This standard is applicable to flared pressure gauge pipe joints used in pipeline systems with oil and gas as medium.
GB/T 5645.1-1985 history
2008GB/T 5645-2008 Flared couplings.Connector for pressure gauge
1985GB/T 5645.1-1985 Flared type tube fittings--Connector for pressure gauge--Assembly
GB/T 5645.1-1985 Flared type tube fittings--Connector for pressure gauge--Assembly was changed to GB/T 5645-2008 Flared couplings.Connector for pressure gauge.