Remote Instrument Buildings (RIBs) Layout and Spacing

This article is about technical requirements of Layout and Spacing of Remote Instrument Buildings (RIBs) in petrochemical plants.

Remote Instrument Buildings (RIBs)

Remote Instrument Buildings (RIBs) are structures located away from the main process plant that house instruments and control systems used to monitor and operate the plant. RIBs are often used in large-scale industrial facilities, such as chemical plants and refineries, where it is not practical to locate all instrumentation and control systems within the main plant area.

RIBs typically house a variety of equipment, including distributed control systems (DCS), programmable logic controllers (PLC), and field instruments such as sensors and transmitters. The building itself may also include environmental control systems to maintain a stable temperature and humidity level, as well as fire suppression and security systems.

The design and layout of RIBs must take into account the specific needs of the plant being monitored. The location of the RIB must be carefully selected to ensure easy access for personnel and equipment, while also providing a safe distance from the main plant area. RIBs may also need to be designed to withstand harsh environmental conditions, such as extreme temperatures, high winds, and seismic activity.

Layout and Spacing of Remote Instrument Buildings (RIBs)

Spacing for remote instrument buildings (RIBs) is shown in Tables I-A and II-A and outlined below. Remote instrument buildings should be located a minimum of 60 meter from the property boundary. Locate remote instrument buildings at the perimeter of the unit battery limits so that access to the structure can be gained without traversing a process unit.

Consideration should be given in locating the structure to minimizing exposure from heaters and fired equipment, vessels containing a large inventory of toxic or flammable liquids, vents, or flares. Exposures to large rotating equipment containing hydrocarbons, such as compressors, expanders, and pumps operating above 260 °C or in excess of 3.45 Mpa gage, should also be minimized.

Provisions in Paragraph 7.9 shall apply to location of purging air intakes if RIBs are pressurized to
maintain appropriate area classification.

Single-Unit Remote Instrument Buildings (RIBs)

1. In addition to the requirements above, remote instrument buildings serving a single process unit
2. should be located at least 60 m from nonassociated process equipment (not a part of the unit being
3. served) that contain flammable or combustible liquids and/or vapors that would potentially form a vapor cloud upon release. Spacing of less than 60 m is acceptable if the blast-resistant construction criteria for control rooms is utilized. The 60 m spacing is required in order to protect the RIB from a blast in an adjacent unit that could destroy the RIB and adversely affect a safe shutdown of the unit served by the RIB. The 60 m spacing requirement also provides greater reliability of the unit in regard to operation after a blast in an adjacent unit.
4. Single-unit RIBs should not be clustered in the same general location and should be located at least 15 m from any process equipment containing flammable liquids or vapors. The 15 meter spacing from equipment containing hydrocarbons is provided for fire exposure considerations.

Multi Unit Remote Instrument Buildings (RIBs)

1. In addition to the requirements above, remote instrument buildings serving more than one unit should be located at least 150 m from any process equipment containing flammable or combustible liquids and/or vapors that would potentially form a vapor cloud upon release. As in single-unit instrument buildings, spacing less than 150 m is acceptable if the blast-resistant construction criteria for control rooms is utilized. The 150 m spacing is required in order to protect the RIB from a blast that could destroy the RIB and adversely affect the safe shutdown of the units served by the RIB. The 150 m spacing requirement also provides greater reliability of the units served by the RIB in regard to operation after a blast.
2. Multi-unit RIBs should not be part of administration buildings, laboratories, or any other nonrelated structure. Where it is deemed absolutely necessary to combine a multi-unit RIB and a nonrelated structure, the RIB must be separated from the structure by a 3-hour rated fire wall without directed access or any other penetrations through the fire wall.
3. Multi-unit remote instrument buildings should be located at least 30 m from any process equipment containing flammable liquids or vapors that would not form a vapor cloud upon release. The 30 meter spacing requirement to all equipment handling hydrocarbons is provided for fire exposure considerations. Also see OFFSITE TANK STORAGE.

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