Section 6: Fire Safety Guidelines for Roof Top Central LPG Container Installations,
of Chapter 11: Fire Safety Guideline for LPG Installation,
of the UAE Fire and Life Safety Code of Practice (2011)
6.1 General Description
6.1.1 This part of the LPG guideline is intended for LPG containers installed on roof top of buildings. It provides separation distances, allowable quantities, construction material, detection system, suppression system, fire fighting requirements and other system configurations in relation to roof top installation.
6.2 System Design and Requirements
6.2.1 Central tank LPG is preferred to be installed underground or above ground locations rather than roof top locations.
6.2.2 LPG containers are not allowed to be installed on the roof of high-rise buildings. However, considering the UAE’s building and space trend, it is permitted on roof subjected to strict compliance with Code and regulation requirements.
6.2.3 The building shall be of Type I, 443 or 332, or Type II, 222, construction as specified in NFPA 220, Standard on Types of Building Construction. For other types of construction, the total allowable quantity shall be reduced to 1000 gal.
6.2.4. The LPG container shall always be filled by two operators, one at the controls of the vehicle supplying LPG and another at the controller of the container.
6.2.5. Containers shall be installed in external locations only.
6.2.6. Fill line and connection shall be located entirely outside the building.
6.2.7. Containers shall be installed on a level surface.
6.2.8. The container shall be secured to the building structure.
6.2.9. All valves and controls shall be easily accessible and have sufficient space for maintenance.
6.2.10. All liquid and vapor withdrawal openings that are 3.2cm or larger shall be equipped with internal valves.
6.2.11. The internal valves shall be remain closed except during periods of operations.
6.2.12. Internal valves shall be equipped with remote closure and automatic shutoff through thermal activation.
6.2.13. A positive manual shutoff valve shall be installed as close as practical to each internal valve.
6.2.14. All liquid and vapor inlet openings shall be equipped with a backflow check valve where applicable installed with a positive manual shut off valve installed as close as practical to the backflow check valve.
6.2.15. Insulation of container shall be able to limit the container to not over 427 degree Celsius for a minimum period of 50 minutes.
6.2.16. The support of the container shall be designed to the same seismic criteria as the building.
6.2.17. The roof which the container is located shall be able to support the weight of the container filled with water.
6.3. Safe Distances and Allowable Quantities
6.3.1. Containers shall be located in areas where there is free air circulation, at least 3m from building openings such as windows and doors. It shall be at least 6.1m from air intakes for air-conditioning and ventilation systems. Distance between container and the edge of building can be reduce to 3m if the distance between containers is increased to 7.6m
6.3.2. Fill connection shall be located at least 2.4m above the ground.
6.3.3. The total allowable quantity to be installed on a roof top shall be 2000gal. Total quantities above 2000gal shall require risk analysis and emergency planning based on NFPA 58 as well as permission from Civil Defence prior to planning of such installations.
6.3.4. If more than one container (e.g. 2 numbers of 1000gals), the distance between the container(s) shall be in accordance to the Table 11.1.
6.4. Piping and Connections
6.4.1. If the container location is higher than 7m form the ground, or the filling hose cannot be monitored by the operator in its entire length, the container shall be a filling line constructed to withstand liquid transfer and shall have the following appurtenances:
i. Filler valve with back check valve.
ii. Filler valve cap.
iii. Two control valves.
iv. Hydrostatic relief valve.
v. Venting line.
6.4.2. The liquid and vapor fill connections shall be conspicuously marked or labeled.
6.4.3. No liquid phase LPG shall be allowed to be piped into the building.
6.4.4. LPG pipe installation shall not be permitted in the following areas.
i. In the ground under concrete flooring within the building.
ii. Under building foundation.
iii. Within lift shafts and cavity walls.
iv. In compartments or ducts dedicated for electrical switchgears, transformers or generators.
v. In refrigeration chambers, cold rooms, air handling unit rooms and ventilation or air-conditioning ducts.
vi. Adjacent to pipes and vessels containing flammable, oxidizing, corrosive and other hazardous materials.
6.4.5. Proper pipe sleeves shall be installed for LPG pipes running in enclosed, unventilated areas or basement floor and at least one end exposed directly to the exterior open safe space. Pipe sleeves and gas leak detectors shall be located such that it facilitates detection of gas leak effectively.
6.5. Pipe Material
6.5.1. LPG fill line shall be seamless steel to ASTM A53, A106 GrB, API 5L GrB schedule 80.
6.5.2. Below ground Distribution pipe work shall be seamless steel to ASTM A53, A 106 with Denso /Bitumen Tape wrapping or HDPE/MDPE SDR11.
6.5.3. Above ground distribution pipe work shall be Seamless Carbon steel Pipe to ASTM A53, Grade B.
6.5.4. Above Ground copper Pipe shall confirm to ASTM B280/ BS 2871.
6.5.5. Final connections to equipment shall be Flexible Hose
6.6. System Shut- Off Configuration
6.6.1. Gas leak detectors shall be provided in areas where there is insufficient ventilation and where accidental accumulation of LPG vapor could occur.
6.6.2. The gas leak detector shall be linked to the exhaust fan and the emergency shut-off valve as well as the fire alarm where applicable.
6.6.3. A remote shutdown station shall be provided within 4.6m of point of transfer.
6.6.4. At least an additional remote shutdown station shall be installed not less than 7.6m or more than 30.5m from the transfer point.
6.6.5. Kitchen suppression system, if installed, shall be linked to the LPG cylinder installation in such a way that the activation of the system shall automatically shut off the supply of LPG to the kitchen. See Figure 11.1 of Annex A for the connection between LPG shut-off, gas leak detection, kitchen exhaust, and kitchen suppression system.
6.7. Protection and Fire Fighting Requirement.
6.7.1. A product release prevention and incident preparedness review may be required to be submitted by the owner, operator or the authorized person if requested by Civil Defence. The review shall be an evaluation of the total Liquefied Petroleum Gas control system, such as emergency shut-off and internal valves equipped for remote closure as well as automatic shut off through thermal actuation.
6.7.2. The location of the container shall have at least 2 fixed protected stairs to reach it.
6.7.3. Wet standpipe system equipped with landing valves shall be provided inside the protected staircase.
6.7.4. Fire engine accessway and other means of access for fire fighting access shall be provided. Emergency controls shall be conspicuously marked and the controls shall be located so as to be readily accessible in emergencies.
6.7.5. Water spray fixed system or monitors shall be used and shall be automatically activated by fire alarm.
6.7.6. The water spray fixed system or monitors shall be able to be activated manually and shall be positioned so as to wet all surfaces of the container exposed to fire.
6.7.7. NFPA 58 and NFPA 54 shall be referred for other relevant requirements concerning roof top LPG installation.
6.8. LPG Storage Tank
6.8.1. Containers shall be designed, fabricated, tested and marked (or stamped) in accordance with one of the following:
i. Regulations of the U.S Department of Transportation (DOT), the “Rules for the Construction of Unfired Pressure Vessels”, Section VIII, Division 1
ii. ASME Boiler and Pressure Vessel Code
iii. API-ASME Code for Unfired Pressure Vessels for Petroleum Liquids and Gases.
iv. BS5500 or EN 12542/EN 14075
v. AD Merkblatt Standards.
6.8.2. Heating or cooling coils shall not be installed inside storage containers.
6.8.3. Each tank shall be equipped with Magnetic Level Gauge , fixed level Gauge , Safety Relief Valve , Shut off Valve , Pressure Gauge , Multi Valve , Back flow Check Valve , Drain Valve , Excess Flow Valve and other related accessories.