A hot dry spell will definitely hurt yield if you have not been monitoring soil moisture levels and maintaining adequate moisture. You have too much invested in equipment to do a poor job of managing the water. NDSU Extension Service personnel are available to assist you in setting up a water management program. A properly designed sprinkler package should allow no more than a 10 percent variation in water application depth over a field. A variation in applied water depth greater than 10 percent indicates some parts of the field are over irrigated and some are under irrigated.
Pressure regulators can reduce the water application variation.
This could be very important for high value crops such as potatoes and carrots. Irrigate over them and record the average depth collected at each location. Evaluate how much of the field is affected by the elevation extremes. If the affected area is small, regulators may not be of great benefit to you. Repeat this test on different parts of the field to more thoroughly evaluate the need for regulators.