HYDAX introduces for the first time anywhere, single block 2, 3 or 4 stations gauge isolator valves. The valves are designed to prevent surge damage to a gauge in all types of hydraulic circuits. The spring returned facility is the same as in a single station valve. The high performance, low drain leakage characteristic is maintained in the multi-station valves. Only one gauge and one drain line for all the ports reduces plumbing and additional instrumentation cost.