Particular attention shall be paid to inner cleanliness of piping. Prefabricated piping transported to the construction site shall be laid down on supports. Adequate measures (such as capping) shall be taken to ensure that piping is protected from the ingress of sand and foreign material. Protective coatings shall be inspected periodically. All machined parts to be coated with Shell Ensis fluid.
Stainless steel (alloys containing more than 10% chromium) equipment, components and materials shall be protected as follows:
Under cover.
Not in contact with the soil or with porous supports such as raw wood. Protective coatings are acceptable alternatives to covered storage.
In addition, austenitic stainless steel shall not be exposed to salt water or salt spray.
Consideration shall be given to pipelines integrated in a "SYSTEM" with a main piece of equipment (exchanger, pump etc.) If this is the case they come under the responsibility of the "SYSTEM" engineer when ready. The "SYSTEM" is drained, dried and a nitrogen blanket of O.5 bar(g) applied. Nitrogen pressure is checked periodically.
Inspect painting and insulation periodically and take remedial action where required
Bolts shall be coated with heavy grease, such as Shell Rhodina. When the "SYSTEM" is being prepared for precommissioning, after a prolonged shutdown, selective service testing shall be considered and only those gaskets that fail shall be renewed.
Machined parts shall be coated with Shell Ensis fluid during storage. After erection moisture proof tape shall be wrapped around aperture of adjacent faces of flange joints. Shell Ensis fluid SDC shall be applied to nuts and exposed threading of studs.
Stuffing box packings are left intact during idle periods. If repacking after start-up would be very cumbersome, packings can be replaced before precommissioning.
All piping shall be properly drained and dried after testing. Open flanges if required. For all lines filling with nitrogen is recommended if prolonged standstill is forecasted, (especially for gas, oxygen and chlorine lines). Alternatively dry air can be considered if nitrogen is impractical.
The dry air or inert gas system shall not contain oily matter or solid particles. After the preservation treatment is finished the system shall be blanked off and the gas pressure of the system checked periodically
Valves and appendages, except instruments, are treated together with the "SYSTEM" they are incorporated in and inspected valves shall be opened fully. Motor operated valves and hydraulic valves are operated periodically.
Exterior parts shall be coated, especially the threaded stem. During idle periods no special care is given to valve packings.
For large piping systems installation of thermal relief valves can be considered when filled with liquid.
Special attention shall be paid instrument connections to be capped or plugged and spools to be installed where required.
Special attention shall be paid at an early stage to lightning protection of elevated lines. Verify the earthing connection.
