Tuthill’s severe-duty process pumps that solve tough pumping problems. For pressures up to 450 psi (31 bar) and viscosities up to 1,000,000 cps. HD Series Lobe Pumps are of the circumferential piston lobe design which maximizes the pump hydraulic efficiency. The pumps are designed to run dry without risk of seizure; with external flushing into the seal cavity.