Suntec Oil Pump Selection Guide: Matching Flow Rate & Pressure to Your Burner
- Identify the shaft rotation direction (L for counter-clockwise, R for clockwise) before purchasing a Suntec replacement pump.
- Check nozzle line exits (Left or Right) to prevent piping issues during installation on standard burner flanges.
- AS and AL series feature built-in solenoid cutoff valves to block oil drip, whereas AN models require external solenoids.
- Operating diesel burner pumps at 12 bar optimizes atomization while keeping electric motor workloads in safety tolerances.
Suntec pumps draw fuel from storage and deliver it to the nozzle. Key selection criteria: pump model (AS/AL has built-in cut-off; AN/AD does not), flow capacity (l/h), rotation direction (clockwise/counter-clockwise looking at shaft), and hub diameter (32mm or 54mm). Set pressure between 10-15 bar for diesel combustion.
If your diesel burner or LDO furnace is sputtering, failing to build pressure, or leaking oil from the shaft seal, your fuel pump likely needs attention or replacement. Suntec is the world's leading manufacturer of fuel pumps for residential and industrial burners.
However, choosing a replacement Suntec pump can be confusing due to the complex model numbers stamped on their bodies (e.g., AS 47 C 1537 6P 0500). Installing the wrong pump can run the motor backwards, cause seal failure, or starve the burner.
Here is a practical engineer's guide to deciphering Suntec pumps.
1. Pump Series Features (AS, AL, AN, AP, E, TA) Suntec designates their pump capabilities by the first letters: - AS Series (e.g., AS 47, AS 57): The most common pump for small burners. It has a built-in solenoid valve that performs a quick cut-off, stopping oil flow immediately when the burner shuts down to prevent oil dripping onto the combustion chamber floor. - AL Series (e.g., AL 35): Similar to AS, but the built-in solenoid is designed for blocking rather than inline bypass. Used when secondary controls manage cut-off. - AN Series (e.g., AN 57, AN 67): Basic pump without a built-in solenoid valve. Oil pressure cut-off is handled by an external inline solenoid valve. - E Series (e.g., E 1069): Designed for medium/heavy fuel oil and higher pressure demands. - TA / T Series: Heavy-duty industrial pumps for large plants.
2. Decode the Rotation and Nozzle Outlet This is where 80% of incorrect orders occur. You must determine the shaft rotation and nozzle exit relative to the shaft. - Hold the pump with the shaft pointing directly at you: - Clockwise (R): Shaft rotates clockwise. - Counter-Clockwise (L): Shaft rotates counter-clockwise. - Look at where the nozzle port (copper tube connection) is located: - Right hand (R): Nozzle outlet on the right. - Left hand (L): Nozzle outlet on the left.
The model number encodes this: e.g., "AS 47 C..." indicates counter-clockwise rotation and left-hand nozzle outlet. "AS 47 A..." indicates clockwise rotation and right-hand nozzle outlet. Operating a pump in the wrong rotation will damage the gear set and build zero pressure.
3. Flow Rate and Pressure Adjustments Ensure the pump gear capacity (e.g., 47, 57, 67, 77) matches your nozzle size: - AS 47: Delivers ~46 liters per hour at 12 bar pressure. Ideal for burners up to 450 kW. - AS 57: Delivers ~55 liters per hour. - AN 67: Delivers ~67 liters per hour, suitable for larger industrial heating units.
Standard diesel burners require oil pressure set between 10 to 15 bar (factory set at 12 bar). Adjusting the pressure regulator screw clockwise increases pressure, which atomizes the fuel finer but increases motor load. Never exceed the pump's rated maximum pressure (typically 15-25 bar depending on series).
Burner Spare Part Comparison Table
| Parameter | Suntec AS47 | Suntec AL35 | Suntec AN67 |
|---|---|---|---|
| Solenoid Cut-off | Built-in (Inline) | Built-in (Blocking) | None (Requires external) |
| Flow Rate (at 12 bar) | 46 Liters/Hour | 35 Liters/Hour | 67 Liters/Hour |
| Typical Heat Duty | Up to 450 kW | Up to 350 kW | Up to 650 kW |
| Viscosity Range | 2 to 12 mm²/s | 2 to 12 mm²/s | 2 to 75 mm²/s (heavy oil OK) |
"We operate a namkeen frying factory in Ahmedabad. Our diesel burner pump kept losing pressure, leaving us with half-cooked batches. Sukhdev Raval's team at Gajanand Engineering & Services supplied a genuine Suntec AS47 pump with the exact rotation specs. It was installed in under an hour, and fuel pressure has been steady ever since."— Rajesh Patel, Owner, Patel Snacks Food Processing, Ahmedabad
Frequently Asked Questions
Why is my Suntec pump making a high-pitched whining noise?
A whining noise usually indicates air entering the suction line (vacuum leak) or a clogged suction filter inside the pump body. Clean the internal mesh filter and verify fuel line joints.
Can Suntec pumps run on heavy oil (LDO/Furnace Oil)?
Standard AS/AL pumps are rated for light oil (diesel). For heavy LDO or furnace oil, you must use specialized pumps like the Suntec E, J, or TA series which handle higher viscosities and have internal heaters.
Where is the official dealer for a genuine Suntec oil pump in Gujarat?
You can buy the authentic Suntec oil pump directly from the stockiest showroom of Gajanand Engineering & Services in Odhav, Ahmedabad.
How do I determine the rotation direction of a Suntec oil pump?
Read the model codes or consult the technical engineers at Gajanand Engineering & Services to choose the correct rotation layout for your Suntec oil pump.
Can I claim GST credit when buying a Suntec oil pump?
Yes, Gajanand Engineering & Services provides valid tax invoices for every Suntec oil pump purchase so your business can claim full Input Tax Credit.
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Sukhdev founded Gajanand Engineering & Services in 2012 and has over 12 years of hands-on technical expertise calibrating, servicing, and supplying industrial combustion systems and original boiler spares across Gujarat and India.
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