Spraying 28% with white streamer tips. 46 gal/ ac. Pressure while sprying at 5.5 mph is 60 lb. When I shut off at end of field pressure jumps to abput 160. This seems very high! I feel like something is going to let go. Shouldn't the spayer relieve the presure back down a lot more. Maybe I need bigger tips? What are your thoughts. Thanks.