There are two so-called balance methods, one is one-way sequence valve, and the other is pressure maintaining balance valve represented by Rexroth. The first type is the most common. It is a combination of one-way valve and sequential valve. It is generally installed on the rod cavity of the oil cylinder to adjust the back pressure and stabilize the load.
As for the difference between relief valve and sequential valve, it is actually the same thing, but the combination of oil control and oil discharge is different. Generally, the overflow valve controls leakage, and the sequence valve must leak. The balance valve is a combination of sequence valve and one-way valve, remember?