# US 7,491,035 B2 · Cyclic condensate pump having a three-way valve > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 7,491,035 B2 - Document ID: US7491035B2 - Status: Granted - Kind: B2 - Application number: 11/113,593 - Filed: 2005-04-25 - Published: 2006-10-26 - Granted: 2009-02-17 - Earliest claimed: 2005-04-25 - Assignees: Spence Engineering Company - Inventors: George W. Page, Jr.; Dan Walter Cole - Web page: https://patentgrep.com/patent/US7491035B2 ## CPC - F04F 1/06: the fluid medium acting on the surface of the liquid to be pumped (F04F1/02 takes precedence) - F04F: PUMPING OF FLUID BY DIRECT CONTACT OF ANOTHER FLUID OR BY USING INERTIA OF FLUID TO BE PUMPED {(evacuating by sorption F04B)}; SIPHONS {(conveying materials in bulk by flows of gas, liquid of foam B65G53/00)} ## Abstract A condensate pump includes a condensate reservoir, a liquid level float sensor operable to sense a liquid level within the condensate reservoir, and a pressure/vent valve including a pressure source, a pressure vent, and a primary piston slidably supported in a primary cylinder and sliding in the primary cylinder responsive to the liquid level sensor. A secondary piston is slidably supported in a secondary cylinder and moves responsive to a movement of the primary piston between a first secondary-piston position wherein the pressure source is in communication with a gas space of the condensate reservoir and the pressure vent is isolated from the gas space, and a second secondary-piston position wherein the pressure source is isolated from the gas space and the pressure vent is in communication with the gas space. ## Claims ### Claim 1 A condensate pump, comprising: a condensate reservoir comprising a fluid inlet, an inlet check valve operable to prevent a flow of fluid out of the condensate reservoir through the fluid inlet and to allow a flow of fluid into the condensate reservoir through the fluid inlet, a fluid outlet, and an outlet check valve operable to prevent a flow of fluid into the condensate reservoir through the fluid outlet and to allow a flow of fluid out of the condensate reservoir through the fluid outlet; a liquid level sensor operable to sense a liquid level within the condensate reservoir; and a pressure/vent valve further comprising a primary piston slidably supported in a primary cylinder, wherein the primary piston slides in the primary cylinder responsive to the liquid level sensor, between a first primary piston position and a second primary piston position, a pressure source, a pressure vent, a three-way valve further comprising a secondary piston slidably supported in a secondary cylinder, wherein the secondary piston slides in the secondary cylinder between a first secondary piston position in which the pressure source is in communication with a gas space of the condensate reservoir and the pressure vent is isolated from the gas space, and a second secondary piston position in which the pressure source is isolated from the gas space and the pressure vent is in communication with the gas space, and wherein the movement of the secondary piston in the secondary cylinder is responsive to movement of the primary piston in the primary cylinder. ### Claim 2 (depends on 1) The condensate pump of claim 1, wherein when the secondary piston is in the first three-way-valve position the pressure vent is isolated from the gas space, when the secondary piston is in the second three-way-valve position the pressure source is isolated from the gas space. ### Claim 3 (depends on 1) The condensate pump of claim 1, wherein the pressure/vent valve is located exterior to the condensate reservoir. ### Claim 4 (depends on 1) The condensate pump of claim 1, wherein the pressure/vent valve is located within the condensate reservoir. ### Claim 5 (depends on 1) The condensate pump of claim 1, wherein the secondary piston is double ended in a secondary piston spool configuration. ### Claim 6 (depends on 1) The condensate pump of claim 1, further including a reservoir pressurization line extending from the pressure source to a first intermediate location of the secondary cylinder, a reservoir vent line extending from the vent to a second intermediate location of the secondary cylinder, and a pressurization/vent line extending from a third intermediate location of the secondary cylinder to the gas space of the condensate reservoir. ### Claim 7 (depends on 1) The condensate pump of claim 1, wherein the primary piston is double ended in a primary piston spool configuration. ### Claim 8 (depends on 1) The condensate pump of claim 1, wherein the liquid level sensor comprises a float within the condensate reservoir, and an actuating arm connected to the float and movable with the float, and wherein the actuating arm is connected to the primary piston. ### Claim 9 (depends on 1) The condensate pump of claim 1, further including a main pressure drive line extending from the pressure source to an intermediate location of the primary cylinder, a first branch pressure drive line extending from a first intermediate location of the primary cylinder to a first end of the secondary cylinder, and a second branch pressure drive line extending from a second intermediate location of the primary cylinder to a second end of the secondary cylinder. ### Claim 10 A condensate pump, comprising: a condensate reservoir comprising a fluid inlet, an inlet check valve operable to prevent a flow of fluid out of the condensate reservoir through the fluid inlet and to allow a flow of fluid into the condensate reservoir through the fluid inlet, a fluid outlet, and an outlet check valve operable to prevent a flow of fluid into the condensate reservoir through the fluid outlet and to allow a flow of fluid out of the condensate reservoir through the fluid outlet; a liquid level sensor operable to sense a liquid level within the condensate reservoir, wherein the liquid level sensor comprises a float within the condensate reservoir, and an actuating arm connected to the float and movable with the float; and a pressure/vent valve comprising a pressure source, a pressure vent, a primary piston slidably supported in a primary cylinder, wherein the primary piston slides in the primary cylinder responsive to the liquid level sensor, between a first primary piston and a second primary piston position, and wherein the actuating arm is connected to the primary piston, a secondary piston slidably supported in a secondary cylinder, wherein the secondary piston slides in the secondary cylinder responsive to a movement of the primary piston, between a first secondary piston position wherein the pressure source is in communication with a gas space of the condensate reservoir and the pressure vent is isolated from the gas space, and a secondary piston position wherein the pressure source is isolated from the gas space and the pressure vent is in communication with the gas space. ### Claim 11 (depends on 10) The condensate pump of claim 10, wherein the pressure/vent valve is located exterior to the condensate reservoir. ### Claim 12 (depends on 10) The condensate pump of claim 10, wherein the pressure/vent valve is located within the condensate reservoir. ### Claim 13 (depends on 10) The condensate pump of claim 10, wherein the primary piston is double ended in a primary piston spool configuration and the secondary piston is double ended in a secondary piston spool configuration. ### Claim 14 (depends on 10) The condensate pump of claim 10, further including a main pressure drive line extending from the pressure source to an intermediate location of the primary cylinder, a first branch pressure drive line extending from a first intermediate location of the primary cylinder to a first end of the secondary cylinder, and a second branch pressure drive line extending from a second intermediate position of the primary cylinder to a second end of the secondary cylinder. ### Claim 15 (depends on 10) The condensate pump of claim 10, further including a reservoir pressurization line extending from the pressure source to a first intermediate location of the secondary cylinder, a reservoir vent line extending from the vent to a second intermediate location of the secondary cylinder, and a pressurization/vent line extending from a third intermediate location of the secondary cylinder to the gas space of the condensate reservoir. ### Claim 16 A condensate pump, comprising: a condensate reservoir comprising a fluid inlet, an inlet check valve operable to prevent a flow of fluid out of the condensate reservoir through the fluid inlet and to allow a flow of fluid into the condensate reservoir through the fluid inlet, a fluid outlet, and an outlet check valve operable to prevent a flow of fluid into the condensate reservoir through the fluid outlet and to allow a flow of fluid out of the condensate reservoir through the fluid outlet; a liquid level sensor operable to sense a liquid level within the condensate reservoir, wherein the liquid level sensor comprises a float within the condensate reservoir, and an actuating arm connected to the float and movable with the float; a pressure/vent valve located exterior to the condensate reservoir and comprising a pressure source, a pressure vent, a primary piston slidably supported in a primary cylinder, wherein the primary piston is double ended in a primary piston spool configuration, wherein the primary piston slides in the primary cylinder responsive to the liquid level sensor, between a first primary piston position and a second primary piston position, and wherein the actuating arm is connected to the primary piston, and a secondary piston slidably supported in a secondary cylinder, wherein the secondary piston is double ended in a secondary piston spool configuration, and wherein the secondary piston slides in the secondary cylinder between a first secondary piston position wherein the pressure source is in communication with a gas space of the condensate reservoir and the pressure vent is isolated from the gas space, and a second secondary piston position wherein the pressure source is isolated from the gas space and the pressure vent is in communication with the gas space; a drive pressurization structure including a main pressure drive line extending from the pressure source to an intermediate location of the primary cylinder, a first branch pressure drive line extending from a first intermediate location of the primary cylinder to a first end of the secondary cylinder, and a second branch pressure drive line extending from a second intermediate location of the primary cylinder to a second end of the secondary cylinder; and a reservoir pressurization/vent structure including a reservoir pressurization line extending from the pressure source to a first intermediate location of the secondary cylinder, a reservoir vent line extending from the vent to a second intermediate location of the secondary cylinder, and a pressurization/vent line extending from a third intermediate location of the secondary cylinder to the gas space of the condensate reservoir.