Leak Detector and Sensor Testing

Leak Detector And Sensor Testing

Best practice for Leak detector testing is to test once a year for all underground pressurized lines regardless of line configuration. GEA technicians simulate a 3 gallon per hour leak to ensure the line is protected from a catastrophic failure.

Each sensor is tested by a GEA certified technician to make sure it alarms when activated. It some cases sensors a submerged in liquid to initiate the alarm condition; the sensor is then dried out then replaced in its proper position. Where applicable tank sensors will also be checked to make sure it is operating properly, all sensors are tested and placed in positions recommended by the sensor manufacturer.
Each sensor test will be documented and where needed sensors will be replaced if found to be operating incorrectly. GEA technicians will test the sensor systems by replicating a leak and confirming an alarm.

Line leak detectors are a necessity on petroleum pumping systems. There are generally two types; MLLD (Mechanical Line Leak Detection) and ELLD (Electronic Line Leak Detection). The MLLD conducts a leak test as the pump is turned on and the MLLD conducts a leak test while the pump is off. The ELLD system is based upon principles of pressure decay and constant pressure. GEA technicians test downstream of LLD to solenoid in dispenser, between check valve at pump and solenoid in dispenser and downstream of LLD valve to solenoid in dispenser.

EPA standards in the United States declares ATGS must be able to detect a leak no larger than 0.2. gallons per hour with certain probabilities of detection and of false alarm. Some ATGS can also detect a leak of 0.1 gallons per hour with the required probabilities. Best practice for Leak detector testing is to test once a year for all underground pressurized lines regardless of line configuration. A 3 Gallons Per Hour leak is simulated by a GEA technician to ensure the line is protected from a catastrophic failure. Even a leak at .2 gallons per hour equates to 4.8 gallons a day and almost 1,800 gallons a year; besides the negative impact on the environment, small leaks can be expensive!

Most systems have an automatic tank gauge monitoring device (ATG), this device actually monitors leak detection. However, no systems are without their problems; testing to make sure the leak detection system works is a standard practice. GEA Technicians often tie this service in during routine maintenance generally part of an overall site survey done once a year.

How does the leak detection method work? This method uses automated processes to monitor product level and inventory control. Overfill alarms are often a part of automatic tank gauging systems (ATGS). Overfill alarms use probes installed in the tank to activate an alarm when the tank is either 90 percent full or within 1 minute of being overfilled. Either way, the alarm should provide enough time for the driver to close the truck's shutoff valve before an overfill happens. Alarms must be located where the driver can see or hear them easily.
Overfill alarms work only if they alert the driver at the right time and the driver responds quickly. Many deliveries are made at night when the facility is closed. You don't want to turn off your alarm when you turn off the office lights. Also remember, water around a tank may hide a leak by temporarily preventing the product from leaving the tank. To detect a leak in this situation, the ATGS should be capable of detecting water in the bottom of a tank.