FCI's FLT93L Flow Switch aims to enhance safety for natural gas facilities

  • September 08, 2017
  • FCI - Fluid Components International
FCI's  FLT93L Flow Switch aims to enhance safety for natural gas facilities
FCI's FLT93L Flow Switch aims to enhance safety for natural gas facilities

September 8, 2017--Process and plant engineers responsible for the safety of natural gas fractionation processes will find the FLT93 Series Flow Switch from Fluid Components International (FCI) provides a solution to relief valve leak monitoring that keeps their facilities safe.

NGL fractionation process facilities separate ethane, propane, butane and other heavier hydrocarbons from mixed NGL streams. Multiple trains and columns are typically used in a fractional distillation process, with relief valves installed as critical safety protection devices that release when needed to prevent pressure from building within the process.

A flow switch is typically installed after the pressure relief valve and alarms if there is flow. For the NGL fractionation process to work efficiently and safely, the operation requires early and reliable indication when a relief valve leaks or lifts during an overpressure situation.   

Should the flow switch alarm due to gas being released through the relief valve, it indicates via a dry contact that there is an event in progress.  The facility’s staff then responds by taking the appropriate corrective action to resolve the event.

FCI’s inline FLT93L Flow Switch is ideal for relief valve leak monitoring in natural gas fractionation applications.  It is a thermal dispersion flow/level/temperature switch that was designed based on FCI’s more than 50 years of flow/level/temperature switch applications experience. 

Designed with an all-welded thermal sensing element, the FLT93L Switch includes an advanced electronic control circuit, which is field configurable to satisfy any combination of application requirements.  The thermal sensor in this switch is suitable for both gases and hydrocarbon-based liquids.

The FLT93L Switch’s voltage output allows the user to “see” into the process and accurately set the desired trip point.  The delta range between the switch’s two RTDs provides a span for setting the switch trip points.  These dual relays are settable by the plant technician for any combination of flow, level and/or temperature alarms.

With a standard flow accuracy of ±2% of the setpointvelocity over a ±50°F [±28°C] temperature range, the switch meets the needs of this application. Its repeatability of ±0.5% reading also is satisfactory for operation in natural gas fractionation relief valve leak monitoring. 

The FLT93L Switch also is SIL-2 rated.  The complete instrument offers Ex agency approvals:  FM, FMc, ATEX, IECEx, Inmetro and TR CU.  Integrated with the FLT93 Switch’s thermal flow sensor is a fail-safe, dual alarm (SPDT) control circuit for field flexibility and user friendliness. 

The control circuit’s dual independent heavy duty 6A SPDT relays provide the multiple alarm combinations. They can be set for flow rate and temperature, high flow and low flow, point level and temperature, flow rate and low liquid level, three-phase interface or fail-safe flow, level or temperature.


About FCI

Fluid Components International is a global company committed to meeting the needs of its customers through innovative solutions to the most challenging requirements for sensing, measuring and controlling flow and level of air, gases and liquids.

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