This part of EN ISO 10438 in conjunction with of EN ISO 10438-1 specifies requirements for support systems for selfacting gas seals (dry gas seals), for example as described in ISO 10439 and ISO 10440-1. ISO 10438 in its entirety specifies requirements for lubrication systems, oil-type shaft-sealing systems, dry-gas face-type shaftsealing systems and control-oil systems for general- or special-purpose applications. These systems may serve equipment such as compressors, gears, pumps and drivers. This part of ISO EN 10438 is intended to be used for services in the petroleum, petrochemical and natural gas industries as well as other industries by agreement. This part of EN ISO 10438 does not apply to internal combustion engines.