Overfill prevention valve for shallow tanks

• US 7,584,766 B2
• Filed: 03/07/2006
• Issued: 09/08/2009
• Est. Priority Date: 03/07/2006
• Status: Active Grant

• Current Assignee: Clay & Bailey Manufacturing Company
• Original Assignee: Clay & Bailey Manufacturing Company
• Inventors: David, Donald R., Borst, Ronald W.
• Primary Examiner(s): Rivell; John
• Assistant Examiner(s): PRICE, CRAIG JAMES
• Application Number:
  US11/369,253
• Publication Number:
  US 20070209713A1
• Time in Patent Office: 1,281 Days
• Field of Search: 137412-414, 137/423, 137/429, 137/430, 137/432, 137/433, 141/98, 141/95, 141/141, 141/198
• US Class Current: 137/413
• CPC Class Codes: F16K 31/18 actuated by a float floats F16K33/00; float-actuated valves in steam-traps F16T1/20, in boilers F22D5/08
• CPC Class Codes: F16K 31/34 acting on pilot valve controlling the cut-off apparatus
• CPC Class Codes: F16K 33/00 Floats for actuation of valves or other apparatus float actuated valves F16K31/18
• CPC Class Codes: Y10T 137/7368 Servo relay operation of control
• CPC Class Codes: Y10T 137/7371 Fluid pressure
• CPC Class Codes: Y10T 137/7436 Float rigid with valve

Abstract

An overfill prevention valve for mounting on the filling inlet of a liquid storage tank has an elongated, tubular valve body provided with an inlet at one end and one or more outlets in the sidewall thereof. A pressure-actuated piston is moveable between an open position spaced below an annular valve seat between the inlet and outlets and a closed position engaging the valve seat to close the outlet. An orifice in the top of the piston communicates with an actuating chamber on the opposite side of the piston so that a measure of piloting liquid flows into the chamber and out a pilot hole at the bottom of the valve body during normal filling operations. A buoyant float is slidable along a hollow guide tube attached to the bottom of valve body and communicates with the pilot port for closing a discharge hole in the guide tube when the float rises to an upwardly buoyed position due to the liquid in the tank reaching a predetermined maximum level. Such closure of the discharge hole causes the pressure within the chamber to rise, shifting the piston to its upper, closed position against the valve seat, thereby closing the outlets and terminating further flow into the tank.

Claims

1. An overfill prevention valve for mounting on a liquid storage tank comprising:

an elongated hollow valve body having an inlet at one end adapted for connection to a source of supply of liquid under pressure for filling the tank, at least one laterally disposed outlet downstream from said inlet for delivering liquid into the tank from the body, a valve seat between the inlet and the outlet, and a pilot port at an opposite end of the body;

a piston axially movable within said body between an open position wherein the piston is spaced away from said seat to permit incoming liquid to flow through the outlet and into the tank and a closed position wherein the piston is sealingly engaged with said seat to prevent liquid flow through the outlet and into the tank,

said piston cooperating with said opposite end of the body to define an expandable actuating chamber that communicates with said pilot port,

said piston having an orifice disposed for communicating the chamber with the inlet so that the chamber receives piloting liquid from the flow entering the body;

a guide tube fixed to and projecting downwardly from said opposite end of the body and communicating with said pilot port,

said guide tube having a discharge hole at a location spaced below the body for permitting piloting liquid to escape from the chamber into the tank via the pilot port, the guide tube, and the discharge hole; and

a float buoyantly shiftable along and relative to said tube between a lower position uncovering said discharge hole when liquid within the tank is below a predetermined maximum level and an upwardly buoyed position covering said discharge hole when liquid reaches said predetermined maximum level,

said float being adapted when in said upwardly buoyed position for causing piloting liquid pressure to increase in the chamber and shift the piston from the open position to the closed position.

2. An overfill prevention valve as claimed in claim 1,

said piston having a generally tapered nose facing in the upstream direction,

said nose being disposed to engage said seat when the piston is in the closed position and to direct liquid toward said outlet when the piston is in the open position.

3. An overfill prevention valve as claimed in claim 2,

said nose having an uppermost, central tip,

said orifice being disposed at said tip.

7. An overfill prevention valve as claimed in claim 1,

further comprising a coupling neck secured to said one end of the valve body and having an enlarged, internally threaded annular skirt adapted for attaching the neck to the externally threaded upper end of a fitting on a storage tank,

said coupling neck having an internally threaded bore spaced radially inwardly from said skirt,

said one end of the valve body being externally threaded and threadably received by said bore.

4. An overfill prevention valve for mounting on a liquid storage tank comprising:

an elongated hollow valve body having an inlet at one end adapted for connection to a source of supply of liquid under pressure for filling the tank, at least one laterally disposed outlet downstream from said inlet for delivering liquid into the tank from the body, a valve seat between the inlet and the outlet, and a pilot port at an opposite end of the body;

a piston axially movable within said body between an open position wherein the piston is spaced away from said seat to permit incoming liquid to flow through the outlet and into the tank and a closed position wherein the piston is sealingly engaged with said seat to prevent liquid flow through the outlet and into the tank,

said piston cooperating with said opposite end of the body to define an expandable actuating chamber that communicates with said pilot port,

said piston having an orifice disposed for communicating the chamber with the inlet so that the chamber receives piloting liquid from the flow entering the body;

a guide tube fixed to and projecting downwardly from said opposite end of the body and communicating with said pilot port,

said guide tube having a discharge hole at a location spaced below the body for permitting piloting liquid to escape from the chamber into the tank via the pilot port, the guide tube, and the discharge hole; and

a float buoyantly shiftable along and relative to said tube between a lower position uncovering said discharge hole when liquid within the tank is below a predetermined maximum level and an upwardly buoyed position covering said discharge hole when liquid reaches said predetermined maximum level,

said float being adapted when in said upwardly buoyed position for causing piloting liquid pressure to increase in the chamber and shift the piston from the open position to the closed position,

said piston having a hollow interior and an open lower end,

said opposite end of the body including a riser projecting upwardly into the interior of the piston through said open lower end thereof.

5. An overfill prevention valve as claimed in claim 4, said pilot port being located in said riser.

6. An overfill prevention valve as claimed in claim 5,

said piston having a conical nose facing in the upstream direction and an annular, integral skirt projecting downwardly from the lower extremity of said nose,

said skirt surrounding said riser in radially spaced relation thereto.

8. A liquid storage tank comprising:

a top wall having a hole;

an overfill prevention valve; and

mounting structure mounting said valve on the tank in such a manner that the valve projects downwardly through said hole and into the tank,

said valve comprising

an elongated hollow valve body having an inlet at one end adapted for connection to a source of supply of liquid under pressure for filling the tank, at least one laterally disposed outlet downstream from said inlet for delivering liquid into the tank from the body, a valve seat between the inlet and the outlet, and a pilot port at an opposite end of the body;

a piston axially movable within said body between an open position wherein the piston is spaced away from said seat to permit incoming liquid to flow through the outlet and into the tank and a closed position wherein the piston is sealingly engaged with said seat to prevent liquid flow through the outlet and into the tank,

said piston cooperating with said opposite end of the body to define an expandable actuating chamber that communicates with said pilot port,

said piston having an orifice disposed for communicating the chamber with the inlet so that the chamber receives piloting liquid from the flow entering the body;

a guide tube fixed to and projecting downwardly from said opposite end of the body and communicating with said pilot port,

said guide tube having a discharge hole at a location spaced below said body for permitting piloting liquid to escape from the chamber to the tank via the pilot port, the guide tube, and the discharge hole; and

a float buoyantly shiftable along and relative to said tube between a lower position uncovering said discharge hole when liquid within the tank is below a predetermined maximum level and an upwardly buoyed position covering said discharge hole when liquid reaches said predetermined maximum level,

said float being adapted when in said upwardly buoyed position for causing piloting liquid pressure to increase in the chamber and shift the piston from the open position to the closed position.

9. A liquid storage tank as claimed in claim 8,

said piston having a generally tapered nose facing in the upstream direction,

said nose being disposed to engage said seat when the piston is in the closed position and to direct liquid toward said outlet when the piston is in the open position.

10. A liquid storage tank as claimed in claim 9,

said nose having an uppermost, central tip,

said orifice being disposed at said tip.

14. A liquid storage tank as claimed in claim 8,

said mounting structure including an annular flange on said top wall overlying and in axial alignment with said hole,

said flange being internally threaded,

said one end of the body being externally threaded and threadably engaged with said flange,

said outlet being disposed below said flange.

15. A liquid storage tank as claimed in claim 14,

said externally threaded one end of the body including a portion projecting upwardly through and beyond said flange,

further comprising an internally threaded coupling neck threadably secured to said portion of the externally threaded one end of the body.

16. A liquid storage tank as claimed in claim 8,

said mounting structure including a tubular fitting on said top wall projecting upwardly therefrom in axial alignment with said hole,

said fitting having an externally threaded upper end,

said mounting structure further including a coupling neck having an enlarged, internally threaded annular skirt threadably attaching the neck to the threaded upper end of the fitting,

said coupling neck having an internally threaded bore spaced radially inwardly from said skirt,

said one end of the valve body being externally threaded and threadably received by said bore to secure the body to the coupling neck,

said outlet being disposed above said hole within said fitting.

11. A liquid storage tank comprising:

a top wall having a hole;

an overfill prevention valve; and

mounting structure mounting said valve on the tank in such a manner that the valve projects downwardly through said hole and into the tank,

said valve comprising

an elongated hollow valve body having an inlet at one end adapted for connection to a source of supply of liquid under pressure for filling the tank, at least one laterally disposed outlet downstream from said inlet for delivering liquid into the tank from the body, a valve seat between the inlet and the outlet, and a pilot port at an opposite end of the body;

a piston axially movable within said body between an open position wherein the piston is spaced away from said seat to permit incoming liquid to flow through the outlet and into the tank and a closed position wherein the piston is sealingly engaged with said seat to prevent liquid flow through the outlet and into the tank,

said piston cooperating with said opposite end of the body to define an expandable actuating chamber that communicates with said pilot port,

said piston having an orifice disposed for communicating the chamber with the inlet so that the chamber receives piloting liquid from the flow entering the body;

a guide tube fixed to and projecting downwardly from said opposite end of the body and communicating with said pilot port,

said guide tube having a discharge hole at a location spaced below said body for permitting piloting liquid to escape from the chamber to the tank via the pilot port, the guide tube, and the discharge hole; and

a float buoyantly shiftable along and relative to said tube between a lower position uncovering said discharge hole when liquid within the tank is below a predetermined maximum level and an upwardly buoyed position covering said discharge hole when liquid reaches said predetermined maximum level,

said float being adapted when in said upwardly buoyed position for causing piloting liquid pressure to increase in the chamber and shift the piston from the open position to the closed position,

said piston having a hollow interior and an open lower end,

said opposite end of the body including a riser projecting upwardly into the interior of the piston through said open lower end thereof.

12. A liquid storage tank as claimed in claim 11,

said pilot port being located in said riser.

13. A liquid storage tank as claimed in claim 12,

said piston having a conical nose facing in the upstream direction and an annular, integral skirt projecting downwardly from the lower extremity of said nose,

said skirt surrounding said riser in radially spaced relation thereto.