Having the right information allows us to ensure that our engineers design and configure a pump to best suit your specific requirements. We analyze every detail to ensure that the selected equipment meets your expectations in terms of performance, efficiency and durability, thus providing you with the best solution for your needs.

Simply let us know the following and we will suggest the best pump model for you!

• Fluid name, concentration, specific gravity, viscosity, solids data, temperature, flammability, flammability, etc.
  
• Total dynamic head (TDH) and required flow rate
  
• NPSHa (Net Positive Positive Suction Head Available)
  
• Application Description
  
• Customer experience with suitable materials of construction

These are the basic concepts indicated and the factors that influence the selection of a pump.

Fluid name and concentration

• Fundamental for deciding pump materials of construction
• If the fluid is a trade name, refer to the MSDS (material safety data sheet)
• Chemical resistance may vary with concentration and temperature.

Specific Gravity

• Specific gravity is the weight of a given liquid compared to the weight of an equivalent volume of water.
• By definition, water has a specific gravity of 1.0, but many chemicals have a specific gravity greater than 1.0.
• Many solvents and petroleum distillates have a specific gravity lower than 1.0.

Viscosity

• Viscosity is a measure of a liquid’s resistance to flow.
• Required to calculate friction loss in the piping system.
• Required to correct the pump curve.
• Common units are cP (centipoise) and cSt (centistoke).

Flammable Liquids

• Great care must be taken when applying a pump for flammable fluids.
• Use only stainless steel pumps, DB Series with PVDF construction, or UC Series.
• Use only explosion-proof motors.
• Use centrifugal pump with bronze wear ring option where available.
• Ensure all components are grounded and bonded.

Flow

• Flow is the volume of liquid to be pumped.
• It may be expressed in GPM (gallons per minute) or metric units like m³/hr (cubic meters per hour) or lpm (liters per minute).
• Flow is required to calculate friction loss in the user’s piping system.

Pressure

• Often referred to as TDH (Total Dynamic Head)
• It is the discharge height minus or plus the suction height.
• Based on the piping system
• Along with flow, it is necessary to select a pump from the published curves.
• Expressed in feet or meters

Suction Pressure

• Suction pressure exists when the liquid supply is ABOVE the pump.
• Equal to the static height (in feet or meters) above the pump centerline minus suction line losses.
• Commonly known as “flooded suction” applications.

Suction Lift

• Suction lift exists when the liquid supply is BELOW the pump.
• Equal to the static height (in feet or meters) below the pump centerline minus suction line losses.
• Usually requires a self-priming pump such as our SP Series.

Discharge Pressure

• Discharge pressure consists of:
• Static discharge pressure
• Friction loss in discharge piping and fittings
• Pressure in the discharge container (if any)
• Any sudden expansion losses
• Outlet losses

System Pressure

• The system curve is a graph of the head required for liquid to flow through the piping system.
• A centrifugal pump always operates at the intersection of the head-capacity curve and the system curve.
• The system curve includes: Static head, Pressure head, Friction loss in piping and fittings.

Net Positive Suction Head (NPSH)

• NPSH is the suction head required by the pump and provided by the piping system to avoid cavitation.
• Called “net” because vapor pressure is always subtracted, thus it is above or “net” of vapor pressure.
• Called “positive” because values are expressed in absolute pressure—either absolute feet or meters.

Cavitation

• Occurs when NPSHa is less than the NPSHr required by the pump.
• Cavitation bubbles form in the low-pressure area and collapse rapidly in higher-pressure zones, causing erosion damage.
• More likely with hot fluids, fluids with high vapor pressure, suction sources under reduced pressure (vacuum), or large impellers operating near full flow.

Temperature

• Maximum ambient temperature: usually based on motor’s max temperature rating.
• Minimum ambient temperature: usually based on pump construction materials.

Altitude

• Higher altitudes:
• Reduce suction lift capacity
• Reduce NPSHa
• Affect motor cooling by reducing fan efficiency

Atmosphere

• Hazardous atmospheres: follow guidelines for pumping flammable materials
• Corrosive vapor atmospheres: consider chemical-duty motors
• Washdown areas: consider washdown-duty motors
• High humidity: consider tropical-duty motors