Page 370 - Pipelines and Risers

Pipeline Inspection, Maintenance and Repair 341

18.3.2 Pipeline Valves
Pipeline valves should be lubricated and functionally operated at least once annually and in
accordance with the valve manufacturers recommendations. Functional operation of subsea
valves should also be carried out annually. However, where valves are located in unfavorable
conditions (e.g. valve pits subject to flooding or general dampness) it may be advisable to
increase the maintenance frequencies to account for these conditions.

All valve actuators whether they be manual, pneumatic, hydraulic or electrical should be
functionally tested at least once per year and in accordance with the actuator manufacturers
recommendations.

In developing maintenance routines, account should be taken, where applicable, of the
requirement to test the equipment by remote operation or by simulating line-break conditions.
Operations involving the closure of block valves should be a co-ordinated exercise with all
the relevant parties.
18.3.3 PigTraps

Pig trap maintenance shall be camed out strictly in accordance with the manufacturers
guideline for the type of pig launcher and receiver facilities used, and these guidelines
incorporated in the maintenance routine. However, as a minimum a full inspection and survey
of the condition of the pig traps should be conducted annually, and should include:

Condition of launcher / receiver barrel;
End closure seals;
0 Bleed locks and electrical bond;
0 Locking rings;
Pig signalers;
Associated valves and pipework.
18.3.4 Pipeline Location Markers
Aerial markers and pipeline markers should be maintained on an ongoing basis with the
information contained on the marker posts verified and updated annually.

Above ground crossing points should be examined at least once per year for condition of
supports and associated structures, including paintwork and protective wrap, and refurbished
where necessary.