High pressure relief valve nozzle

A fuel supply system incorporating:

• a fuel pump having a pump inlet and a pump outlet, the pump inlet being in fluid communication with a fuel supply;
• a metering valve receiving fuel from the fuel pump and directing the fuel to a gas turbine engine;
• and
• a high pressure relief valve upstream of the metering valve and downstream of the pump inlet, the high pressure relief valve being configured to move to an open position once system pressure downstream of the pump outlet exceeds a predetermined pressure level such the fuel can be returned to the pump inlet via the high pressure relief valve, and wherein the high pressure relief valve comprises
• a valve housing defining an internal bore and having a valve inlet configured to be in fluid communication with a pump outlet;
• a closure sleeve at least partially received within the internal bore, the closure sleeve comprising a sleeve body surrounding a center axis, wherein the sleeve body has an internal cavity that is enclosed at a downstream end and open at an upstream end;
• a piston received within the internal cavity, wherein the internal cavity is defined in part by a piston contact surface that is defined by an inner diameter, wherein an outer surface of the piston slides against the piston contact surface;
• a nozzle received within the internal bore of the valve housing, the nozzle comprising a nozzle body surrounding a center axis and defined by an overall length extending from an inlet end to an outlet end, wherein the nozzle body has a nozzle bore defined by an outlet bore inner diameter at the outlet end and an inlet bore inner diameter at the inlet end, the inlet bore inner diameter being greater than the outlet bore inner diameter, and wherein the nozzle body has a nozzle face defined at the outlet end, the nozzle face being defined between the outlet bore inner diameter and an outlet bore outer diameter spaced radially outwardly of the outlet bore inner diameter, and wherein the nozzle body includes a coupling feature held fixed relative to the nozzle body such that the coupling feature is not moveable relative to the nozzle body, and wherein the coupling feature is configured to couple the nozzle body to the closure sleeve that surrounds the outlet end;
• at least one retaining feature that prevents the coupling feature from being uncoupled from the closure sleeve;
• a spring assembly that biases the piston to close the outlet end, and wherein when a system pressure at the outlet end exceeds a predetermined pressure level, a spring biasing load is overcome to open the nozzle outlet to fluidly connect the nozzle to the internal cavity of the closure sleeve;
• and
• wherein the nozzle includes one or more of the following nozzle characteristics
• wherein a ratio of the outlet bore inner bore diameter to the outlet bore outer diameter at the nozzle face is between 0.95 and 9.98,
• wherein a ratio of the outlet inner bore diameter at the nozzle face to the overall length is between 0.30 and 0.25,
• wherein the nozzle bore includes at least a first bore section defined by a first bore length and a generally constant bore diameter that corresponds to the outlet bore inner diameter, and wherein the nozzle bore includes a second bore section defined by a second bore length and a variable bore diameter, and wherein a ratio of the outlet bore inner diameter at the nozzle face to the first bore length is between 0.8 and 1.1, or
• wherein the second bore section increases in diameter along the second bore section length from an end of the first bore section to the inlet bore inner diameter such that the second bore section is defined by a conical surface angle, and wherein the conical surface angle of the nozzle is within a range between 0 degrees and 25 degrees.

A method of replacing a component in a high pressure relief valve including the steps of:

• removing a nozzle from a valve housing and replacing the removed nozzle with a replaced nozzle, wherein a closure sleeve is at least partially received within the valve housing and includes an internal cavity that is enclosed at a downstream end and open at an upstream end, a piston is received within the internal cavity of the closure sleeve, and wherein the nozzle comprises a nozzle body surrounding a center axis and defined by an overall length extending from an inlet end to an outlet end, wherein the nozzle body has a nozzle bore defined by an outlet bore inner diameter at the outlet end and an inlet bore inner diameter at the inlet end, the inlet bore inner diameter being greater than the outlet bore inner diameter, and wherein the nozzle body has a nozzle face defined at the outlet end, the nozzle face being defined between the outlet bore inner diameter and an outlet bore outer diameter spaced radially outwardly of the outlet bore inner diameter and wherein the nozzle body includes a coupling feature held fixed relative to the nozzle body such that the coupling feature is not moveable relative to the nozzle body, and wherein the coupling feature is configured to couple the nozzle body to the closure sleeve that surrounds the outlet end, and including at least one retaining feature that prevents the coupling feature from being uncoupled from the closure sleeve;
• and
• wherein if the nozzle is removed and replaced, the replaced nozzle has one or more of the following nozzle characteristics
• wherein a ratio of the outlet bore inner bore diameter to the outlet bore outer diameter at the nozzle face is between 0.95 and 9.98,
• wherein a ratio of the outlet inner bore diameter at the nozzle face to the overall length is between 0.30 and 0.25,
• wherein the nozzle bore includes at least a first bore section defined by a first bore length and a generally constant bore diameter that corresponds to the outlet bore inner diameter, and
• wherein the nozzle bore includes a second bore section defined by a second bore length and a variable bore diameter, and wherein a ratio of the outlet bore inner diameter at the nozzle face to the first bore length is between 0.8 and 1.1, or
• wherein the second bore section increases in diameter along the second bore section length from an end of the first bore section to the inlet bore inner diameter such that the second bore section is defined by a conical surface angle, and wherein the conical surface angle of the nozzle is within a range between 0 degrees and 25 degrees.