Improper valve operation blamed for terminal fire in Jaipur, India
Volume 25, No. 2
Improper valve operation in transferring product by pipeline caused a massive vapor explosion and resulted in an 11-day fire that destroyed an oil terminal in Jaipur, India, in October, a report issued by the Indian government states.
"The immediate cause of the accident was the non-observance of normal safe procedure involving sequence of valve operation in the line up activity and an engineering design which permitted use of a 'Hammer Blind Valve,' a device which is used for positively isolating a pipeline," the report issued by the Indian Ministry of Petroleum and Natural Gas states.
Only six of the 11 people killed in the incident worked at the destroyed terminal. The rest were employed by neighboring industrial facilities within the two kilometer blast zone. Forty-five people were injured in the incident.
Industry sources compare the Jaipur explosion to mammoth industrial vapor cloud blasts that destroyed the Buncefield oil deport in the U.K. in December 2005 and the Bayamon, Puerto Rico, oil terminal incident only seven days before the Jaipur disaster. (See "Danger Island," in IFW's Jan.-Feb. 2010 issue.)
"The Jaipur incident was the first of its kind in India and the third one reported globally," the Indian report states. "Loss of containment in terms of time and quantity was never considered a 'credible event' and accordingly not taken into account in 'hazard identification,'"
According to the report, a shift officer and three operators were manning the Indian Oil Corporation's POL (Petroleum Oil Lubricants) terminal at Sanganer in Jaipur the evening of Oct. 29. The crew prepared to transfer kerosene and motor spirit (MS) to the nearby BPCL Terminal, considered to be a routine operation.
"Kerosene was 'lined up' (pipeline made through) first and thereafter the operating crew proceeded to prepare the MS tank (tank 401-A) for pumping to the BPCL installation," the report states. "In the process of lining up the MS tank, at about 6:10 p.m., a huge leak of the product took place as a jet of liquid from the 'Hammer Blind Valve' on the delivery line of the tank leading to the MS pump."
The design of the valve allowed a large area at the top to be open when the valve position was changed, the report states. MS gushed through this open area because another valve connecting to the tank was open at the same time.
Vapor generated by the MS spill soon overwhelmed and incapacitated the operator conducting the line up operation. The shift officer, who was nearby, tried to help the operator but was soon overcome himself and removed in a semi-conscious state.
"The second operator, who was incidentally in the canteen at the time, also rushed to the spot, but he was also completely overpowered by the strong MS vapors and liquid and could not be rescued," the report states. "The third operator on the shift, who was supposed to be on site, had earlier left for home on some personal work and was thus not available to initiate any rescue or mitigating steps."
Leaking vapor continued unabated, the report states. By the time senior staff and civil authorities could reach the site, the entire installation had been engulfed in flammable vapor.
"After about an hour and 15 minutes of the leak having started, there was a massive explosion followed by a huge fireball that covered the entire installation," the report states. "It is estimated that in this one hour and 15 or 20 minutes of uncontrolled leak, about 1,000 tons of MS could have escaped out, which would have generated enough vapor to cause an explosion with the equivalence of 20 tons of TNT."
The fire following the explosion soon spread through 10 other storage tanks containing an estimated 60,000 kiloliters (nearly 16 million gallons) of MS, kerosene and diesel, truck loading racks to deliver these products and the pipeline pumping facilities. Management of the terminal decided to allow the fires to burn out to avoid further risk to personnel.
"Non-availability of a self contained breathing apparatus (SCBA) and fire suits immediately left the entire response team as mere helpless spectators in preventing the incident," the report states.
Overall, the government report determined three root causes for the Jaipur disaster:
- Absence of site specific written operating procedures,
- Absence of devices that could have stopped the leak from a remote location, such as a motor operated valve on the side of the tank,
- Insufficient understanding of the hazards, risks and consequences of the product involved.
"The lack of back up for emergency shut down from the control room, the absence of company officials in the control room and lack of any emergency response for a long period allowed leakage to go uncontrolled resulting in the massive vapor cloud explosion," the report states.