NEAR MISS - Equipment Damage & Failure
An LPG response team was activated to a site to flare down an LPG stationary tank containing a mix of LPG and anhydrous ammonia. The response team used three liquid flare pots to conduct this work over a three-day period. Upon finishing the task, it was noted that the LPG hoses connected to the liquid flare pots sustained heat-affected damage to the last three to four feet; the hoses were considered a total loss.
Also, one liquid flare pot was taken out of service due to sustaining a leak during the liquid flaring operation through the gas fitting union on the flare pot.
What caused it
The heat-affected damage on the hoses was due to inadequate hard pipe being used, leaving the liquid flare to the transfer hoses. Because the flame is closer to the ground, temperatures were substantially higher than when using a vapour flare. Only eight feet of hard pipe was used with each liquid flare pot during this event.
Additionally, when the leaking liquid flare pot was inspected and pressure tested, it was found that the gas fitting union leaked at 15 psi. The union was tool tight when disassembled, brushed clean and reassembled, then pressure tested to 300 psi. The threads may have had a burr in them, causing the leak.