Thermally operated valve for automatically modulating the flow of fluids

摘要

A valve for automatically modulating a flow of fluid. The valve includes a flexible flow adjustment member having a variable diameter passage therethrough and an outer surface and a shell surrounding at least a portion of the outer surface and creating a void between the shell and the outer surface. The shell is in contact with the flow of fluid. The valve further includes a thermally reactive material that expands when heated and contracts when cooled. The thermally reactive material is within the void and is in contact with the outer surface of the flexible flow adjustment member. The thermally reactive material exerts pressure on the flexible flow adjustment member in response to a heating of the thermally reactive material to cause the variable diameter passage to close and to relieve pressure thereon in response to a cooling of the thermally reactive material to permit the variable diameter passage to open. The flow of condensate is permitted to pass through the variable diameter passage at an average temperature that generally parallels the average temperature of saturated steam within the steam system within a range of about 0 to 40 percent. The average maximum temperature of condensate flow permitted to pass through the variable diameter passage differs from the average minimum temperature of condensate flow permitted to pass through the variable diameter passage by up to about 25 degrees Fahrenheit.