes a regulator orifice and a diaphragm configured to open and to close the regulator orifice to maintain the pressure of pressurized air through the unibody air maintenance device at the set pressure.
20 . The system of claim 19 , further comprising a strainer disposed within the body downstream of the three-way valve and upstream of the regulator, wherein a portion of the regulator is disposed within strainer.

Description

CROSS-REFERENCE TO RELATED APPLICATION This application claims priority to U.S. Provisional Application No. 63/717,316, filed Nov. 7, 2024, the entire contents of which is hereby incorporated by reference. FIELD OF THE INVENTION The present invention relates generally to dry fire protection systems, and, in particular, to a unibody air maintenance device for such systems. BACKGROUND Dry fire protection systems include sprinklers that are connected to piping that may be exposed to freezing conditions, such as in freezers, loading docks, or outdoor walkways. In dry fire protection systems, fluid supply pipes are positioned in a space in which fluid (e.g., water, fire protection fluid, etc.) in the fluid supply pipes are not subject to freezing. In the heated space, a valve, also referred to as a dry valve, is positioned to prevent the fluid from flowing to the sprinklers until there is a fire. In particular, the dry valve is held closed by a pressurized gas (e.g., compressed air, nitrogen, or the like) and prevents the fluid from flowing to the sprinklers. The sprinklers are attached to a pipe network filled with the pressurized gas, and the pipe network extends into a space in which the fluid would otherwise be subject to freezing. A sprinkler comprises a frame deflector assembly, an inlet end connected to a pipe network of a fire suppression system, a plug seal at the inlet end to prevent fluid from exiting the sprinkler, an actuating mechanism to maintain the plug seal, and a fluid dispersion mechanism or a deflector. In a dry fire protection system, the plug seal of many sprinklers maintains the pressurized gas in the system piping. When an elevated temperature occurs, a thermally responsive support element fails, releasing the plug seal to allow air from the pipes to flow out of the pipes into the protected area through the sprinkler. The pressurized gas in the system decays (e.g., the pressure decreases) to a point where the dry valve automatically actuates, allowing water to enter the pipes. The fluid flows through the entire pipe network until reaching the sprinkler that has lost its element/seal upon detection of heat. Once the fluid arrives at the sprinkler, fluid flows through the sprinkler waterway towards the sprinkler deflector and is ultimately distributed by the sprinkler deflector. In some embodiments, the dry valve is a pre-action valve that is controlled to open or to close by a controller. In particular, the controller receives a signal from a heat detector or a smoke detector and then sends an electrical signal to the pre-action valve to actuate the pre-action valve to open, allowing the fluid to enter the pipes. There are several methods to fill such dry fire protection systems with the pressurized gas. To fill such systems with the pressurized gas, specialized equipment is needed to ensure that the pressure of the gas within the system is maintained at a pressure that allows the system to function as designed. One way to accomplish a set gas pressure in a fire protection system is to use a regulator type air maintenance device (AMD). Typically, a regulator type AMD includes a reservoir of higher gas pressure maintained at a pressure above the fire suppression system designed gas pressure. The path of gas under the normal operation comes into the inlet of the AMD, routed through the regulator and a restriction orifice proceeding into the system. The restriction orifice is sized so that the flow rate of an open sprinkler is more than the AMD can supply, so that the system will lose pressure upon sprinkler activation, but the AMD will be able to keep up with small leaks that occur in the system. Generally, AMDs are manufactured, or are assembled, from off-the-shelf components. Current AMDs, however, include several components coupled together (e.g., by several threaded couplings) such that the regulator, the restriction orifice, and the valves are housed in separate components. Such AMDs are large, heavy, and prone to leaks due to the several threaded couplings, and are complex due to needing to actuate several valves to isolate certain components (e.g., the regulator, the restriction orifice, etc.) for maintenance. In addition to keeping the system supplied with the designed gas pressure, another function for current AMDs is a “Quick Fill” bypass. Systems must be able to be returned to service in thirty minutes or less. Filling the system through the regulator and the restriction orifice would take too long, so AMDs have a bypass that bypasses the regulator and the restriction orifice so that the system can be filled quickly. Current AMDs also include a check valve in the path of the gas under normal operation. Some AMDs utilize a combination restriction orifice check valve or some AMDs include a check valve in the design of the regulator. The check valve is included to ensure that the system would not activate immediately if the air supply were temporarily removed from service, for examp