One could argue "no" I think there is enough evidence around from people putting pressure gauges on the system & finding that there is barely enough pressure to operate the gauge, to indicate that the relief valve is of questionable value. However, when they were first built & used in their native country with cold winters & heavy weight single viscosity oils the valve may have got a little exercise at start up.That will work but you have to ask if it takes all that effort does the damm thing do any good in operation at all?