There are some products out there that you can use to stop "water hammer". One of these is called "Water Hammer Arrestors". This would just be installed in the line, but depending on the severity of the water hammer, you might have to have multiples or a very large one. Another avenue would be to switch to a higher quality valve and one that may offer pressure regulation. Sometimes this can eliminate water hammer. One of the tricks that golf courses used war a series of fluid resisters in the solenoid chamber. This would slow the "on" and "off" speed of the valve and usually eliminating the water hammer. Most of this will not be compatible with your brand of valves, but it is a start to get you in the right direction. Best of luck!
Josh
Irrigation /Landscape Lighting / Pump and Well Specialist