In the demanding environment of petrochemical plants, minor inefficiencies can lead to major operational and financial consequences. A valve leak, specifically, can result in the release of hazardous chemicals, posing severe risks to worker safety and significant losses in energy efficiency. If left unaddressed, these leaks can result in costly downtime and potential regulatory penalties, impacting the plant’s operations.

Understanding how to effectively mitigate the negative consequences of a valve leak, and implement a viable solution is, therefore, essential to ensure that the plant operates
as efficiently as possible.

By Angelica Pajkovic and Roberto Araujo – Teadit

The Challenge

A large petrochemical plant faced significant challenges due to leakages in the superheated steam valves within its Ethylene unit.

In ethylene production, which involves high temperatures and pressures, valves are crucial for ensuring the precise control of process variables to optimize yield and maintain operational safety. These valves manage the flow of feedstocks, control the temperature and pressure within reactors, and isolate sections of the system for maintenance and safety purposes.

In this case, the traditional die-formed graphite ring packing used to seal the valve proved inadequate under the highpressure conditions required for production. The use of the unfit packing led to leaks that escalated maintenance costs and posed severe safety risks.

The leaking steam also had economic consequences, as the method used to create the steam included burning hydrocarbon (typically, natural gas or fuel oil), which is costly to produce.

While the plant’s preventative maintenance program involved regular replacement of the packing rings, this action failed to resolve the issue. The next consideration was the costly and extensive process of replacing all 1,520 affected valves. Faced with the prospect of a disruptive valve replacement process, the large petrochemical plant sought a more effective solution.