Fluid flow restrictor device

A fluid flow restrictor device for controlling fluid flow at a connection between a first duct and a second duct, the fluid flow restrictor device comprising:

• a restrictor device body having an outboard end, an inboard end that is inserted into and disposed within the first duct when the fluid flow restrictor device is installed at the connection, a body inner surface defining a restrictor opening through the restrictor device body from the outboard end to the inboard end, and a body outer surface;
• and
• an outboard restrictor device flange extending radially outward at the outboard end of the restrictor device body and having an outboard flange outer diameter that is greater than a first duct inner diameter of the first duct so that the outboard restrictor device flange is engaged by a first duct open end surface of the first duct to prevent full insertion of the fluid flow restrictor device into the first duct when the fluid flow restrictor device is installed at the connection;
• wherein a body inner diameter of the restrictor device body decreases from a maximum body inner diameter at the outboard end as the body inner surface extends from the outboard end toward the inboard end until the body inner diameter is equal to a minimum body inner diameter;
• and
• wherein, when the body inner surface is viewed in cross-section taken through a plane that is parallel to a body longitudinal axis of the restrictor device body and has the body longitudinal axis lying within the plane, the body inner surface has a constant radius of curvature as the body inner surface extends from the outboard end toward the inboard end.

A fluid flow system, comprising:

• a first duct having a first duct inner surface with a first duct inner diameter and a first duct open end surface;
• a second duct having a second duct inner surface with a second duct inner diameter and a second duct open end surface;
• a fluid flow restrictor device comprising:
• a restrictor device body having an outboard end, an inboard end, a body inner surface defining a restrictor opening through the restrictor device body from the outboard end to the inboard end, and a body outer surface, and
• an outboard restrictor device flange extending radially outward at the outboard end of the restrictor device body and having an outboard flange outer diameter that is greater than the first duct inner diameter, wherein the inboard end is inserted into the first duct until the outboard restrictor device flange is engaged by the first duct open end surface to prevent full insertion of the fluid flow restrictor device into the first duct;
• a duct connection mechanism engaging the first duct and the second duct to substantially prevent relative movement between the first duct and the second duct and to retain the fluid flow restrictor device installed within the first duct;
• and
• an alignment ring having an annular shape, an alignment ring inner diameter that is greater than a body outer diameter, and an alignment ring outer diameter that is greater than the first duct inner diameter, wherein the alignment ring is disposed on the body outer surface and between the outboard restrictor device flange and the first duct open end surface.

A method of controlling fluid flow at a connection between a first duct and a second duct, comprising

• inserting an inboard end of a restrictor device body of a fluid flow restrictor device through a first duct open end surface and into the first duct, wherein a portion of the fluid flow restrictor device has an outer diameter that is greater than a first duct inner diameter of a first duct inner surface so that the portion of the fluid flow restrictor device wherein a body outer surface of the restrictor device body is tapered such that a body outer diameter decreases from a maximum body outer diameter proximate the outboard end to a minimum body outer diameter proximate the inboard end, wherein the maximum body outer diameter is greater than the first duct inner diameter and the minimum body outer diameter is less than the first duct inner diameter, and wherein the portion of the fluid flow restrictor device is a location on the body outer surface at which the body outer diameter is equal to the first duct inner diameter and is engaged by an edge at an intersection of the first duct inner surface and the first duct open end surface is engaged by the first duct to prevent an outboard end of the fluid flow restrictor device from being completely inserted into the first duct, and wherein the restrictor device body has a body inner surface extending through the restrictor device body from the outboard end to the inboard end and defining a restrictor opening through the fluid flow restrictor device;
• contacting the outboard end of the fluid flow restrictor device with a second duct open end surface of the second duct;
• and
• engaging the first duct and the second duct with a duct connection mechanism to substantially prevent relative movement between the first duct and the second duct and to form a seal between the first duct, the second duct and the fluid flow restrictor device.