Standard construction is nominally rated for 1,000,000 cycles. In actual service, cycle life exceeding this figure is constantly being experienced. Periodic cleaning and lubrication will help in extending life. Severe operating conditions—a heavy side load on the plunger, for example, may shorten cycle life. Since many factors other than the solenoid construction itself have this effect, the rated life expectancy is valid only for the laboratory conditions under which life tests were run. Special long-life designs are available.