There exists many industrial facilities that process toxic and/or flammable products and many more will be constructed in the future. If these facilities are not leak tight they are potential safety hazards. Leaking fluids from process facilities pose danger 10 workers, the public, the environment and costly equipment. A method has been developed and employed to test for leaky equipment prior to start-up thereby drastically reducing toxic or flammable hazards while the process is operating. This method may be employed before initial start-up or prior to restart after turn around.
The process involves displacing air from a process facility with an inexpensive tracer gas (1% Helium and 99% Nitrogen) and applying incremental stages of pressure. A combination of thermal conductivity detectors are used to locate and quantify leaks.
The method has proven to detect and record leak rates of less than one standard cubic meter of tracer gas per year. The accuracy of this method far exceeds the capability of methods commonly used by process operators today. As downtime may be costly this method is superior to existing technology because it requires less time to implement and has a reduced cost.
A demand for leak detection technology has led to the development of commercially available methods and equipment. In response to demand for effective but more economical methods and equipment, new advances in Helium storage and silicon chip technology have been exploited. The result is the leak detection technology as described in this paper,
The described leak detection methods and equipment have a reduced cost and are more time efficient than those previously employed. A 12 MMcf/ day gas plant could be leak checked and most of the leaks repaired within one day.
A hand held portable electronic leak detector that employs a thermistor conductivity cell was used to quickly search a facility for tracer gas. A light weight gas chromatograph was used to ensure the accuracy of the hand held unit. The availability of 6000 psig Helium storage bottles has eliminated the necessity of a compressor for continuous addition of Helium to a tracer gas stream,
From the sour natural gas facilities checked with the improved methods and equipment, it was found that a surprisingly large number of new flanged connections leaked tracer gas. By repairing these leaks, start-up of the facilities was conducted in a sale and efficient manner. Exposure to flammable and toxic gases was limited.
This type of leak detection technology has application at any facilities that process toxic and/or flammable fluids:
Natural Gas Plants (Sweet and Sour)
Refineries
Batteries (Crude Oil, Natural Gas and Water Separation)
Compressor Stations (Natural Gas Transmittion Facilities)
Pipeline Heaters
Wellsite Separators and Dehydration Units
Heavy Oil Separators and Upgraders
Any oil field surface handling procedure with associated Natural Gas
Chemical Plants
Leak detection tests within plants that process toxic or flammable products have clear benefits.
