Selecting a Gas Booster
In general, an air or gas charging application requires a specific volume to be brought to a specific pressure within a given amount of time. The adjacent Tables will assist you in selecting the most efficient ratio Sprague Products booster for your application requirements. A typical hose pressure testing application:

1. Hose with one cubic foot volume is to be pressure tested at 500 psig. Pressure level is to be reached in three minutes. Available shop air is 150 psi.
2. Using Table 1, Low Pressure Gas Boosters Performance, page 22, find the required receiver pressure of 500 psi. Compare the figures found in the 500 psi discharge pressure column to the desired time of three minutes. The column figures nearest to three minutes is 2 minutes, 45 seconds with a discharge rate of 4.4 standard cubic feet per minute. So, the 5:1 ratio booster will do this job more efficiently than a 15:1 ratio booster.
   
   
3. Note that the booster driving air pressure and above calculations are based on 100 psi, so the shop air pressure of 150 psi must be reduced to 100 psi driving air to operate the booster. Shop air of 150 psi should still be supplied to the inlet port of the compressing portion of the booster. The higher the precharge inlet pressure, the faster the discharge outlet pressure will be reached.
4. For the above hose test, the S-86-JN-5 booster or S- 486-JN-5 booster power unit could be used
   

How the Sprague Products Boosters Work
The Sprague Products 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 Products booster, like Sprague Product 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 Products 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 Products 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 on the market, the Sprague Products booster does the same job but with fewer moving parts and seals, thus less maintenance is required over its service life.

For more information call 440- 838-7690
or email sprague@sprague.curtisswright.com

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