You don't need jockey pump as a jockey pump, you need a practical and reliable means of maintaining fire ring main pressure. Jockey pump is the simplest, cheapest, and the most reliable way to achieve that.
If your chemical plant is qualified for active fire protection, you need to ensure that firewater system is always above a certain (minimum) pressure - and you don't want the main firewater pumps (high flow pumps) to be deployed in such service, because they can suffer damage due to frequent short intermittent flow demands. Smart people had come up with a smaller-size pump that can be used to maintain system pressure, and that is a jockey pump.
As to maintain a minimum line pressure, a small jockey pump can be a cost effective method for the firewater system. One alternative is to connect an elevated tank to the system which can maintain the system at the minimum pressure as required.
