Suggestion on adding valve positioner to pressure relief valve of purification system

The pressure relief of molecular sieve in the purification system is generally rapid in the early stage, not complete and running overtime in the later stage. The pressure relief degree is adjusted by the manual stop valve in front of the pressure relief valve. Through practical adjustment, no matter how it is adjusted, the pressure relief in front is fast, or the pressure can not be exhausted. It is suggested that the valve positioner should be added to the automatic pressure relief valve, and the pressure linear adjustment should be programmed, so that the impact on molecular sieve will be much smaller.