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Types HI 11380 and HI 11400
Stainless steel pressure intensifiers
Method of operation
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On startup the system fills from the low pressure (LP) supply line so that the high pressure (HP) line pressure = the LP pressure. The LP pressure on the left of the piston pushes it to the right against the zero pressure tank fluid. When it reaches the end of its travel, the pilot control valve C reverses. |
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The LP supply fluid can now invade the right hand end of the cylinder where the piston's surface area is larger than at the HP end. The greater force (pressure x area) pushes the piston to the left on its first forward stroke. The increased pressure generated at the HP end closes check valve B and is the first step in building the pressure in the HP service line. |
Subsequent forward and reverse strokes are shown on the right. With valve A open and valve B closed the piston moves forward to inject fluid into the HP service line. For the reverse stroke valve B is open and valve A closed.
The intensifier typically becomes stalled in its forward stroke position with the LP inlet pressure x the ratio = the HP outlet pressure. In this situation there is no consumption of hydraulic fluid with both pistons in a static state with pressure locked between the valves A and B. The device can sit indefinitely in this position . . . but the instant there is a drop in the HP pressure line, the piston moves forward to recover the desired pressure. |
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Subsea version
The above diagrams all show the topside version (HI 11380). The subsea version (HI 11400) operates in the same manner, but with a pilot operated vent valve built into the HP service line after check valve A (shown below as V). This is kept closed by the input supply pressure. If this input pressure ceases for any reason, then the valve becomes open and the high pressure is vented away as shown below right.
 
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