shocks-2

[keyur trivedi]

hello,
I am writing a new topic since the page is over in the last onel My main question is that surge occurs not only during main directional valve shifts. It also occurs during shifting of valve which decides the feed control (horizontal solenoid in your circuit). Infact that is more dangerous, and that creates an accident. The whole forward stroke is devided in rapid and feed motion. Will load sensing help in that matter also? or by using a p-blocked valve will eliminate the surges. Thank you for your help and guidance!
keyur

[Doug Hanson]

Sorry, I'll try to post again tonight, got an emergency call to go to.

[Doug Hanson]

I think the difference here is your current system is meter out, which means there is back pressure through the entire system. That combined with the open transition valve cause the surging, as well as shifting of the feed control valve. You can try using counterbalance valves, but I think they will be piloted open because of the back pressure from the feed control valve. There are a few variables here, so the easiest thing to do would be to try it out.

The load sensing systems I proposed allow you to have a pressure comepnsated flow control as a meter in function, which eliminates the whole meter out back pressure issue. This will also allow you to use counterbalance valves without worying about backpressure piloting them open. It will also generate a lot less heat.

The only way to get even more precise throttle and position control would be to go with a closed loop motion control system, which is quite an expensive way to go.

If you have a system there that is ready to go, I would try out the counterbalnce valve arrangement. If that doesn't work out, you would need them for the load sensing system anyway. You could try using a 4 port, vented counterbalnce valve and plumb the vent port into the T port of your control valve so the back pressure in the meter out portion is additive to the counterbalance setting, but I don't think this is a good design idea.

[keyur trivedi]

hello,
Thanks a lot. Now I am trying to set my system with counterbalance valves first, If it doesn't work i will go for load sensing. I will tell you the result as i get. Thanks for your guidance throug this.