National Pump has a complete line of close coupled vertical turbine pumps for sump or pressure booster application. Our pumps are working around the world in a variety of applications, including municipal water supply, petroleum, desalinization, snowmaking, cooling towers, and industrial process. Features include:
6” – 30” Hydraulics; Flows to: 25,000 GPM; Heads to: 2,500 feet; up to 2,000 HP
Standard or Thrust Balanced hydraulic designs
Cast Iron, Ductile Iron or Fabricated Steel Discharge Heads
Components available in Cast & Ductile Iron; Silicon, Aluminum, & 304, 316 and Duplex Stainless Steel construction
When Should I consider the use of a submersible turbine pump versus a vertical lineshaft turbine pump?
Guidelines on when to use a SUBMERSIBLE PUMP versus a Vertical Turbine Pump:
When shaft elongation problems occur on a deep Vertical Turbine pump setting.
When wells are not straight.
In open sumps where flooding can be a threat to surface mounted motors.
Where space is at a minimum or where appearance or noise prohibits surface installations.
In an In-Pipe Booster application mounted in a horizontal, vertical or inclined position.
Does National Pump stock Stainless Steel impellers?
Yes, National Pump stocks both 304 & 316 grade stainless steel impellers, up through 15” designs with NO performance corrections.
Does National Pump have NSF 61 certification?
Yes, as of September 20, 2019, National Pump has NSF/ANSI/CAN 61 & NSF/ANSI 372 certification for Vertical and Submersible Turbine Pump assemblies. The deep-set Vertical Turbine Pumps are available in configurations that include either oil-lubricated or fresh water flushed enclosed lineshaft or pre-lubricated open line shaft. The short-set Vertical Turbine Pumps are available in either product lubricated or enclosed linshaft configurations. NPC has certified many optional materials to allow our customers the ability to choose the best materials for their specific application. Whether its standard materials, stainless steel or aluminum bronze, we can meet your needs. Bearings options also include bronze, neoprene, marine or vesconite. Wear rings are available in stainless steel or aluminum bronze. Seal options include mechanical seals in split or single cartridge configurations or expanded PTFE yarn packing. Standard coating is Tnemec N-140 Pota-Pox Plus to provide long-lasting protection of the steel components. The complete pump, from the suction to the discharge, is certified to pump drinking water without imparting chemical contaminants or impurities that can affect our health.
Is National Pump ISO certified?
Yes, all pumps that are required to be built to the ISO9001 certification must be manufactured at National Pump’s ISO 9001 certified plant in Glendale, AZ.
What materials are available from National?
National Pump manufactures pumps in a variety of materials to meet our customer’s preference or needs. Bowls and Impellers are available in Cast or Ductile Iron, Cast Steel, Stainless Steel, a variety of Bronzes or Duplex Stainless Steels. Bearing materials are available in Bronze, Marine rubber, and engineered composites.
What is REED CRITICAL ANALYSIS and why should I ask for it when ordering a pump with a fabricated discharge head?
Every piece of rotating machinery (motor, pump, etc.) has a natural frequency or vibration of operation. As the discharge head of the pump supports the motor, it is the responsibility of the pump manufacturer to design the discharge head to withstand the natural frequencies of the motor through its operating speed range (say 45 – 60 HZ, or 1350 – 1800 rpm). Reed Critical analysis is a calculation that is done that looks at the motor frequency and its effect on the stability of the fabricated head and motor structure. Design adjustments are made to the fabricated head to insure vibration free service. (See story on Tacoma Narrows Bridge failure in 1940)
Can I use a Motor and VFD on a Cast Discharge Head?
When using a cast iron discharge head, National Pump Company can only guarantee vibration free operation at full load speed. A cast iron discharge head may be acceptable for operating at reduced speeds if precautions are made by locking-out the operating speed(s) on the VFD IF vibration is experienced from the natural resonant frequency of the motor and discharge head structure. In some cases, modifications can be made to the discharge head to change the resonate frequency of the structure.
Why do actual test efficiencies differ from catalog efficiencies?
Normally catalog performance and efficiencies are ‘best obtainable’ performance derived from testing using standard materials of construction (i.e. Cast Iron Enameled lined bowls & Bronze impellers) with backfilled and highly polished impellers. Any material change or use of a ‘standard’ polish, may reduce pump performance. The Hydraulic Institute sets performance standards and test tolerances for what a manufacturer can or cannot provide. These standards range from – 9% to +16% deviation on Flow, – 7% to +10% on Head, -7% to 0% on efficiency. When specifying a pump, it is important to define early on what your expectations are so that the manufacturer can meet those expectations. Call a National Pump Representative to learn more about the Hydraulic Institute Test Tolerances.
Do you have any installation suggestions on leveling the Pump?
Yes, this info is available in our IOM Manual located on our web site. The preferred levelness is dead level, however, an acceptable tolerance is 0.002 inch per foot. For deep well applications, the leveling of the discharge head is often installed to fit the well straightness, which may exceed the 0.002 inch per foot guidelines.
What is NPSHR (Net Positive Suction Head Required) mean on the performance curve?
NPSHR is the minimum pressure required at the first impeller of the pump to keep the pump from cavitating (i.e. turning water to water vapor in the pump). This differs from NPSHA (available) which is the absolute pressure at the pump suction. Both values are represented in ‘feet’ of pressure. NPSHA must be a minimum of 3 feet more than NPSHR.