A microprocessor controlled timer is installed in a petroleum service station product dispensing system that includes a pump relay, a pump, a dispenser, and a leak detection monitor. The timer activates pump relays to pressurize a liquid product line that runs from a tank to the dispenser at predetermined...http://www.google.com/patents/US5375454?utm_source=gb-gplus-sharePatent US5375454 - Programmable pump controller
