Wastewater separators
Wastewater separators handling hydrocarbons should be spaced at least 30 m from process unit equipment handling flammable liquids and 60 m from heaters or other continuous sources of ignition. Preferably, wastewater separators should be located downgrade of process equipment and tankage. These criteria shall also be applicable to the sea water cooling water discharge structure.
Blowdown Drums
Blowdown drums are used for liquid relief of flammable and toxic fluids in emergencies and are not usually installed when a suitable pressure-relieving system and flare are provided. When used, blowdown drums should be 30 m minimum from process unit battery limits and 60 m from storage tanks and other refinery
facilities.
Fire Training Areas
Fire training areas are ignition sources when in use. Because of the smoke produced, they can also create a nuisance for the refinery and neighboring facilities. Fire training areas should be 60 m from process unit battery limits, main control rooms, fired steam generators, fire pumps, cooling towers, and all types of storage tanks. They should also be at least 75 m from property boundaries, administration, shop, and similar buildings; and from the main substation.
Layout requirements for fire equipment and monitors is specified in the Fire Protection Systems Standard.
Ethylene Vaporizers
The layout and spacing of ethylene vaporization facilities shall be generally in accordance with NFPA 59A, Section 214 and Chapter 5 for LNG Vaporizers.
Offsite Facilities | Safety Considerations for Plant Layout Levels
Compressed and Liquefied Gas Storage
a. Portable Gas Cylinders
Supplies of various industrial gases, when located in process units, should be placed where vulnerability to fire exposure is at a minimum. Installations involving multiple cylinders of flammable or toxic liquids should be located as close as practicable to the unit battery limit, at least 7.5 m from hydrocarbon equipment, and as near to the plant gate as practicable to avoid truck traffic near process areas. Fire fighting access shall be provided. Bulk storage of cylinders shall be located in a remote offsite area, a minimum of 60 m from process units.
b. Refrigerated Containers of Industrial Gases
Bulk liquefied oxygen, chlorine, and nitrogen each present significant problems to overall plant safety. Reactive and oxidizing gases such as oxygen and chlorine in refrigerated containers shall not be located within process plant battery limits. Locate storage containers on periphery of the entire
process area. Remote location minimizes the significant hazard of having tank trucks of refrigerated reactive and oxidizing liquid gases entering hydrocarbon process unit locations. Arrangement of bulk oxygen supplies shall be in accordance with NFPA 50 and bulk chlorine supplies in accordance with NFPA 43C. Liquid nitrogen containers should be located in areas relatively free of exposure to fire and mechanical damage in accordance with vendor recommendations.
Fuel Dispensing Facilities
Fuel dispensing facilities for gasoline, diesel, or compressed natural gas shall be located a minimum of 50 m from the process areas or potential ignition sources. Process drains shall be provided for the flushing of any spilled liquids. Underground storage tanks shall meet be double lined and be provided with continuous monitoring for early detection of leaks as required in section 10.7, Underground Storage Tanks.
Flammable fuel tanks shall meet spacing, grounding, electrical, and fire protection requirements as specified for flammable storage tanks.
API RP 1637 and 1637A Equipment Marking Color-System for Product Identification At Servicing and Distribution Terminals shall be used as a guideline for labeling.
Safe Assembly Areas
Emergency Control Center
Emergency facilities shall be provided that include an emergency control center. The control center shall be specially a designated room in a safe area, accessible from the public roads and with space around it for emergency service vehicles. The safe area shall be determined by considering the units and operations of the facilities, and studying scenarios of the potential hazards and of their development.
Assembly points
Assembly points shall be designated and assigned in safe areas at least 100 m from the plants. The number, size and specific locations of assembly points shall be determined by studying the scenarios and the potential hazards. Evacuation routes to assembly points and alternate assembly points shall be
provided. A control room should not be used either as the emergency control center or as a refuge room.
Roadway
The facility shall have a road around the periphery with access to the public roads at a minimum of two points. The vulnerability of the works road system to blockage shall be as low as possible. The turning circles shall be a minimum of 15 m to accommodate emergency response equipment.
Smoking Zones
For facilities requiring smoking zones, smoke shelters shall be located in an unclassified area and a minimum of 15 m from any process unit, flammable or combustible storage tank, chemical or material storage area. Shelters shall be constructed of non-combustible materials, open on one side, and louvered
side panels for ventilation. Floor shall be concrete or gravel. A portable fire extinguisher shall be provided in the shelter area.