Any thorough examination of current trends in process development should include consideration of the steady move toward higher operating pressures in various fields. Certain reactions which are favored at higher pressures are being investigated not only in the laboratory, but now are being expanded into semiworks and even into full commercial scale. Reactions formerly undertaken only at lower pressures are being developed for use at high pressures because of higher efficiencies and better yields. Equipment manufacturers certainly have felt the impact of this trend in that high-pressure specifications are definitely increasing. Controlled-volume pumps are required for many developments in this high-pressure field and this paper is an examination of their design and application in the range of 10,000 to 30,000 psi.