Operations & Maintenance
Critical Connections Demand Certainty
Figure 1. During tightening, hydraulic pressure load within a bolt should be uniformly and accurately applied to avoid gasket damage and other issues that can create leakage Common knowledge dictates that planning ahead ensures effective results, regardless of the task…
Control Valve Selection: True Cost Savings Are Available
New safety and environmental regulations, longer plant uptime and changes in maintenance practices have created new requirements across the chemical process industries (CPI). Among the plant equipment affected by these changes are control valves, since they are used in numerous…
Protecting Against Compressor Pulsations
Pressure variations resulting from the oscillatory flow patterns found in positive-displacement machinery, especially reciprocating compressors, are referred to as “pulsations.” Found in both liquid- and gas-handling systems, pulsations are a common phenomenon in the chemical processing industries (CPI). Operational problems…
Waterhammer In Condensate Return Lines
There is a temptation that steam design engineers find difficult to resist — to put condensate from high-pressure (HP) steam mains directly into the low-pressure (LP), pumped condensate-return (CR) mains. After all, the CR main is so convenient — it…
Lubricating Rotating Machinery
Lubricants in rotating machines reduce friction and wear, dissipate heat, protect surfaces, keep out foreign contaminants and remove wear particles. Commonly used liquid lubricants fall into two main categories: mineral (petroleum-based) oils and synthetic oils. Mineral oils…
Ten troubleshooting tips
Good troubleshooting skills are invaluable in chemical engineering practice. While their value is clearly gleaned from the impact they have on plant performance, it is also a reflection of the intangible process of learning them. Last month, at the AIChE…
Comparing petrochemical plant aging
The massive buildup of new petrochemical capacity in the Middle East and Asia has been well documented, and its effect on future supply-demand much discussed. But a look at the average ages of plants in different regions in the years…
Feature Report: The Number One Problem in a Steam System: Water Hammer
Water hammer — a high-pressure surge or wave created by the kinetic energy of the moving liquid — is not only a system issue, but primarily a safety concern. Understanding the nature and severity of water hammer in a…
Maintenance and Repair of Glass-Lined Equipment
A customized inspection and maintenance program will minimize operational and performance problems with glass-lined equipment Glass-lined steel equipment is used in a wide range of chemical processes that involve harsh chemicals, including the production of pharmaceuticals, specialty chemicals, agricultural products…
An alternative to cranes for moving heavy equipment
As the demand for productions plants with “mega” capacities grows, one challenge facing engineering contractors has been how to move the very large vessels, columns, heat exchangers and other equipment as it's being constructed. Now companies that fabricate and assemble…