PURPOSE: To easily carry out pressure and flow compensation control, by replaceably providing a closing member or a restriction member in a passage for communicating a spring chamber with a pressure line in a control valve block, and selectively connecting one end of the spring chamber to a flow adjusting liner or a maximum pressure setting line.

CONSTITUTION: In a passage 29 for connecting a spring chamber 23 with a pressure line 16 in a control valve block 21 mounted to a pump housing 1, there is replaceably provided a closing member for closing the passage or a restriction member 30 for restricting the passage. At one end of the spring chamber, there is provided a plug 34 selectively connected to a flow adjusting line or a maximum pressure setting line 36. Accordingly, it is possible to arbitrarily and selectively carry out pressure and flow compensation control of the pump by arbitrarily replacing the closing member, the restriction member 30 and the plug 34.