IEC TR 60877:1999 pdf download.Procedures for ensuring the cleanliness of industrial-process measurement and control equipment in oxygen service
1 Scope
This report outlines the procedures for cleaning industrial-process measurement and control equipment to be used for oxygen service, verifying this cleanliness and ensuring that the cleanliness of the equipment will be maintained up to the stage where the equipment is installed. This report does not apply to measurement and control equipment for welding, which is covered by ISO 51 71 . Oxygen service is defined as equipment or part thereof being in contact with oxygen-rich gas mixtures and other oxydizing gases (e.g. laughing gas). Greases, oils, thread lubricants, dirt, water, filings, paints, varnishes, scales, powder, etc., shall be removed because many of these materials, in particular oils and hydrocarbon greases, can react violently in the presence of oxygen and initiate fires or explosions. This report consequently covers the cleanliness procedures for the preparation, assembling, inspection, protection during transportation, storage and handling and installation of equipment, accessories or replacement parts intended for oxygen service.
NOTE – Many factors can influence the reaction in the presence of oxygen. Those may be:
– a higher oxygen pressure;
– a higher temperature;
– the fact that oxygen flows, or is only present as a static pressure within equipment or part thereof.
2 Reference document
ISO 51 71 :1 995, Pressure gauges used in welding, cutting and allied processes
3 Procedures
In preparing, cleaning and assembling any equipment, accessory or part for oxygen service,
the following procedures shall be explicitly observed.
3.1 Orders for equipment for oxygen service
Each order shall specify that the equipment and/or accessories are to be cleaned, prepared,
marked and packed for use in oxygen service. Any order for replacement parts issued
separately from the orders for equipment and/or accessories shall also state clearly that the
parts so ordered are to be cleaned, prepared, marked, and packed for use in oxygen service.
3.2 Cleaning
Prior to cleaning, the materials used in the equipment, accessory or part, and their surface
finish shall be checked in order to determine the appropriate manner of cleaning and the
suitable cleaning agent. All foreign material such as mill scale, dirt, grit, solid objects and
hydrocarbons shall be removed. Removal may be accomplished by grinding, wire brushing,
blast cleaning, sweeping, vacuuming, swabbing, etc. All particles resulting from the grinding
and wire brushing operations shall be thoroughly removed.
3.2.1 Mechanical cleaning
This type of cleaning may be accomplished by blast cleaning, wire brushing or grinding.
3.2.1.1 Blast cleaning
Blast cleaning may be described as the use of abrasives propelled through nozzles against the
surface of pipe, fittings or cavities to remove mill scale, rust, varnish, paint or other foreign
matter; when resorted to, blast cleaning forms part of the manufacturing process. The medium
propelling the abrasive shall be oil-free unless the oil is to be removed by subsequent cleaning.
Specific abrasive materials shall be suitable for performing the cleaning without depositing
contaminants that cannot be removed by subsequent cleaning. Care shall be taken when blast
cleaning so as to not remove an excessive amount of parent metal. The blasting medium and
residue shall be removed to meet the cleanliness levels suggested herein for oxygen service
equipment, accessory or part.
3.2.1.2 Wire brushing or grinding
Accessible surfaces may be wire brushed. Welds may be ground and wire brushed to remove slag, grit or excess weld material. Carbon steel wire brushes shall not be used on aluminium or stainless steel surfaces. Any wire brushes previously used on carbon steel shall not be used on aluminium or stainless steel surfaces.
IEC TR 60877:1999 pdf download
