Pressure Regulating Valve

A pressure regulating valve comprising:

• a valve housing defining an internal bore and having a valve inlet to receive fluid at a first pressure and a fluid outlet to return fluid to a pump;
• a sleeve surrounding a center axis and defined by an overall sleeve length extending from a first sleeve end to a second sleeve end, wherein the sleeve has a central sleeve bore extending from the first sleeve end to the second sleeve end;
• a piston received within the central sleeve bore and defined by an overall piston length extending from a first piston end to a second piston end, the piston having an outer surface comprising a sleeve contact surface that is defined by an outer diameter, and wherein the central sleeve bore has a first surface portion comprising a piston contact surface that is defined by a first inner diameter, wherein the piston contact surface is configured to slide against the sleeve contact surface;
• a spring assembly that biases the piston within the sleeve to a valve closed position, and wherein when the first pressure at the valve inlet is greater than a spring biasing load, the piston moves to a valve open position to return fluid to the pump via the valve outlet;
• and
• wherein a ratio of the first inner diameter of the sleeve to the outer diameter of the piston is between 0.99 and 1.01.

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 pressure regulating valve configured to regulate the pressure across the metering valve and return excess fuel not utilized by the metering valve to the fuel pump, wherein the pressure regulating valve comprises
• a valve housing defining an internal bore and having a valve inlet to receive fluid at a first pressure and a fluid outlet to return fluid to a pump;
• a sleeve surrounding a center axis and defined by an overall sleeve length extending from a first sleeve end to a second sleeve end, wherein the sleeve has a central sleeve bore extending from the first sleeve end to the second sleeve end;
• a piston received within the central sleeve bore and defined by an overall piston length extending from a first piston end to a second piston end, the piston having an outer surface comprising a sleeve contact surface that is defined by an outer diameter, and wherein the central sleeve bore has a first surface portion comprising a piston contact surface that is defined by a first inner diameter, wherein the piston contact surface is configured to slide against the sleeve contact surface;
• a spring assembly that biases the piston within the sleeve to a valve closed position, and wherein when the first pressure at the valve inlet is greater than a spring biasing load, the piston moves to a valve open position to return fluid to the pump via the valve outlet;
• and
• wherein a ratio of the first inner diameter of the sleeve to the outer diameter of the piston is between 0.99 and 1.01.

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

• removing at least one of a sleeve or a piston from a valve housing and replacing the removed one of the sleeve or piston with a replaced sleeve or piston, wherein the valve housing defines an internal bore and has a valve inlet to receive fluid at a first pressure and a valve outlet to return fluid to a pump, and wherein the sleeve surrounds a center axis and is defined by an overall sleeve length extending from a first sleeve end to a second sleeve end, wherein the sleeve has a central sleeve bore extending from the first sleeve end to the second sleeve end, and wherein the piston is received within the central sleeve bore and is defined by an overall piston length extending from a first piston end to a second piston end, the piston having an outer surface comprising a sleeve contact surface that is defined by an outer diameter, and wherein the central sleeve bore has a first surface portion comprising a piston contact surface that is defined by a first inner diameter, wherein the piston contact surface is configured to slide against the sleeve contact surface, and
• wherein if the piston is removed and replaced, the replaced piston has one or more of the following piston characteristics
• a ratio of the overall piston length to the outer diameter of the piston is between 0.96 and 1.00,
• wherein the piston body includes a plurality of recessed areas that are spaced circumferentially apart from each other about center axis, and wherein each recessed area is defined by a recess length and a recess width, and wherein a ratio of the recess length to the recess width is between 2.28 and 2.52,
• wherein each recess has a first edge defined by a first radius and a second edge that is axially spaced from the first edge and defined by a second radius, and wherein the first radius is between 0.275 inches and 0.400 inches, and wherein the second radius is between 0.275 inches and 0.400 inches,
• wherein if the sleeve is removed and replaced, the replaced sleeve has one or more of the following sleeve characteristics
• wherein a ratio of the overall sleeve length to the first inner diameter of the sleeve is between 3.51 and 3.63,
• wherein the sleeve body includes a first set of windows extending circumferentially about the center axis, wherein the central sleeve bore has a second surface portion at the first set of windows that is defined by a second inner diameter greater than the first inner diameter,
• wherein a ratio of the first inner diameter of the sleeve to the second inner diameter is between 0.77 and 0.82.
• wherein each window of the first set of windows is defined by a window width, and wherein a ratio of the window width to the second inner diameter of the sleeve is between 0.46 and 0.53.
• wherein a ratio of the overall sleeve length to the window width is between 5.50 and 6.06,
• wherein if the sleeve and piston assembly is removed and replaced, the replaced sleeve and piston assembly has one or more of the following sleeve and piston assembly characteristics
• wherein a ratio of the first inner diameter of the sleeve to the outer diameter of the piston is between 0.99 and 1.01,
• wherein a ratio of the overall sleeve length to the overall piston length is between 0.96 and 1.00,
• wherein the sleeve includes a first set of windows extending circumferentially about the center axis, wherein the central bore has a second surface portion at the first set of windows that is defined by a second inner diameter greater than the first inner diameter.