A minimum of one meter distance has to be specified between all oil system components to allow operator access, and to optimize system reliability. Access to all major components is essential to allow operator intervention to switch over to spared system components without the risk of unscheduled trips of critical equipment (un-spared).
(Construction of auxiliary equipment console should be reviewed to ensure stiffness)
Having confirmed an acceptable component sizing and selection, the console layout and arrangement of components must be reviewed. Methods of review incorporate either a review of outline drawings of the proposed arrangement, or a model review, or a CAD 3D drawing review. Many vendors and users found that models or CAD 3D drawings aid greatly in the understanding and reviewing of maintenance accessibility and layout considerations.
Console construction
Auxiliary equipment consoles or modules house most of the components present in the auxiliary systems. Their construction should be reviewed to ensure proper stiffness and facilities for installation on site. Many horizontal consoles are constructed in a flexible manner that can result in bending or excessive pipe strains being introduced into during shipment or at installation.
It is suggested that full length cross members be positioned as a minimum under pumps, coolers and filters on the equipment baseplate. If the baseplate is to be grouted in the field, grout and vent holes should be specified, and reviewed for accessibility to pore grout when equipment is installed on the baseplate. Since equipment must be maintained and calibrated while the auxiliary system is in operation, it is important to provide ample personnel space such that this equipment can be maintained safely and reliably without damage to surrounding components.
A rule of thumb is to provide approximately one meter of space around the components for accessibility. Note that this is with the utility lines installed. The review of equipment on a model, CAD 3D drawing or an outline should be made considering installation of all utility lines that will be installed in the field.
Online testing
Considering that many components (pumps, drivers, coolers, filters, control valves, instrumentation) will be tested and calibrated with equipment in operation, accessibility for this operation must be considered.
In addition to reviewing the vendor manufactured skids, the placement of all skids in the field must be reviewed for accessibility. Consideration of the skid arrangement only to be complicated by installation against a column or wall in the field will not obtain the objectives of total accessibility. Care should be given to the routing of all utility (conduits, steam lines, water lines) supply lines in order to maximize accessibility to the critical equipment auxiliary systems.
Considerations for component disassembly
All components must be able to be disassembled quickly, easily and safely while the unit is operating in the field. To meet this requirement, sufficient space around the auxiliary console must be available for such exercises as cooler bundle removal, filter cartridge removal and auxiliary or main driver removal.
In addition, consoles are frequently installed in congested areas, and lifting arrangements should be reviewed beforehand to confirm that components can be removed in a safe and easy manner.
Easy access for maintenance
Consoles that are crowded and do not allow easy access are often ignored by operators and not fully understood in terms of system function. Critical unit shutdowns of a steam turbine driven pump can be experienced, when the local trip lever is accidentally hit due to limited space being available when the personnel are climbing on the console in the course of normal maintenance activities.
This best practice has been used since my design days for a major machinery vendor (late 1960s) to ensure optimum oil system and corresponding critical machinery train reliability. This approach continues from that time to ensure + 99.7 percent reliability on all equipment trains.
