Do you ever feel helpless that you don’t know what to do to extend the life of your X-ray tube?
The X-ray tube is arguably the most important part of your X-ray machine. While it enables the production of X-ray beams for inspecting components to identify hidden flaws, its efficiency also ensures the quality of result that you obtain after your inspection. However, a lack of good maintenance practice can cost you a lot in repairs and replacement of X-ray tubes over the life of your X-ray machine.
This guide gives you some quality maintenance practice that if you apply can immediately increase your X-ray tube life and reduce your maintenance cost.
So, if you’re ready, let’s find out together.
① Warm up anode before actual exposure is made.
First off, you need to understand that a lot of heat is generated in the process of using an X-ray tube. Even though X-ray tube materials have high thermal resistance, they are not built to withstand instant high heat energy immediately you put on the X-ray machine. The reason is because the anode might receive a thermal shock without preheating it or if it has not worked for two hours or more and this can damage the tube. Think of it like warming up your engine before loading it. To avoid this thermal shock always warm up the anode before exposing it to the electrons coming from the cathode and this will elongate the X-ray tube life.
② Keep the window of the X-ray tube clean.
Another very important thing to keep in mind to increase the lifespan of your X-ray tube is the cleanliness of the window. The window is the opening which allows the electron emission to pass from the anode disc to the sample under examination.
If there is any dirt deposited around the window this can cause absorption of the radiation and can significantly increase the heat in the X-ray tube. This additional heat can cause the breakdown of the tube very quickly.
③ Minimize filament boost time.
Here is the thing, the longer the filament is energized the hotter it becomes and if go on continuously without intermittent breaks then this activity can wear the filament out in no time. To avoid the quick deterioration of the filament, it is necessary to reduce the filament’s boost time as it will preserve the durability of the filament. It will also prevent unstable operation that is often associated with prolonged filament boost times.
④ Control your filament boost and current.
Power without control often has disastrous consequences. This is usually the case when the filament boost and current applied to a filament are not balanced appropriately. To put it simply, X-ray tubes always fare better when minimum current is applied. A very high current leads to evaporation of the filament’s tungsten material that can be deposited on the glass envelope causing a reduction in lifespan of the X-ray tube.
⑤ Apply the minimum recommended current (mA), voltage (kVp) and exposure time.
Another way to elongate the life of your X-ray tube is to employ the strategy of using minimum required resources. Hence, to increase the lifespan of your X-ray tube it is advised that you always apply the minimum recommended current, exposure time, and voltage suitable for every examination. Also, employing a strategy of longer exposure but lower current combination can also help improve the speed of image reception because the tube stays in better condition, longer.
⑥ Follow tube rating charts and anode heating/ cooling curves.
X-ray tube charts often act as a guide to provide safe working parameters to ensure accurate results and preserve the durability of the X-ray tube. Therefore, operating the X-ray tube above the given ratings in the charts provided by the manufacturer often leads to quick deterioration of the internal components like the focal track.
⑦ Adequate cooling of the tube housing must be ensured to avoid excessive heating of oil.
Due to the high temperature occurring because of the heat generated during the production of X-ray radiation it is necessary to ensure that the cooling system is working effectively. Clearly, a failure in the cooling system at any point during the operation of the X-ray tube can reduce its efficiency and even a breakdown of the X-ray tube entirely.
⑧ Do not run anode unnecessarily because it will shorten the life of bearings.
Though the anode is made of tungsten, a high thermal resistant material, still, running the anode unnecessarily without any active sample examination only gives opportunity for the anode to heat up unnecessarily and it can reduce the lifespan of your X-ray tube.
⑨ Do not allow overheating of the filament by repeated exposures in a short time.
Repeated exposures of the filament within short intervals without allowing for cooling at intervals only increases the heating of the filament beyond tolerable points and it can reduce the lifespan of the X-ray tube.
⑩ Do not exceed anode thermal capacity or dissipation rate of the target.
When you exceed the dissipation rate of the target it creates a heat flow that can get into the bearing structure which is dangerous as it can destroy the bearing structure. Also, the heat released can produce gases that interfere with effective dissipation of X-ray electrons.
⑪ Do not rotate the tube housing rapidly from one position to another.
The sudden rapid rotation of the housing of the X-ray tube only causes tension within the X-ray tube which can result in a crack of the housing and affects the vacuum integrity of the housing as well as causing damage to the rotor.
⑫ Be aware of your motor operation.
The speed of the motor during operation is critical for monitoring the generation of heat within the X-ray tube and high speeds can generate enough heat to damage other parts like the rotor. Putting in place heat reducing mechanisms like a heat exchanger can minimize the effect of this operation.
⑬ Switch off the X-ray tube completely.
When not in use it is good practice that you switch off the X-ray tube completely so that it can cool down and recuperate from the last operation. Not observing this practice endangers the components of the X-ray tubes and can shorten the life of the X-ray tube.
⑭ Limit operation to 80% of maximum single exposure ratings.
Working the X-ray tube at a 100% of its capacity increases the tendency to wear out quickly and put the X-ray tube in a state where it constantly needs maintenance and repair. It is often advisable to operate the X-ray tube at 80% capacity as this can be the safe working capacity and elongate the lifespan of the X-ray tube.
⑮ Avoid damage from improper heating and cooling.
Improper heating and cooling can adversely affect your X-ray tube as this introduces shock to the anode disc which can lead to cracking of the anode leaving it ineffective and needing repairs.
➤ Related Article: Common Causes Of X-Ray Tube Failure
➤ Related Article: X-Ray Machine Maintenance: The Complete Guide
What does all these mean? Elongating the lifespan of your X-ray tube requires you to follow some simple processes and good practices. While these practices are not new, most X-ray machine operators are not aware of these procedures and those that are aware fail to carry it out regularly. However, it will help you reduce maintenance cost and unnecessary stress that most operators and X-ray technical officers go through.
Now that you have this information, what is your next move?