# US 8,057,192 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 8,057,192 B2 - Document ID: US8057192B2 - Status: Granted - Kind: B2 - Application number: 12/362,619 - Filed: 2009-01-30 - Published: 2009-05-21 - Granted: 2011-11-15 - Earliest claimed: 2005-04-25 - Assignees: Spence Engineering Company - Inventors: George W. Page, Jr.; Dan Walter Cole - Web page: https://patentgrep.com/patent/US8057192B2 ## CPC - F04F 1/06: the fluid medium acting on the surface of the liquid to be pumped (F04F1/02 takes precedence) - Y10T 137/7371: Fluid pressure - 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)} - Y10T: TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION ## 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. An aperture in the primary piston and passages may also be provided to prevent build-up of gas pressures and maintain pressures in preselected regions within the pump at atmospheric pressures. ## Claims ### Claim 1 A condensate pump, comprising: a condensate reservoir having 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, the primary piston further including a vertical aperture extending from a first end of the piston to an opposite end of the piston, the opposite end in fluid communication with the condensate reservoir; 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 the primary piston further includes a plurality of rings forming a first outer diameter and a plurality of recesses having a second outer diameter, the second outer diameter being less than the first outer diameter. ### Claim 3 (depends on 2) The condensate pump of claim 2 wherein the primary piston further includes four rings, with three recesses extending between each pair of adjacent rings. ### Claim 4 (depends on 2) The condensate pump of claim 2 wherein the recesses form cavities when the primary piston is assembled into the primary cylinder. ### Claim 5 (depends on 4) The condensate pump of claim 4 further including a plurality of passages in communication with the pressure vent. ### Claim 6 (depends on 5) The condensate pump of claim 5 that includes three cavities and further includes two passages, a first passage that is in communication with a second end of the secondary cylinder and with the pressure vent through a first cavity when the primary piston is in a first position, while isolating a first end of the secondary cylinder from the pressure vent, thereby venting the second end of the secondary cylinder through the first cavity to the pressure vent, and a second passage that is in communication with the first end of the secondary cylinder and with the pressure vent through a second cavity when the primary piston is in a second position, while isolating the second end of the secondary cylinder from the pressure vent, thereby venting the first end of the secondary cylinder through the second cavity to the pressure vent. ### Claim 7 (depends on 1) The condensate pump of claim 1, wherein the pressure/vent valve is located exterior of the condensate reservoir while the primary piston that includes the vertical aperture extends into the condensate reservoir. ### Claim 8 (depends on 1) The condensate pump of claim 1, wherein the pressure/vent valve is located within the condensate reservoir. ### Claim 9 (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 10 (depends on 1) The condensate pump of claim 1, wherein the pressure/vent valve further includes the primary piston slidably supported in the 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, and wherein the secondary piston slides in the secondary cylinder responsive to a movement of the primary piston between the first and second positions. ### Claim 11 (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 location of the primary cylinder to a second end of the secondary cylinder. ### Claim 12 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 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, the primary piston further including a vertical aperture extending from a first end of the piston to an opposite end of the piston, the opposite end in fluid communication with the condensate reservoir; 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; 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. ### Claim 13 (depends on 12) The condensate pump of claim 12 wherein the primary piston further includes a plurality of rings forming a first outer diameter and a plurality of recesses having a second outer diameter, the second outer diameter being less than the first outer diameter. ### Claim 14 (depends on 13) The condensate pump of claim 13 wherein the primary piston further includes four rings, with three recesses extending between each pair of adjacent rings. ### Claim 15 (depends on 13) The condensate pump of claim 13 wherein the recesses form cavities when the primary piston is assembled into the primary cylinder. ### Claim 16 (depends on 15) The condensate pump of claim 15 further including a plurality of passages in communication with the pressure vent. ### Claim 17 (depends on 16) The condensate pump of claim 16 that includes three cavities and further includes two passages, a first passage that is in communication with a second end of the secondary cylinder and with the pressure vent through a first cavity when the primary piston is in a first position, while isolating a first end of the secondary cylinder from the pressure vent, thereby venting the second end of the secondary cylinder through the first cavity to the pressure vent, and a second passage that is in communication with the first end of the secondary cylinder and with the pressure vent through a second cavity when the primary piston is in a second position, while isolating the second end of the secondary cylinder from the pressure vent, thereby venting the first end of the secondary cylinder through the second cavity to the pressure vent. ### Claim 18 (depends on 12) The condensate pump of claim 12, wherein the pressure/vent valve is located exterior of the condensate reservoir while the primary piston that includes the vertical aperture extends into the condensate reservoir. ### Claim 19 (depends on 12) The condensate pump of claim 12, wherein the pressure/vent valve is located within the condensate reservoir. ### Claim 20 (depends on 12) The condensate pump of claim 12, wherein the pressure/vent valve further includes the primary piston slidably supported in the 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, and wherein the secondary piston slides in the secondary cylinder responsive to a movement of the primary piston between the first and second positions. ### Claim 21 (depends on 20) The condensate pump of claim 20, 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.