When natural gas enters a compressor station, it first passes through scrubbers and filters. These processes are intended to remove waste byproducts from the gas before it is compressed and continues to flow through the pipeline. Wastes can be water condensates or heavier hydrocarbons from the natural gas. Extracting and removing this compressor liquid waste further refines the gas and helps it to flow more smoothly through the pipeline.
Scrubbers and filters that capture liquid waste and unwanted particles route waste liquids to a storage tank. The wastes are collected in one or several tanks depending on the size of the remote station. As a waste tank fills, tank trucks are typically scheduled for tank emptying operations. As these wastes are hazardous materials, the waste holding tanks are classified as Class 1, Div. 1 areas.
Level measurement challenges and considerations
The liquids in the waste storage tanks often separate and form an interface, which can be difficult to measure without proper level instrumentation specifically designed for such an application. Measurements for both total level and interface levels between the condensed hydrocarbons and condensed water are typically required.
Since the storage tanks contain hazardous material, preventing overflow and accidents is crucial. Tank level monitoring can be provided with overflow control and alarm systems or shutdown pumps when level falls below the specified low level. Level instrumentation used in this application should be able to withstand the corrosive conditions of hazardous materials and have the capacity to detect level with great precision and accuracy.
Level measurement solutions
Magnetrol has produced level measurement solutions for waste compressor liquid storage:
- For point level:Echotel Model 961/962 ultrasonic level switches or Thermatel TD1/TD2 thermal dispersion switches
- For continuous level: Eclipse Model 706 guided wave radar transmitter or Jupiter JM4 magnetostrictive transmitter
- For visual indication: Atlas or Aurora magnetic level indicators