Pedrollo NGA Open-Impeller Centrifugal Pump for Dirty Water

Open-impeller centrifugal pumps for dirty water with solids up to 20 mm

The Pedrollo NGA is a cast-iron close-coupled centrifugal pump with an open impeller, designed for liquids that are not entirely clean. Because the impeller vanes are open, the pump can pass solid particles in suspension without clogging: Pedrollo gives a maximum passing solid of 12 mm for the NGA 1 and NGA 2 frames and 20 mm for the NGA 3. The datasheet names transfers from channels, rivers, tanks and basins as typical applications, and lists domestic, agricultural and industrial use.

Performance on the 50 Hz datasheet is up to 900 l/min (54 m3/h) at up to 20.5 m head, with motors from 0.55 to 2.2 kW in single-phase (NGAm) and three-phase (NGA) versions. It is therefore a transfer and drainage pump for large volumes at low head, not a pressure-boosting pump.

Technical specifications

Models and duty points

The head figures are the first point of the published table. At the same motor rating the NGA 1 reaches roughly twice the head of the NGA 2. Datasheet absorbed current ranges from 3.8 A for the NGA 1B three-phase pump at 230 V up to 8.3 A for the NGA 3A.

Selection and installation notes

Choose the NGA when the liquid carries sand, leaves or small solids that would block a closed-impeller pump, and accept that an open impeller is less efficient than a closed one on clean water. It is not a slurry or sewage pump: the datasheet describes liquids that will not damage the pump components, so abrasive, fibrous or chemically aggressive liquids need a different design. Keep suction lift within 7 m, fit a strainer to stop oversized debris, and run the pump primed at all times because the mechanical seal depends on the liquid for lubrication. Pedrollo lists stainless steel ISO 228/1 flanges for suction and delivery, NPT ports, 60 Hz and other voltages as options.

For heavy abrasive slurry duty see the Warman AH slurry pump, and for submersible dirty-water pumping browse the pumps category.

How the Pedrollo NGA works

The motor turns an open impeller inside the pump body. The impeller throws the liquid outward, and the liquid leaves through the delivery port. Because the vanes are open, solid particles in suspension pass through the pump without blocking it.

Where the NGA is used

• Transfer from channels and rivers
• Tank and basin emptying
• Drainage of dirty water
• Agricultural water transfer
• Industrial liquid transfer

Selection checklist for the NGA

• Flow rate
• Head
• Size of solid particles
• Single or three-phase supply
• Motor power
• Suction lift
• Liquid temperature
• Port size

Installation, commissioning and maintenance notes for the NGA

Install the pump as close as possible to the liquid and keep the suction line short and tight. Fill the pump body with liquid before starting. Check the direction of rotation on a three-phase motor. Do not run the pump dry. Inspect the mechanical seal and the impeller at regular intervals.

Requesting a quotation for the Pedrollo NGA

Please send the flow, the head, the liquid and the electrical supply. Seven Star LLC serves industrial customers in Oman and the GCC and replies with a quotation based on the information provided.

NGA pump type

It is a close-coupled centrifugal pump.

NGA impeller

It has an open impeller made of cast iron.

NGA dirty water duty

It is designed for liquids that are not entirely clean.

NGA passing solids

The maximum passing solid is 12 mm for the NGA 1 and NGA 2 frames.

NGA 3 passing solids

The maximum passing solid is 20 mm for the NGA 3 frame.

NGA applications

The datasheet names domestic, agricultural and industrial use.

NGA maximum flow

The flow is up to 900 litres per minute, or 54 cubic metres per hour.

NGA maximum head

The head is up to 20.5 m.

NGA duty profile

It is a transfer and drainage pump for large volumes at low head, not a pressure-boosting pump.

NGA motor power

Motor power runs from 0.55 to 2.2 kW.

NGA single-phase version

The single-phase version is called the NGAm.

NGA three-phase version

The three-phase version is called the NGA.

NGA suction head

The manometric suction head is up to 7 m.

NGA liquid temperature

The liquid temperature range is minus 10 to plus 90 degrees C.

NGA ambient temperature

The ambient range is minus 10 to plus 40 degrees C.

NGA working pressure

The maximum working pressure is 6 bar for the NGA 1 and NGA 2 and 10 bar for the NGA 3.

NGA pump body

The pump body is cast iron with a cataphoresis treatment.

NGA cover

The cover is stainless steel on the NGA 1 and NGA 2 and cast iron on the NGA 3.

NGA mechanical seal

The mechanical seal uses ceramic, graphite and NBR parts.

NGA motor shaft

The motor shaft is made of stainless steel.

NGA port size

The threaded ports are 1 1/2 inch on the NGA 1 and NGA 2 and 2 inch on the NGA 3.

NGA 1 model range

The NGA 1B and NGA 1A use 0.55 and 0.75 kW motors.

NGA 3 model range

The NGA 3D and 3C use 1.1 and 1.5 kW motors, and the 3B and 3A use 1.8 and 2.2 kW.

NGA weights

Weights of three-phase models run from 12.6 kg to 25.5 kg.

NGA head values

The datasheet head figures are the first point on each performance curve.

Pump records for the NGA

Record the model, the motor current and the seal inspection date.

Choosing the right NGA frame

Choose the frame from the flow, the head and the size of solids in the liquid.

Documents and quotation

The Pedrollo NGA 50 Hz datasheet (4 pages, EN) lists performance, absorbed current, dimensions and materials is attached to this page and is the manufacturer’s own document, not a Seven Star summary. The manual on the Pedrollo product page covers installation.

Before ordering confirm the maximum solid size and the liquid temperature, the supply voltage and frequency, and whether threaded or flanged ports are wanted. Seven Star LLC, an independent supplier in Muscat, quotes the Pedrollo NGA against your duty point and delivery requirement; send the document tag, flow, head and liquid so the right size can be confirmed before an offer is issued.