Pilot valve assembly

The present disclosure relates to an improved pilot valve assembly for a hydrant pit valve. The pilot valve assembly includes a poppet that is movable between an open position and a closed position. The poppet has a molded seal with an interlock feature to hold the seal rigidly. The pilot valve assembly also includes a manually reset mechanism. The reset mechanism can be horizontally positioned and can function to reset the pilot actuator for the next refueling operation. A lanyard can be connected to the poppet to be used a deactuation mechanism.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of Indian Provisional Patent Application No. 202111058968, filed Dec. 17, 2021. The disclosure of the priority application is hereby incorporated herein by reference in its entirety into the present application.

TECHNICAL FIELD

The present disclosure relates generally to hydrant valves or shut-off valves commonly used in aircraft fueling. More particularly, the present disclosure relates to a non-detachable pilot valve actuator.

BACKGROUND

Ground fueling hydrant pit valves are used for fueling aircrafts. The hydrant valves are typically installed in a hydrant pit below ground level to avoid collision with an aircraft or other vehicle. Hydrant valves are designed to deliver fuel by connecting fuel storage through an underground pipeline to an aircraft via a fueling vehicle equipped with a hydrant valve coupler and a hose system. Hydrant valves can be opened or closed by a fueling operator from a distance.

Hydrant valves are not controlled electromechanically due to concerns of fuel igniting. Pressure, either pneumatic or hydraulic, is typically utilized for controlling the opening and closing of hydrant valves. A quick disconnect pressure fitting can be used to apply the pneumatic or hydraulic pressure to the actuator. Due to the high pressure and flow rates sustained by hydrant valves, most hydrant valves are pilot operated. That is, the main hydrant valve can be opened or closed by actuating a smaller pilot valve installed in the main hydrant valve.

There is a need for a more improved pilot actuator assembly to enhance overall performance that results in less seal failure, contamination, and debris accumulation.

SUMMARY

The present disclosure relates to an improved pilot valve assembly for a hydrant pit valve. The pilot valve assembly is designed to block communication between a hydrant chamber and a piston chamber of the hydrant pit valve when a pilot valve of the pilot valve assembly is in a closed position. When air pressure is supplied, the pilot valve assembly can open the pilot valve against a biasing force to permit flow of fluid between the hydrant chamber and the piston chamber of the hydrant pit valve.

The pilot valve assembly includes a poppet that is movable between an open position and a closed position. The poppet has a molded seal with an interlock feature to hold the seal rigidly. An advantageous feature of the molded seal is the decreased risk of delamination which results in less contamination and debris accumulation in the pilot valve assembly. The poppet provides a seal when in the closed position.

The pilot valve assembly also includes a manually reset mechanism. The reset mechanism can be horizontally positioned and can function to reset the pilot actuator for the next refueling operation. The horizontal design of the reset mechanism can reduce the overall length of the pilot actuator assembly to help eliminate excessive loads on the pilot valve. The reset mechanism includes a projection that engages the poppet to restrict movement of the poppet when moved to the open position.

A lanyard can be connected to the poppet to be used a deactuation mechanism. When the lanyard is pulled, the poppet can be moved to an open position. A mechanical stop can be provided to restrict movement of the poppet connected to the lanyard. The mechanical stop may help to avoid excessive loading on the reset mechanism.

These and other features and advantages will be apparent from a reading of the following detailed description and a review of the associated drawings. A variety of additional aspects will be set forth in the description that follows. The aspects can relate to individual features and to combinations of features. It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the broad concepts upon which the examples disclosed herein are based.

DETAILED DESCRIPTION

The present disclosure relates to an improved pilot valve assembly. The advantageous features of the pilot valve assembly include a manual reset feature that includes a spring-loaded horizontal pin to reset the pilot actuator. The horizontal configuration of the reset mechanism reduces the overall dimensions of the pilot actuator assembly to decrease excessive loads on a pilot valve or valve stem of the assembly.

The pilot actuator assembly also has a new poppet sealing design that includes a molded type seal to help improve sealing performance and prevent contamination and debris accumulation in the pilot actuator assembly.

The pilot actuator assembly further includes a lanyard deactuation mechanism designed such that when pulled, a collar of the pilot actuator assembly defines a mechanical stop to limit movement of the poppet connected to the lanyard.

A typical hydrant pit valve may include three basic parts, a lower valve assembly, an upper valve assembly and a pilot valve.

FIG.1illustrates an example hydrant pit valve100that includes an upper valve assembly or hydrant body102. The hydrant body102defines a hydrant chamber104that has an inlet end106and an outlet end108. The hydrant body102has a flange110that defines openings112that can receive fasteners (not shown) for securing the hydrant body102to a flange114of a lower valve assembly (seeFIGS.2-3) of the hydrant pit valve100. A fuel supply (not shown) can be supplied to the hydrant chamber104through the inlet end106. A fueling vehicle (not shown) can receive fuel from the hydrant pit valve100through the outlet end108.

The hydrant body102may include a piston116within the hydrant chamber104that is movable between opened and closed positions relative to the inlet end106. The piston116defines a piston chamber118that can be in fluid communication with the inlet end106through a passageway120. When the piston116is in the closed position, it prevents the flow of fuel through the inlet end106. The piston chamber118can be isolated from the hydrant chamber104by seals122and124and a Z-pilot (i.e., dual pilot) valve126.

Because the piston chamber116can be in communication with the inlet end106, the pressure within the piston chamber116is equalized with the pressure at the inlet end106. In addition, because the piston chamber116can be isolated from the hydrant chamber104, the pressure in the hydrant chamber104is negligible. The piston114can remain in the closed position because of the equalized pressure exerted in the piston chamber116and the opposing pressure exerted at the inlet end106(see arrows).

Turning toFIGS.4-6, multiple views of the Z-pilot valve assembly assembly126are depicted. The Z-pilot valve assembly126includes a connector body128, a collar130with a connector flange132, an actuator body134, a pilot valve136and a lanyard138. The collar130can be mechanically attached to a distal end125(seeFIG.11) of the connector body128via the connector flange132using fasteners140. A mating portion133(seeFIG.11) of the actuator body134can be mounted to the connector body128at a proximal end127(seeFIG.11) of the connector body128. In certain examples, the actuator body134and the connector body128are formed together as one single piece, although alternatives are possible.

A pressure supply adapter142in the form of an elbow can be provided on the connector body128to connect a source of pressure medium, i.e., pneumatic, or hydraulic fluid. During normal operation, a minimum of 35 psi air pressure can be supplied through an inlet141of the pressure supply adapter142. The Z-pilot valve assembly126can also include a reset mechanism144(e.g., reset pin) that can be manually operated to reset the system. The reset mechanism144may be mounted within an opening143(seeFIG.11) defined in the collar130of the Z-pilot valve assembly126.

The Z-pilot valve assembly126can be mechanically secured to the hydrant pit valve100via one or more mounting plates146and fasteners148that may optionally include washers147. In the example depicted, two mating plates146are provided, although alternatives are possible. Each one of the mounting plates146may have a mating structure150configured to mate with a corresponding mating structure152on the actuator body134to provide a mating interface154. In certain examples, the mating interface154may provide an interference or friction fit connection. In certain examples, the fasteners148may be nylon insert bolts to help prevent rotation of the mounting plates146, although alternatives are possible. In some examples, the fasteners148include a hex bolt. In other examples, the fasteners148include socket head cap screws.

Turning toFIG.7, the pilot valve136can be disposed between the hydrant chamber104and the piston chamber118thereby blocking communication between the two chambers when the pilot valve136is in a closed position. The pilot valve136includes a pilot valve stem156, a pilot valve seat158, a pilot valve opening(s)160adjacent the pilot valve seat158, a pilot valve return spring162, and a pilot valve spring retainer164. The pilot valve return spring162biases the pilot valve stem156in a closed position against the pilot valve seat158. When the pilot valve stem156is positioned against the pilot valve seat158, fluid flow through the pilot valve opening(s)160can be obstructed. When the pilot valve stem156is moved away from the pilot valve seat158, the pilot valve136can move into an open position permitting the flow of fuel from the piston chamber118to the hydrant chamber104through the pilot valve opening(s)160.

The Z-pilot valve assembly126further includes a piston actuator166and a piston actuator return spring168housed within the actuator body134. The Z-pilot valve assembly126also includes a spring-loaded actuator poppet170(e.g., plunger) and an actuator poppet spring172. The piston actuator166is a non-detachable actuator (i.e., will remain secured to a pit valve). The piston actuator166can be sealed to prevent the transfer of pressure medium from the piston actuator166to the pilot valve136. The piston actuator166may have a generally T-shaped cross-section, although other shapes are possible that provide the same functions and results.

The piston actuator166has a rod section166aand a t-shaped section166bthat extends from two sides of the rod section166a. A neck section166cof the piston actuator166generally extends between the t-shaped section166band the rod section166c. The piston actuator return spring168is coiled about the rod section166aof the piston actuator166.

The actuator body134defines a cavity174that generally has a corresponding cross-sectional t-shape to receive the piston actuator166. Spring stops176are defined at a step portion178of the neck section166cand at a closed bottom180of the cavity174. The piston actuator166is movable between an extended or open position (seeFIG.9) and a retracted or closed position (seeFIG.7) within the cavity174of the actuator body134. The piston actuator return spring168is configured to bias the piston actuator166in the retracted or closed position. That is, in the absence of a pressure supply, the piston actuator return spring168biases the piston actuator166in a closed position.

FIGS.8-10illustrate a process of introducing a pressure medium through the pressure supply adapter142. When the pressure medium is introduced, a force can be exerted on the piston actuator166to move the piston actuator166to an extended or open position (seeFIG.9) against the biasing force of the piston actuator return spring168. When the piston actuator166is in the extended position, it engages the pilot valve stem156thereby moving the pilot valve136into an open position. That is, the piston actuator166provides actuating force to the pilot valve stem156to open the pilot valve stem156and move the pilot valve stem156away from the pilot valve seat158permitting the flow of fuel from the piston chamber116to the hydrant chamber104through the pilot valve opening(s)160. In this way, fuel is permitted to move from the inlet end106through the hydrant chamber104to the outlet end108. When the pressure medium is not supplied, as depicted inFIG.10, the piston actuator return spring168will bring the piston actuator166back to its original position to close the pilot valve stem156and the pilot valve return spring162again biases the pilot valve stem156against the pilot valve seat158closing the pilot valve136and the hydrant pit valve100.

FIGS.11-14will be used to describe the deactuation mechanism of the Z-pilot valve assembly126.

The lanyard138includes a cable180that can be looped through an opening182defined in the spring-loaded actuator poppet170adjacent a distal end184thereof. Sleeves186can be used to secure ends188of the cable180by a crimping method, although alternatives are possible. As shown inFIG.20, a cover310can be mounted to the connector128to cover the secured ends188of the cable180. In certain implementations, the cover310extends over all or a portion of the collar130. In certain examples, the cover310can be fastened or otherwise secured to the connector body128through the collar130. The cover310defines a guide surface312along which the cable180extends out of the cover310. In certain examples, the guide surface312has a funnel or trumpet shape.

The spring-loaded actuator poppet170includes a main body portion190, a head portion192and a recess194(e.g., cutout) defined in the main body portion190. The spring-loaded actuator poppet170can be formed from a mold and include a plurality of holes196in the head portion192. The main body portion190and the head portion192can be formed as one-piece, single body.

An end face198of the head portion192of the spring-loaded actuator poppet170can be provided with a seal member200and the seal member200can also be disposed within the holes196of the head portion192. The advantageous feature of having the seal member200formed in the holes196of the head portion192is to add structural integrity to eliminate the risk of delamination of the seal member200from the end face198. That is, the seal member200in the holes196provides an interlock feature to hold the seal rigidly to eliminate delamination from the end face198of the head portion192.

An O-ring202can be used to seal the spring-loaded actuator poppet170from an opposite top side. The O-ring202can help to prevent dust, debris, and/or water from entering into a sliding location204defined in the collar130where the spring-loaded actuator poppet170is slidably movable and/or into the connector body128.

Actuating pressure can be vented through a vent hole206defined in the connector body128. In the example depicted, the vent hole204is configured to help avoid accumulation of dust, water and/or debris. The vent hole206and the inlet141are both sealed by the seal member200of the spring-loaded actuator poppet170.

Turning toFIGS.15-16, the lanyard138is designed to provide a deactuation mechanism in case of emergency. When the lanyard138is pulled in the first direction D1, the spring-loaded actuator poppet170is lifted to bias against the actuator poppet spring172allowing air pressure to pass through connector body flow passages208and vent through the vent hole204out into the atmosphere such that the hydrant pit valve100closes.

The collar130has a mechanical stop210that limits the range of motion of the spring-loaded actuator poppet170when lifted by the lanyard138. The spring-loaded actuator poppet170can be pulled by the lanyard138until the reset mechanism144engages the recess194of the spring-loaded actuator poppet170.

The reset mechanism144may include a split pin212aor knob212bthat is attached to a rest pin214. In certain examples, the split pin212can be attached to the reset pin214via an opening of the reset pin214. In certain examples, the knob212bmay be threadedly attached (see214a) to the reset pin214. In the example depicted, the reset pin214is configured in a horizontal position, which is advantageous in reducing the overall length of the Z-pilot valve assembly126. As such, excessive loads on the pilot valve stem156can be reduced.

The reset pin214can be a spring-loaded pin that is slidably movable within a housing213(seeFIG.11). The reset pin214includes a projection216that engages the spring-loaded actuator poppet. When the spring-loaded actuator poppet170is in a closed position thereby creating a seal for the vent hole204and the inlet141, the reset pin214is in a first position as shown inFIG.11prior to pulling the lanyard138. The projection216of the reset pin214can be biased against the main body portion190of the spring-loaded actuator poppet170. When the lanyard138is pulled, the spring-loaded actuator poppet170can be biased against the actuator poppet spring172. The spring-loaded actuator poppet170can be lifted to allow the projection216to pop into the recess194of the spring-loaded actuator poppet170to restrict the motion of the spring-loaded actuator poppet170. The reset pin214is then locked in the recess194in a second position (seeFIG.15) until the reset mechanism144is reset. The head portion192can engage the mechanical stop210of the collar130to avoid adding excessive loading on the pin214when the lanyard138is pulled. Lack of air pressure on the pilot valve136can bias the piston actuator166against spring load to its retracted or closed position which closes the hydrant pit valve100.

Turning toFIG.16, the split pin212aor knob212bcan be used to manually reset operation of the Z-pilot valve assembly126. For example, the split pin212acan be used to manually pull the reset pin214of the reset mechanism144in a second direction D2—to ready for its next use. The projection216of the reset pin214can be removed from the recess194to release the spring-loaded actuator poppet170which is allowed to close due to a spring load. The spring-loaded actuator poppet170seals and closes the vent hole204to allow for the next refueling operation.

In some examples, the reset pin214has a cylindrical shape. In other examples, the reset pin214has one or more radially outwardly-facing flat surfaces215. In certain examples, the reset pin214defines two oppositely facing flat surfaces215. The one or more flat surfaces215enhance the ability of a tool such as a wrench gripping the reset pin214to facilitate assembly or disassembly of the knob212b.

In some implementation, the actuator body134is threadably mounted to the connector body128. In other implementations, however, the actuator body134is snap fit, friction fit, or otherwise secured to the connector body128. Referring toFIGS.17-19, the actuator body134and the connector body128are configured to inhibit relative rotation along a longitudinal axis A of the actuator body134. In certain implementations, the actuator body134and connector body128each define one or more flat surfaces that abut each other to inhibit rotation.

For example, as shown inFIG.17, the actuator body134(e.g., the mating portion133of the actuator body134) includes a radially outwardly-facing flat surface300and the connector body128defines a radially inwardly-facing flat surface302. When the actuator body134is mounted at the connector128, the outwardly-facing flat surface300contacts the inwardly-facing flat surface302to inhibit the actuator body134from rotating about the axis A relative to the connector128. In some examples, the actuator body134and connector body128include only a single flat surface300,302each so that the actuator body134can be mounted at the connector body128in only one rotational position. In other examples, however, one or both of the actuator body134and the connector body128may include multiple flat surfaces to enable mounting in various rotational positions, but to retain in a single rotational position once mounted.

In certain implementations, the actuator body134also is configured to inhibit rotation relative to the mounting plate146. For example, as shown inFIG.17, the actuator body134may include a second set of one or more flat surfaces304configured to align with one or more flat surfaces defined by the mounting plate146. In certain examples, the flat surfaces304are spaced from the flat surface302along the axis A of the actuator body134. In certain examples, the flat surfaces304are radially spaced from the flat surface302. In the example shown, the actuator body134defines a single flat surface302to engage with the connector body128and multiple flat surfaces304to engage with the mounting plate146.

The principles, techniques, and features described herein can be applied in a variety of systems, and there is no requirement that all of the advantageous features identified be incorporated in an assembly, system or component to obtain some benefit according to the present disclosure.

From the forgoing detailed description, it will be evident that modifications and variations can be made without departing from the spirit and scope of the disclosure.