(188a) Quench Oil Isolation to Prevent Incidents

QUENCH OIL ISOLATION TO PREVENT INCIDENTS

Norman Wilhelm
Process Engineer
Equistar Chemicals, LP
Abstract:
Quench oil can present many challenges when it comes to isolating and
clearing equipment for maintenance.  Ethylene
plants designed to crack liquids contain equipment in quench oil service that
requires frequent maintenance such as feed preheaters, dilution steam
generators, process water preheat, quench oil pumps and filters, and quench
fittings.  Quench oil presents challenges
to operators during LOTO and clearing due to its physical properties; it can contain
solids, is viscous, and has a high pour point. 
Failure to isolate and clear this equipment correctly has led to
significant process safety incidents and injuries.  This paper will review quench oil physical
properties, highlight incidents related to quench oil loss of containment,
discuss criteria for selecting isolation valves, and make recommendations for
design best practices.