High-purity regulators use stainless diaphragms and metal-to-metal seals to avoid contamination and outgassing. They are specified by delivery pressure range and by the purity level they can maintain. A general-purpose brass regulator will introduce contamination that matters at 99.999% purity levels.
Manifolds let several cylinders feed one outlet with automatic changeover, which keeps supply continuous without stopping to swap cylinders. They require a specific inlet configuration and are usually assembled to order for the gas and pressure range.
Purge equipment — flowmeters, purge dams, soluble purge film and oxygen monitors — is used when welding stainless and duplex pipe, where oxygen in the purge gas causes discolouration and loss of corrosion resistance. The oxygen content of the purge must be measured, not assumed.
