Pilot-to-open check valves should not be used in paired cylinder circuits. The pilot pressure needed to open a pilot-to-open check is proportional to the load it is holding. The valve with the least load will open first, transferring the combined load to the second valve at more than double the pressure. Use counterbalance valves instead. The pilot pressure to open a counterbalance valve is inversely proportional to the load pressure. When one of the counterbalances opens first the load is transferred to the other counterbalance and lowers the pilot pressure required. The valves cooperate and lower the load with a minimum of load shift.