A pressure compensating system (1) for a dual fluid flow system, wherein the pressure compensating system (1) comprises: a fluid pipe (3) having a first fluid pipe portion (3a) and a second fluid pipe portion (3b), wherein the first fluid pipe portion (3a) has a first fluid inlet (5a) and a first fluid outlet (7a) for a first fluid flow (O.sub.2), wherein the second fluid pipe portion (3b) has a second fluid inlet (5b) and a second fluid outlet (7b) for a second fluid flow (H.sub.2) separate from the first fluid flow (O.sub.2), and a pressure compensator (11) arranged in the fluid pipe (3), separating the first fluid pipe portion (3a) and the second fluid pipe portion (3b), wherein the pressure compensator (11) is configured to move in the fluid pipe (3) between the first fluid outlet (7a) and the second fluid outlet (7b) to thereby at least partially obstruct one of the first fluid outlet (7a) and the second fluid outlet (7b) in response to a pressure differences between the first fluid pipe portion (3a) and the second fluid pipe portion (3b) to provide pressure compensation between the first fluid pipe portion (3a) and the second fluid pipe portion (3b).

A pressure compensating system (1) for a dual fluid flow system, wherein the pressure compensating system (1) comprises: a fluid pipe (3) having a first fluid pipe portion (3a) and a second fluid pipe portion (3b), wherein the first fluid pipe portion (3a) has a first fluid inlet (5a) and a first fluid outlet (7a) for a first fluid flow (O.sub.2), wherein the second fluid pipe portion (3b) has a second fluid inlet (5b) and a second fluid outlet (7b) for a second fluid flow (H.sub.2) separate from the first fluid flow (O.sub.2), and a pressure compensator (11) arranged in the fluid pipe (3), separating the first fluid pipe portion (3a) and the second fluid pipe portion (3b), wherein the pressure compensator (11) is configured to move in the fluid pipe (3) between the first fluid outlet (7a) and the second fluid outlet (7b) to thereby at least partially obstruct one of the first fluid outlet (7a) and the second fluid outlet (7b) in response to a pressure differences between the first fluid pipe portion (3a) and the second fluid pipe portion (3b) to provide pressure compensation between the first fluid pipe portion (3a) and the second fluid pipe portion (3b).

A cap assembly for a container comprises a cap and a body coupled to the cap. The body includes a peripheral wall and a valve seat. The valve seat includes a first side facing the cap and a second side facing away from the cap. A first check valve having an elastic valve body is positioned at the second side of the seat. A second check valve having an elastic valve body is positioned at the first side of the valve seat. When a pressure at the first side of the valve seat exceeds a pressure at the second side of the valve seat by a first predetermined value, the first check valve opens; and when the pressure at the second side exceeds the pressure at the first side by a second predetermined value, the second check valve opens.

A cap assembly for a container comprises a cap and a body coupled to the cap. The body includes a peripheral wall and a valve seat. The valve seat includes a first side facing the cap and a second side facing away from the cap. A first check valve having an elastic valve body is positioned at the second side of the seat. A second check valve having an elastic valve body is positioned at the first side of the valve seat. When a pressure at the first side of the valve seat exceeds a pressure at the second side of the valve seat by a first predetermined value, the first check valve opens; and when the pressure at the second side exceeds the pressure at the first side by a second predetermined value, the second check valve opens.

The invention relates to bung plug (10) having an integrated pressure compensation means for arrangement in a container lid of a liquid container, the bung plug (10) having a valve housing (15) below a plug depression (12), the valve housing (15) being provided with air passage openings (39, 40) and having a receiving pin (16) arranged centrically in the valve housing (15) for arranging a valve diaphragm (17) whose diaphragm hub (18) is arranged on the receiving pin (16), a radially outward ring edge (19) of the valve diaphragm (17) being in contact with a ring shoulder (20) of the valve housing (15), the diaphragm hub (18) being arranged between a depression bottom (14) of the plug depression (12) and a lid hub (22) of a surge lid (21) arranged on the receiving pin (16) and provided with air passage openings (39, 40), a surge disk (32) being provided between the surge lid (21) and the valve diaphragm (17), wherein the surge disk (32) and the surge lid (21) are realized as a unit and the surge lid (21) has a mounting disk (26) arranged at an axial distance from the surge disk (32) for mounting in the valve housing (15), said mounting disk (26) having an outer mounting edge for forming an engagement connection with a mounting seat arranged at an inner side (29) of a housing wall (30) of the valve housing (15).

The invention relates to bung plug (10) having an integrated pressure compensation means for arrangement in a container lid of a liquid container, the bung plug (10) having a valve housing (15) below a plug depression (12), the valve housing (15) being provided with air passage openings (39, 40) and having a receiving pin (16) arranged centrically in the valve housing (15) for arranging a valve diaphragm (17) whose diaphragm hub (18) is arranged on the receiving pin (16), a radially outward ring edge (19) of the valve diaphragm (17) being in contact with a ring shoulder (20) of the valve housing (15), the diaphragm hub (18) being arranged between a depression bottom (14) of the plug depression (12) and a lid hub (22) of a surge lid (21) arranged on the receiving pin (16) and provided with air passage openings (39, 40), a surge disk (32) being provided between the surge lid (21) and the valve diaphragm (17), wherein the surge disk (32) and the surge lid (21) are realized as a unit and the surge lid (21) has a mounting disk (26) arranged at an axial distance from the surge disk (32) for mounting in the valve housing (15), said mounting disk (26) having an outer mounting edge for forming an engagement connection with a mounting seat arranged at an inner side (29) of a housing wall (30) of the valve housing (15).

A valve apparatus [11] for connection to a tank or pipe, the valve apparatus [11] comprises a housing [12], a first opening [176a] and a second opening [177a] communicating with respective first conduit [16] and second conduit [17] each for providing ingress and egress of fluid into and out of the housing [11] through the first opening [176a] and the second opening [177a], and discrete first and second valve means or valves [14; 15] which are spaced apart from one another, the first and second valve means or valves [14; 15] selectively controlling fluid flow between the first and second conduits [16; 17], wherein, in use, the principal flow axes along the first conduit [16] and second conduit [17] are parallel and opposed, the first valve means or valve [14]is configured to open when the pressure in the first conduit [16] is greater than a first pressure and the second valve means or valve [17] is configured to open when the pressure in the first conduit [16] is less than the first pressure.

Apparatus to protect sealing surfaces of thief hatches are disclosed. An example apparatus includes a first portion that is attachable to a tank, wherein the first portion includes a first opening, and a second portion that is pivotably coupled to the first portion. The example apparatus is structured to provide access to an aperture in the tank via the first opening when the second portion is in an open state and maintain a pressure of the tank within a specified range by selectively separating one or more seals from one or more corresponding sealing surfaces when the second portion is in a closed state, wherein the second portion includes the one or more seals and the one or more corresponding sealing surfaces.

Apparatus to protect sealing surfaces of thief hatches are disclosed. An example apparatus includes a first portion that is attachable to a tank, wherein the first portion includes a first opening, and a second portion that is pivotably coupled to the first portion. The example apparatus is structured to provide access to an aperture in the tank via the first opening when the second portion is in an open state and maintain a pressure of the tank within a specified range by selectively separating one or more seals from one or more corresponding sealing surfaces when the second portion is in a closed state, wherein the second portion includes the one or more seals and the one or more corresponding sealing surfaces.

An expansion tank includes a tank body mounted inside a housing forming a sump, where the tank body defines an internal expansion volume. A fluid inlet tube on the tank body has an upper end open to the sump and a lower end open to the internal expansion volume. A single 2-way check valve is located at the lower end of the tube, and fluid enters the expansion volume when the pressure in the sump exceeds the pressure in the expansion volume by a first predetermined amount, and fluid exits the expansion volume to the sump when the pressure in the expansion volume exceeds the pressure in the sump by a second predetermined amount. The check valve may be a combination duckbill valve and umbrella valve. The tank body may include a cover on which the inlet tube is formed.