How the Air Driven Gas Booster Works
The Sprague gas booster is a piston-type, air-operated booster. It uses a mechanically operated, snap-action air selector valve to cycle the booster.
The Sprague boosters, like Sprague air driven hydraulic pumps, employ the piston differential areas principle— a large area air piston, driven at low air pressure to drive a small area compression piston which converts input gas to higher pressure, lower volume output gas.
The booster gas output or discharge pressure developed by the compression piston is determined by the ratio between the area of the air piston, the operating air pressure and the available precharge pressure. The function of the precharge pressure to the booster is to charge the high pressure cylinder inside the booster with gas, reducing the time required to reach higher pressures, and the time to return the compression piston and the air piston for the next compression cycle.
The Sprague booster works rapidly to reach the required pressure, then stops at a pressure balance. The booster will hold the pressure balance indefinitely with minimal energy consumption, heat build-up or parts movement. When a pressure imbalance occurs, the booster will automatically restart to restore the pressure balance.
By using a pressure regulator on the operating air supply line, the outlet gas pressure can be accurately adjusted to any pressure level between the precharge pressure and the maximum discharge pressure.
With some Sprague booster models, the pumping or high pressure section is cooled with exhaust air piped from the air-driving section of the booster. In other boosters, the pumping section employs external fins to dissipate the heat.
Compared to other air-operated gas boosters, the Sprague booster does the same job but with fewer moving parts and seals for less maintenance throughout its service life.
Because of their compact size and low cost, Sprague boosters can be used in high-low combinations to meet higher flow and pressure requirements.
Being air driven and having no electrical connections, Sprague pneumatic boosters are non-sparking. These boosters can be used safely in the presence of flammable or explosive liquids or vapors.
Sprague boosters and other Sprague pneumatic products are designed to a 4 to 1 minimum safety factor.