Machine provided with a machine element (2) and an oil pump (4) and a motor (3) to drive the machine element (2) and the oil pump (4), whereby the oil pump (4) is provided with a shaft (13) with a rotor (12), whereby the oil pump (4) is provided to pump oil from an oil reservoir (5) via an inlet channel (8) to nozzles that lead into the motor (3) and/or machine element (2) to lubricate and/or cool one or more bearings or other machine components, characterized in that in the inlet channel (8), near the oil pump (4) a dam (16) is provided that is higher than the height (A) of the central axis (18) of the shaft (13) of the oil pump (4) minus the smallest diameter (B) of the rotor (12) of the oil pump (4) divided by two.

An oil scavenge system for a gas turbine engine comprising an oil tank and at least one bearing chamber. The oil scavenge system comprises at least one primary scavenge pump, a manifold, a secondary scavenge pump, a deaerator and a filter unit. The at least one primary scavenge pump is configured to pump oil from the at least one bearing chamber to the manifold whilst raising the pressure of the oil from a starting pressure to a first pressure elevated with respect to the starting pressure. The manifold is pressurised to substantially maintain the oil at said first pressure. The secondary scavenge pump is configured to pump oil from the manifold at the first pressure and to raise the pressure of the oil to a second pressure elevated with respect to the first pressure before pumping the oil to the deaerator and through the filter unit to the oil tank.

An oil scavenge system for a gas turbine engine comprising an oil tank and at least one bearing chamber. The oil scavenge system comprises at least one primary scavenge pump, a manifold, a secondary scavenge pump, a deaerator and a filter unit. The at least one primary scavenge pump is configured to pump oil from the at least one bearing chamber to the manifold whilst raising the pressure of the oil from a starting pressure to a first pressure elevated with respect to the starting pressure. The manifold is pressurised to substantially maintain the oil at said first pressure. The secondary scavenge pump is configured to pump oil from the manifold at the first pressure and to raise the pressure of the oil to a second pressure elevated with respect to the first pressure before pumping the oil to the deaerator and through the filter unit to the oil tank.

A system and methods according to which a controller communicates control signals to a first frac leg, which includes a wellhead operably associated with a first wellbore, a valve operably coupled to the wellhead, opposite the first wellbore, a frac line operably coupled to the wellhead, and a zipper module operably coupled to the frac line, opposite the wellhead. The first frac leg includes a first sub-controller that receives control signals from the controller. A grease system lubricates the first frac leg and the zipper module. The grease system includes a second sub-controller that receives control signals from the controller. A second frac leg is operably associated with a second wellbore. The second frac leg includes a third sub-controller that receives control signals from the controller. The first, second, and/or third sub-controllers may receive control signals from the controller via a communication bus.

An arrangement and a method for sealing a propeller shaft of a marine vessel. The arrangement including a shaft seal arrangement and a lubrication arrangement including a lubricant circulation line for conducting lubricant to and from the shaft seal arrangement and a lubricant circulator. The lubricant circulation line includes a connection line that is connected in fluid connection with the lubricant circulation line downstream of the lubricant circulator and upstream of the shaft seal arrangement, and that is connected in fluid connection with a second part of the lubricant circulation line so as to selectively conduct a part of the flow of lubricant past the shaft seal arrangement. At least one hydraulically operated pressure relief means is configured to control the flow of lubricant in the connection line.

An arrangement and a method for sealing a propeller shaft of a marine vessel. The arrangement including a shaft seal arrangement and a lubrication arrangement including a lubricant circulation line for conducting lubricant to and from the shaft seal arrangement and a lubricant circulator. The lubricant circulation line includes a connection line that is connected in fluid connection with the lubricant circulation line downstream of the lubricant circulator and upstream of the shaft seal arrangement, and that is connected in fluid connection with a second part of the lubricant circulation line so as to selectively conduct a part of the flow of lubricant past the shaft seal arrangement. At least one hydraulically operated pressure relief means is configured to control the flow of lubricant in the connection line.

A hydraulic fracturing plan executable by a hydraulic fracturing system to hydraulically fracture a plurality of oil and gas wells.

A bypass apparatus for lubricant in an unregulated pressurized gearbox including: a block including a lubricant inlet in fluid communication with a pressure relief valve, wherein the pressure relief valve diverts lubricant into the gearbox or into an oil filter, wherein lubricant is returned to the gearbox when the lubricant is cold and/or pressure at the pressure relief valve is high to reduce damage to the gearbox caused by high pressure during a cold start, and when the lubricant temperature increases and the pressure is reduced the pressure relief valve closes and lubricant enters the oil filter.

A transmission device includes a casing accommodating a transmission gear and having an oil sump for retaining oil. The oil in the oil sump flows from a lubrication pump through a lubrication passage and is injected to the transmission gear. A connection portion is provided in a part of the lubrication passage, which part is disposed outside the casing. A direction control valve is provided downstream of the lubrication pump and upstream of the connection portion in the lubrication passage with respect to a flow direction of the oil. The direction control valve is configured to open the lubrication passage when a hydraulic pressure in the lubrication passage exceeds a predetermined value and to close the lubrication passage when the hydraulic pressure is equal to or lower than the predetermined value.

A transmission device includes a casing accommodating a transmission gear and having an oil sump for retaining oil. The oil in the oil sump flows from a lubrication pump through a lubrication passage and is injected to the transmission gear. A connection portion is provided in a part of the lubrication passage, which part is disposed outside the casing. A direction control valve is provided downstream of the lubrication pump and upstream of the connection portion in the lubrication passage with respect to a flow direction of the oil. The direction control valve is configured to open the lubrication passage when a hydraulic pressure in the lubrication passage exceeds a predetermined value and to close the lubrication passage when the hydraulic pressure is equal to or lower than the predetermined value.