Double-diaphragm pumps

FIGURE 7.11 Schematic of double-diaphragm pump controls. 

Nutrients were measured in a Technicon AA-II Autoanalyzer every 2 min on a continuous flow of seawater pumped to the instrument. A 2.54-cm inside diameter (ID) nylon hose with the intake at 2.5 m was led on board to a deck-mounted, air-operated double diaphragm pump (Wilden Pump and Engineering Company, Model M-4, Colton, CA). A debubbler... 

There are trade-offs for magnetic drive and canned pumps versus centrifugal pumps with double-mechanical seals. The former have no seals to leak, but need active interlocks to prevent high temperature for temperature sensitive materials. Similarly, diaphragm pumps, that have... 

The double-diaphragm suction-lift pump LNAPL recovery system is patterned after the concept of a shallow well-point dewatering system commonly used in the con-... 

Components of the pumping system reflect both practical aspects related to the characteristics of the site facilities and the subsurface hydrogeologic conditions encountered. The pumps selected are pneumatic, double-diaphragm suction-lift pumps. The advantages of these pumps include ... 

Near-shore facilities are typically characterized by shallow groundwater conditions. The occurrence of LNAPL product on the water table presents the need for immediate containment and continued recovery of the product to abate degradation of ground-water quality, hydrocarbon vapor migration, and discharge of hydrocarbon product to surface waters. A pneumatically operated, double-diaphragm, suction-lift pump has been frequently used in such circumstances to contain and recover LNAPL. 

Double-diaphragm suction-lift pumps also have advantages relative to varying subsurface hydrogeologic characteristics encountered at different sites. These include ... 

Because of the undesirability of using gland packing, reciprocating pumps are not suitable for pumping solvents and, if a positive pump is needed, double-diaphragm air-operated pumps are worth considering. 

Adhesive used in dip applications shonld be kept under continuous agitation. If a dip tank is used, double diaphragm type circulating pumps are recommended and impeller type agitators shonld be nsed. 

FIGURE 9-10 Concept of double acting piston duplex diaphragm pump. (Courtesy of Wirth Pumps.)... 

The heart is located in the center of the thoracic cavity. It sits directly above the muscles of the diaphragm, which separates the thorax from the abdomen, and lies beneath the sternum between the two lungs. The heart is enclosed and anchored in place by a double-walled fibrous sac referred to as the pericardium. The membranes of the pericardium produce a small amount of pericardial fluid that minimizes friction produced by the movement of the heart when it beats. To function mechanically as a pump, the heart must have ... 

---