Enables external transmitter zeroing via single handle.Lockable handle may be screw locked in any position or padlocked in OFF position, for personnel safety.AG Mount direct pipe stand mounting enables early installation without transmitter and easy instrument removal for maintenance.Correct fixed valve sequence ensures accurate transmitter pressurization and zeroing. Port sequencing always admits high side pressure to transmitter first, preventing possible zero shift from reverse over-ranging.Safe venting of manifold and instrument cavities protects personnel during maintenance.Seal fluids cannot be lost when manipulating to ZERO, RUN or OFF, providing major savings in down time and seal fluids.Foolproof manual configuration prevents incorrect transmitter over-ranging and transmitter burn-out due to equalizer valve being left open for flow.