The care of trumpet valves is typically a very easy and straightforward process that involves using a special lubricating oil regularly, and some other occasional maintenance. The oil is the most important part, not only for making sure the valves work properly when being played, but also to avoid other damage to the horn. Cleaning the valves periodically, with professional cleaning at least once a year, can also be a way to extend the life of the valves.
The most important part of caring for trumpet valves is simply to have them oiled properly. Generally, it does not hurt to oil the trumpet valves before each time it is played, even if playing it on a daily basis. It is also quite possible to skip a day or two every now and then for convenience, and to save on the need for more valve oil. If going too long between oil applications, the valves can get sticky, and even become abrasive inside the casing.
In addition to oiling the valves, it may also be necessary to clean them every once in a while with a lint-free cloth. This is especially important if, after oiling the valves, they still tend to stick inside the valve casings. That could be because dust, lint, or some other type of debris has stuck to the surface of the valve. Using a dry cloth is generally all that is needed, but a damp cloth will not hurt the valves. Just remember to oil the valves generously afterward, if using water to clean them.
A more thorough annual cleaning can also help keep trumpet valves in optimum condition by removing lime and copper carbonate. These buildups tend to reduce the valves' performance, and could eventually lead to other problems due to abrasion. This type of cleaning should also take place after a long layoff of a year or more, just to ensure that everything is in the proper working condition.
The valves' bumpers may also need replaced from time to time. These pieces of the instruments are made from felt, or a felt-like product, and are located at the top of the valves. When the valve is depressed, the finger pad hits the bumper. Without the bumpers in place, the valve finger pad could cause irritating noise for the player, and possibly the listener as well.
If these simple steps are maintained, trumpet valves can last well more than a decade. In some cases, once the valves get old, they could possibly be rebuilt if the issues are not too severe. This requires a professional, and the instrument should be taken to a trusted repair facility.