Fluid supply system

A fluid supply system comprising:

• a fluid supply source to supply a fluid;
• a first valve unit provided downstream of the fluid supply source to switch between a first open state to permit flow of the fluid from the fluid supply source and a first closed state to block flow of the fluid, the first valve unit having a pilot valve and a main valve;
• a first line which is provided downstream of the first valve unit and in which the fluid flows;
• a second valve unit provided downstream of the first line to switch between a second open state to permit flow of the fluid from the first line and a second closed state to block flow of the fluid from the first line;
• a second line which is provided downstream of the second valve unit and in which the fluid flows;
• a first pressure detector configured to detect a pressure in the fluid supply source;
• a second pressure detector configured to detect a pressure in the first line;
• a third pressure detector configured to detect a pressure in the second line;
• a controller configured to control the first valve unit and the second valve unit, the second valve unit opening if the pressure in the second line is less than a shutoff pressure even if the second valve unit is set in the second closed state by the controller;
• and
• if the pressure detected by the third pressure detector is less than the shutoff pressure at a timing of starting supply of the fluid from the fluid supply source, the controller
• calculating a pressure equalization time from a timing at which opening of the pilot valve is completed to a timing at which the main valve starts opening, based on the pressures detected by the first pressure detector, the second pressure detector and the third pressure detector,
• setting a valve-open waiting time based on the pressure equalization time, and
• controlling opening of the second valve unit upon elapse of the valve-open waiting time after controlling opening of the first valve unit.