Leak detection is one of the more fascinating aspects of plumbing that uses all sorts of technological innovations to detect and locate leaky pipes. These methods are diverse and come with their own pros and cons, so we’re offering a two-part guide to the general types of leak detection methods out there.
In part one, we’re focusing on internally-based leak detection systems, methods that use field instruments to analyze the inside of pipes and plumbing systems.
Hydrostatic test: This is often performed on pressurized pipes before they are made fully functional. It often involves coloured dye being put through the pipe and waiting to see if any coloured water comes out of the pipe where it isn’t supposed to. The pipe is also pressurized to its maximum safe limit to test the strength of the entire system. After these tests have been passed, the pipes are cleared for use. This is a standard test that combines internal and external leak detection methods to some extent.
Pressure/flow monitoring: This is probably the most commonly used method in factory and manufacturing plumbing. The pipes are built with pressure and flow gauges that monitor the internal pipe environment. These gauges are checked regularly and often have built-in alarms that warn people of potential issues.
Balancing methods: Using a series of mathematical formulas based on the conversion of mass. Water entering the pipe is compared with the water leaving the pipe using a series of flowmeters. Any drop in mass is the result of a leak that needs to be fixed. While these tests are accurate, they do not locate the exact location of the leak.
Real-Time Transient Model (RTTM) methods: This is generally considered a step up from balancing methods as it expands on the same basic principles. RTTM uses statistical data using basic physical laws such as conservation of momentum, conservation of energy, and conservation of mass to determine if a leak is present. This method is especially useful because you can determine other factors, like flow, pressure, density, and temperature, in real-time at different points along the pipeline.
Extended Real-Time Transient Model (E-RTTM) methods: Think RTTM but extended over a period of time rather than the immediate present. This method compares current measurements against past statistics to determine leaks, reducing the number of false alarms. E-RTTM is particularly popular for its low false alarm rate and speed since prior data allows for faster computation.
Statistical methods: Using decision theory principles from statistics, a plumbing professional can determine if a pipe is leaking based on relatively limited data. Measurements are made at one end of the pipe and measured against a hypothetical situation that determines if a leak has occurred.
In part two of this two-part series, we will look at externally-based leak detection systems, methods that analyze the external environment of the pipe to see if a plumbing system is leaking.