THERMODYNAMIC VALVE FOR RETAINING VAPOURS AND GASES AND RELIEVING PRESSURE AND VACUUM

Abstract

A thermodynamic valve for retaining vapours and gases and relieving pressure and vacuum for use in the venting of tanks or reservoirs of combustible liquids (fluids), said valve comprising: upper diaphragm ring (3a) and lower diaphragm ring (3b) that act through the thermodynamic action of the positive and negative pressures inside positive pressure (4) and negative pressure (5) chambers fixed to one another, a cap (2) screwed on the body of positive pressure chamber (4) and having upwardly directed lateral openings and a rupture seal (1) fitted in the upper section of cap (2). A base (5.1) with an inner fire-break fabric (6) is positioned on the inner lower section of negative pressure chamber (5) and connected to the fuel tank venting pipe.

Claims

1. A thermodynamic valve for retaining vapours and gases and relieving pressure and vacuum, characterized in that it comprises two diaphragm rings (3a,3b) that act through the thermodynamic action of the positive and negative pressures inside the positive (4) and negative (5) chambers, fixed to one another by a screw thread, comprising a cap (2) provided with upward lateral openings screwed on the body of chamber (4), extra safety being imparted to the valve by a non-metallic rupture seal (1) fitted on the upper part of cap (2), further containing, positioned on the inner lower portion of valve chamber (5) a screw-threaded base (5.1) to be fixed to the fuel tank venting pipe (breathing) and provided with a stainless steel fire-break fabric (6) fixed by an O-ring (7) and further, a double safety fire-break fabric (4.1) positioned between the positive chamber (4) and the negative chamber (5).

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0014] The characterization of the present invention is obtained by exemplary Figures of the thermodynamic valve for retaining vapours and gases and pressure and vacuum relief to enable the product to be fully reproduced by the most suitable technique, allowing the full functionality of the claimed object.

[0015] These Figures are merely illustrative, and variations are admitted provided they do not deviate from the initially claimed. In this case,

[0016] FIG. 1 is a perspective view of the proposed valve;

[0017] FIG. 2 is a cross-section cut of the valve; and

[0018] FIG. 3 is an exploded view of the valve.

DETAILED DESCRIPTION OF THE INVENTION

[0019] On the basis of the illustrated Figures which express the best form or preferred mode of performing the designed product the description of the specification follows a detailed and consecutive numbering, where the aspects which would be implied by the adopted representation are exposed to clearly determine the intended protection.

[0020] The present valve is compact, its working principle makes use of the automatic modulation of two diaphragm rings (3a,3b) by the thermodynamic action of the positive and negative pressures in the interior of chambers (4), of positive pressure, and (5), of negative pressure, fixed together by threads.

[0021] A cap (2) with upward lateral openings (not represented) is threaded to the chamber (4) body.

[0022] The valve is provided with extra safety by means of a non-metallic rupture seal (1) fitted to the upper section of cap (2) and designed to prevent excessive pressure.

[0023] The modulated sealing provided by the valve favours the condensation of vapours and gases on the inner fuel tank (not represented) walls, the coalescing of formed droplets resulting in the return to the mass of fluid stored in the tank.

[0024] Positive pressure occurs when fuel enters the fuel tank by loading, that is, when the tank receives fuel.

[0025] Relief in positive pressure occurs by the effect of generating increase in air and/or gases within the fuel tank, leading to the upward movement of upper diaphragm ring (3a) inside positive pressure chamber (4) to alleviate the positive pressure generated within the fuel tank. Consequently, lower diaphragm ring (3b) within negative pressure chamber (5) will prevent air or gases at positive pressure from exiting the lower apertures (not represented) of negative pressure chamber (5).

[0026] Negative pressure (vacuum) occurs when fuel exits the fuel tank by drainage, that is, when the fuel is being moved from the fuel tank to the supply at the service station.

[0027] Relief in negative pressure occurs by generating vacuum inside the fuel tank, lower diaphragm ring (3b) being moved upwards within negative pressure chamber (5) aiming at enabling air to enter the fuel tank and preventing collapse. Consequently, upper diaphragm ring (3a) positioned at the positive pressure chamber (4) will be kept shut, allowing equalization of pressures within the fuel tank.

[0028] A base (5.1) positioned on the inner lower section of negative pressure chamber (5) is provided with threads for fixation to the fuel tank venting pipe (breathing), the interior of same having a stainless-steel fire-break fabric (6) attached by an O-ring (7) aiming both at preventing combustion access to the interior of the system and retain solid particles.

[0029] In order to retain solid particles, the valve of the invention is provided with a further safety element by means of a stainless-steel fire-break fabric (4.1), the same being positioned between the positive pressure chamber (4) and the negative pressure chamber (5).

[0030] Features of said thermodynamic valve of pressure and vacuum relief: [0031] extreme sealing, securing minimum product losses and reduced environmental impact; and [0032] Adjustment pressure very close to opening pressure, enabling optimum system pressure maintenance.