Fluid Components International FLT93L Series FlexSwitch thermal flow switch

The Fluid Components International FLT93L Series FlexSwitch thermal flow switch provides process relief valve leak monitoring during the petrochemical process.

The product accurately monitors the pressure relief valves for escaping flow with a thermal dispersion technology flow sensing switch/alarm.

In this application, an inline configuration is placed on 0.5″ and 1″ (DN15 and DN25) diameter pipes. The switch detects leaking or seeping gas in the lines to alert the engineer to overpressurisation. It issues a programmed alarm during such events. For the system to work properly, the product must detect low flows and yet avoid issuing false alarms that could seriously impact plant operations.

The switch offers a number of advantages for overpressure monitoring. Not all gas flow sensing technologies are able to detect the required low levels of leaking or seeping gas, which can cause an overpressure event that puts plant safety at risk. The opposite situation also can occur where some alternative flow sensing technologies issue nuisance false alarms frequently, disrupting plant operations.

Beyond accurate monitoring, the switch offers a number of other advantages in this application. It is easy to install and set up. The voltage output allows the user to see into the process and accurately set the desired trip point. Flexible dual relays are settable by the plant technician for any combination of flow and/or temperature alarms.

The product’s flow accuracy is ±2% of the setpoint velocity over a ±28°C temperature range. Repeatability is ±0.5% reading.

A wide selection of standard and custom process connections can be provided. The electronic control circuit can be integrally mounted with the sensing element or it can be located in a remote location. The standard enclosure is a coated aluminium alloy and is rated for NEMA Type 4X (IP67) environments. Global agency approvals for Ex installations are provided. It is SIL 2 rated for reliability.