Pilot valve controlled positive and negative pressure relief valves

Patent metadata

Field	Value
Publication number	US-9435449-B2
Application number	US-201213440494-A
Country	US
Kind code	B2
Filing date	Apr 5, 2012
Priority date	Apr 5, 2012
Publication date	Sep 6, 2016
Grant date	Sep 6, 2016

Abstract

Concepts and technologies disclosed herein for relief valves (“relief valves”). A relief valve can include a flow path, a primary valve poppet that is urged or biased into a closed position by a tensioned spring, and a pilot valve in communication with a valve compartment of the relief valve. When an exterior space pressure overcomes the tensioned spring, the primary valve poppet can be overcome and pressure between an interior space and the exterior space can equalize, at least partially. When the pressure within the interior space increases beyond a defined threshold, which can be defined by a spring of the pilot valve, the pilot valve can open, the valve compartment can vent, and the tensioned spring again can be overcome and can open to allow at least partial equalization of pressures within the interior space and the exterior space.

First claim

I claim:

1. A fuel tank, comprising:
a relief valve that includes a valve body, the valve body being positioned within an interior space of the fuel tank and including a valve compartment being configured to provide a fluid pathway between the interior space of the fuel tank and an exterior space, the valve compartment comprising:
a primary valve poppet located within the valve compartment;
a poppet shaft connected to the primary valve poppet, at least a portion of the poppet shaft passing through a poppet shaft bore annulus, the poppet shaft bore annulus being configured to allow fluid flow between the interior space and the valve compartment; and
a pilot valve located in an opening into the valve compartment and within the interior space of the fuel tank such that one end of the pilot valve abuts the valve compartment and an opposing end of the pilot valve abuts the interior space of the fuel tank, a further opening into an ambient pressure sense line between the pilot valve and the exterior space,

wherein the relief valve is configured to at least partially relieve a positive and a negative pressure differential between the interior space and the exterior space.

2. The fuel tank of claim 1 , wherein the valve compartment and the exterior space via the ambient pressure sense line has a first flow rate that exceeds a second flow rate between the interior space and the valve compartment.

3. The fuel tank of claim 1 , wherein the pilot valve further comprises:
a pilot valve body;
a pilot valve poppet located within the pilot valve body and comprising the exposed end that is directly exposed to the interior space; and
a pilot valve spring located between at least a portion of the pilot valve poppet and at least a portion of the pilot valve body, the pilot valve spring being configured to urge the pilot valve poppet into a sealed position at which the opening is obstructed by a pilot valve seal attached to the pilot valve poppet.

4. The fuel tank of claim 1 , further comprising a primary valve poppet spring located within the valve compartment, the primary valve poppet spring being configured to bias the primary valve poppet into a sealed position at which the fluid pathway is obstructed.

5. The fuel tank of claim 1 , wherein the pilot valve is configured to open at a crack pressure, and wherein opening of the pilot valve allows fluid to flow between the valve compartment and the exterior space via the ambient pressure sense line.

6. The fuel tank of claim 2 , further comprising:
a valve seal between the primary valve poppet and at least a portion of a tank boundary of the fuel tank; and
a poppet seal between the primary valve poppet and at least a further portion of the tank boundary of the fuel tank, wherein the primary valve poppet comprises a portion exposed to the interior space via a flow path formed in the valve compartment.

7. The fuel tank of claim 1 , wherein the relief valve is configured to open when a pressure within the interior space exceeds a defined positive pressure threshold, and wherein the relief valve is further configured to open when a pressure within the interior space drops below a defined negative pressure threshold.

8. The fuel tank of claim 1 , wherein the relief valve is configured to increase force on the primary valve poppet when the pressure in the interior space increases until the pilot valve opens.

Assignees

• Shelly Mark Alan
• Boeing Co

Inventors

• Shelly Mark Alan

Classifications

• B60K2015/03296

  Pressure regulating valves · CPC title

• F16K17/10 Primary

  with auxiliary valve for fluid operation of the main valve · CPC title

• B60K15/03519

  Valve arrangements in the vent line · CPC title

• F16K17/196

  spring-loaded · CPC title

• Y10T137/7771

  Bi-directional flow valves · CPC title