A high pressure tool assembly includes a hand control valve mechanically connectable to a tool. An intensifier is fluidly connected to the hand control valve and to the tool. The intensifier increases pressure of an operating fluid to be supplied to the tool. A first fluid circuit conveying the first operating fluid is formed between the intensifier and the tool. A second fluid circuit conveying a second operating fluid is formed between the hand control valve and the intensifier. The first fluid circuit operates at a first pressure. The second fluid circuit operates at a second pressure. The first pressure is higher than the second pressure. The first fluid circuit is isolated from the second fluid circuit.