The datasheet says that the input is a differential amplifier. Therefore, one way of controlling the valve is to use two PWM pins, generate a 0 -> 10V signal from each one, and feed them to the inputs. Set one of the outputs to zero (depending on which way you want to move the valve) and the other to 0 to 10V. This requires 2 PWM pins to control the valve, but does not need a negative supply. The attached schematic is one way of generating one 0-10V signal.
Alternatively, only use a PWM pin to generate one of the inputs, and switch the other to 0V or +10V from a digital output pin.
