THE PM MANUAL PUMPS ARE SUPPLIED FOR CENTRALIZED LUBRICATION SYSTEMS WITH OIL WHERE RESISTANCE METERING UNITS ARE USED. PRIMING IS CARRIED OUT BY GENTLY UPLIFTING THE HANDLE AND THE SLOW AND AUTOMATIC RETURN ACTUATED BY MEANS OF A SPRING DETERMINES THE DELIVERY TO THE SYSTEM. A QUICK RETURN OF THE HANDLE MEANS THE RESERVOIR IS EMPTY.