A fluid system comprising: - a fluid tank; - a pump connected to the fluid tank; - a fluid circuit comprising: - a supply line for carrying a fluid from the pump to at least one equipment, the supply line having an inlet and an outlet and further having a portion which is divided into a main line including a heat exchanger, and a by-pass line for by-passing said heat exchanger, the main line and the by-pass line being arranged in parallel and both having an inlet (11, 16) and an outlet (12, 17); wherein the pump is arranged between the fluid tank and the supply line inlet, and wherein said portion of the supply line is located between the pump and the equipment; - a first valve for controlling the respective fluid flows in the main line and in the by-pass line, and a first control device for controlling the first valve depending on a first parameter of the fluid; - a pressure regulation circuit for carrying fluid from the supply line towards the fluid tank, said pressure regulation circuit comprising a pressure regulation valve for controlling the flow of fluid directed back to the fluid tank; wherein the pressure regulation circuit comprises: - a first recirculation line branching from the supply line downstream from the by-pass line outlet, for carrying fluid from the supply line towards the fluid tank; - a second recirculation line branching from the supply line upstream from the by-pass line inlet, for carrying fluid from the supply line towards the fluid tank; both recirculation lines (21, 22) allowing directing part of the fluid from the supply line back to the fluid tank before it enters the equipment(s); - a second valve for controlling the respective fluid flows in the first recirculation line and in the second recirculation line, and a second control device for controlling the second valve depending on a second parameter of the fluid. - a fluid tank; - a pump connected to the fluid tank; - a fluid circuit comprising: - a supply line for carrying a fluid from the pump to at least one equipment, the supply line having an inlet and an outlet and further having a portion which is divided into a main line including a heat exchanger, and a by-pass line for by-passing said heat exchanger, the main line and the by-pass line being arranged in parallel and both having an inlet (11, 16) and an outlet (12, 17); wherein the pump is arranged between the fluid tank and the supply line inlet, and wherein said portion of the supply line is located between the pump and the equipment; - a first valve for controlling the respective fluid flows in the main line and in the by-pass line, and a first control device for controlling the first valve depending on a first parameter of the fluid; - a pressure regulation circuit for carrying fluid from the supply line towards the fluid tank, said pressure regulation circuit comprising a pressure regulation valve for controlling the flow of fluid directed back to the fluid tank; wherein the pressure regulation circuit comprises: - a first recirculation line branching from the supply line downstream from the by-pass line outlet, for carrying fluid from the supply line towards the fluid tank; - a second recirculation line branching from the supply line upstream from the by-pass line inlet, for carrying fluid from the supply line towards the fluid tank; both recirculation lines (21, 22) allowing directing part of the fluid from the supply line back to the fluid tank before it enters the equipment(s); - a second valve for controlling the respective fluid flows in the first recirculation line and in the second recirculation line, and a second control device for controlling the second valve depending on a second parameter of the fluid. - a supply line for carrying a fluid from the pump to at least one equipment, the supply line having an inlet and an outlet and further having a portion which is divided into a main line including a heat exchanger, and a by-pass line for by-passing said heat exchanger, the main line and the by-pass line being arranged in parallel and both having an inlet (11, 16) and an outlet (12, 17); wherein the pump is arranged between the fluid tank and the supply line inlet, and wherein said portion of the supply line is located between the pump and the equipment; - a first valve for controlling the respective fluid flows in the main line and in the by-pass line, and a first control device for controlling the first valve depending on a first parameter of the fluid; - a pressure regulation circuit for carrying fluid from the supply line towards the fluid tank, said pressure regulation circuit comprising a pressure regulation valve for controlling the flow of fluid directed back to the fluid tank; - a first recirculation line branching from the supply line downstream from the by-pass line outlet, for carrying fluid from the supply line towards the fluid tank; - a second recirculation line branching from the supply line upstream from the by-pass line inlet, for carrying fluid from the supply line towards the fluid tank; both recirculation lines (21, 22) allowing directing part of the fluid from the supply line back to the fluid tank before it enters the equipment(s); - a second valve for controlling the respective fluid flows in the first recirculation line and in the second recirculation line, and a second control device for controlling the second valve depending on a second parameter of the fluid.