Platforms are required at drums for access to valves, instruments, blinds, and maintenance accesses.
Following figure shows platform arrangement at horizontal drum.
Following figure displays the arrangement for vertical drum.
For tall vertical drums, platforms are usually circular and supported by brackets attached to the shell of the drum.
Platforms at horizontal drums are usually rectangular and are supported by brackets attached to the concrete piers supporting the drum or trunions attached to the shell of the drum, or by structural steel supported from the grade.
Drums located in structures, if size permits, use the structure floor for access to controls.
Top head platforms on horizontal and vertical installations are supported by trunions attached to the vessel heads.
Generally access to free standing drum platforms is by ladder. Typical drum platform arrangement is shown below.
Platform elevations for drums are set by the items that require operation and maintenance.
On tall vertical and high elevated horizontal drums, the platform elevations are determined by maximum ladder run of 30 ft (9150 mm).
Following drawing illustrates horizontal drum platform and ladder elevation requirements. Platform floor space requirements are dictated by operator access to controls, instruments and maintenance accesses.
Following diagrams show platform floor space requirements for horizontal and vertical installations.
For tall vertical drums, platforms should be arranged as per tower guidelines. Following drawing shows a horizontal drum platform arrangement that was designed using the guidelines in this chapter.