On April 6, 1994, a unit operator was conducting
rounds of the coker unit when he observed a leak coming from the
mechanical seal of the heavy gas oil pump of coker unit #1. The operator
decided to seek assistance; the head unit operator and six or seven
unit operators responded. The operators placed water and steam on the
leak to suppress the vapor from the seal. The head unit operator decided
to shut down the pump and transfer the product to the secondary pump.
As the operator shut down the primary pump, the mechanical seal blew,
causing a vapor cloud to generate from the seal. The operators continued
to put steam and water on the seal and isolated the pump from the pipe
line. The remaining product in the pipe line leading to the primary
heavy gas oil pump vaporized, leading to the dispersion of the vapor
cloud. The operators who responded were wearing bunker gear and several
wore emergency respirators. Those with respirators isolated the pump
from the pipe line by closing the suction and discharge valves. The
operators who were not wearing emergency respirators stationed
themselves upwind of the vapor cloud and put water on the cloud;
however, the wind changed direction several times, exposing unprotected
operators to vapors. Employees #1 and #2, two unprotected operators who
responded to incident, were brought to Hospital to
be treated for inhalation of hydrocarbons. Employee #1 was hospitalized.
Source: OSHA
Source: OSHA