Fuel Pressure Regulator Vacuum

I have a '98 4.3L and removed the intake manifold to get at the fuel body to replace the pressure regulator. I was surprised to find no vacuum hose attached to the regulator and could find none that may have come loose. Is this correct? If there should be one, where does it come from?

There is no vac hose to the fuel pressure regulator.. Strictly fluidic pressure.

not that type of presure....reason theres no line on there is because a fuel pressure regulator adjusts the fuel pressure according to manifold vacumm , all vacumm controled pressure reg.'s go to the manifold past the TB , hence the reason there was no line on the reg. , its already in the manifold and at full vacumm