Samson 347120 Pumpmaster4 5:1 Stub Pump Bung

The Samson 347120 Pumpmaster4 is a double-acting, air-operated stub pump rated at a 5:1 pneumatic-to-fluid pressure ratio, designed for continuous-duty lubricant dispensing from standard 55-gallon drums and tanks. "Double-acting" is the operationally significant specification here: unlike single-acting pumps that deliver fluid only on the downstroke, the 347120 pumps on both strokes, nearly doubling throughput efficiency at equivalent air consumption — a material advantage in high-volume maintenance operations running multiple dispensing points simultaneously. The height-adjustable 2" NPTM bung adaptor threads directly into standard drum openings, and the adjustable tube depth ensures the pump reaches the drum floor, minimizing residual fluid waste at end-of-drum.

The 347120 is specified for synthetic and mineral-based oil, gear lube, hydraulic oil, and transmission fluid — covering the majority of petroleum-based lubricants used in industrial maintenance, fleet service, and manufacturing environments. The built-in port for the optional pressure relief valve (Part No. 609 007) is a detail worth noting for installations with sensitive downstream dispensing equipment: it allows in-line pressure protection without rerouting the fluid circuit. At 7.257 kg, this is not a lightweight portable unit — it is designed for semi-permanent drum station deployment where the pump remains mounted and the drum is swapped beneath it. For facilities managing multiple lubricant types, the 347120 represents a durable, specification-compliant dispensing solution where air supply is already available at the point of use.