Technical

There are several reasons as to why the permitted full load current could be exceeded when operating the pump: undervoltage, current imbalance in three-phase motors, motor has a short circuit, incorrect wiring or faulty electrical connections, viscosity or density of the pumped medium too high, or the pump is worn or blocked. However, the pump may also be undersized for the application in question, and may be operating in excess of its nominal flow rate. In this case, try to partially close the shut-off valve on the pressure side in order to throttle the flow rate until the motor current returns to the acceptable limits.

In order to increase the service life of both pump and motor, always use control panel. By using Control panel, the submersible pump is saved from various conditions like undervoltage, current imbalance, single phasing, short circuit or faulty electrical connections & many more. Control Panel also safeguard pump when the motor is overload due to viscosity or density of the pumped medium too high, or the pump is worn or blocked.

The pump’s input power is the pump’s power requirement under the present operating conditions. The rated motor output, including the operating factor, must be equal to or greater than the pump’s power requirement. If the pump’s power requirement is greater than the rated output of the motor, the motor is drawing more current than intended. This leads to overheating of the motor, and will potentially damage it. The performance curve have pump related data like its flow, head, outlet size, solid handlig, efficiency etc,.

The term “inlet” refers to a suction state with positive inlet pressure in which the pumped medium is supplied from a point located above the pump’s suction port and which is in contact with the atmosphere (open system). This means that the pressure applied at the pump’s suction port is greater than or equal to atmospheric pressure.

No, most pumps which are designated as self-priming have a lift potential of 20-25FT vertical or its equivalent. It is a matter of atmospheric pressure (14.7psi at sea level) pushing on the surface of the water and therefore into the pump. The suction lift potential is controlled by Mother Nature, not the pump motor size.

No, bigger is better. Since all hose/pipe has friction loss (resistance to flow) based on liquid velocity and hose/pipe size, bigger is better. Just like electricity in a wire. There are common, published friction loss charts for various hose/pipe sizes. Often the friction loss factor is provided at a given flow (gpm) per 100FT of pipe length. Since the loss is exponential, the more you try to push through the pipe the significantly higher this loss becomes.

No, the Max values provided are both at opposite ends of the pump performance curve. They are simply a guide for someone familiar with pumps to quickly assess the suitability of a pump size for an application. The Max Head / Pressure is at zero (0) flow and Max Flow rate is at zero (0) head or very close to it. You need to look at the pumps performance chart or curve and look at a particular flow rate and pressure you need.

Slurry Pumps

Slurry Pumps are a heavy and robust version of a centrifugal pump, capable of handling tough and abrasive duties. The term Slurry Pump, as stated, covers various types of heavy duty centrifugal pumps used for hydraulic transportation of solids.

Slurry Pumps are used for a variety of applications such as highly abrasive slurries, mill scale, iron ore & pallet slurries, Mineral Ore processing units, Ash & Coal Handling Plants, Granite & Marble Slurry, Jack well & intake well cleaning, Removal of sand deposition at dam galleries & penstock tunnels & many more similar applications.

Solid particles in the pumped medium generate friction, which leads to abrasion of the material. This is a frequently occurring problem in sewerage technology caused by sand in the pumped medium, which destroys pump components like impellers, casing etc.,.

Your submersible pump may not be giving proper discharge owing to various reasons. Please check the manufacturers troubleshooting guide, consult a trained mechanic or a customer service representative. The troubleshooting guide is available in Manual provided with the pump.

Dewatering Pumps

A submersible dewatering pump is one that is used for pumping out water/fluid from waste water tanks, rain water pits, mining pits, or from similar sources. These pumps allow suspended solid particles to pass though the impeller vanes. However, the particle sizes that the pump can handle will depend on the design of the vanes. These pumps are generally open or semi-open impeller. The prime mover is a sealed electric motor. A submersible cutter pump is a variation of the dewatering pump, which allows solid particles to pass through the impeller after being shred through a cutter.

Dewatering Pumps are used for a variety of applications such as Basement & Storm Water Dewatering, Pumping Heavily contaminated water with sand gravel and sludge at various construction sites, Sea water pumping, Industrial water dewatering, Micro tunneling projects, underground civil projects, Flood Relief Pumping, Mines Dewatering & many more similar applications.

Due to the modern design and manufacturing process, the motors currently in use often become hotter during operation than motors used in the past. In practice, the surface temperatures of some modern motors may reach temperatures of up to 90°C (194°F). Nevertheless, the service life of such motors is equal to or even greater than that of the old motors. High surface temperatures are not necessarily a sign that something is wrong. However, if the motor becomes excessively hot during operation, a number of causes may be at work:
i. Electrical causes: Under voltage or overvoltage, asymmetrical three-phase current, diminishing insulation resistance.
ii. Environmental impacts: High ambient temperatures, lack of ventilation or poor ventilation, high installation elevation (low air density).
iii. Mechanical causes: Too many switching cycles, flow rate too high or too low, high resistance to rotation due to damaged pump, high viscosity or density of the pumped medium, clogged or blocked pump.

If the pump is operating too far to the left on the curve, this simply means that the pump is delivering high pressure but at a flow rate that is low or non-existent. High pressure inside the pump stresses the impeller unit and thus increases pressure on the motor bearings. In the extreme case, this will cause damage to the pump and motor. If the flow rate is below the minimum flow rate required for the pump, the pumped medium may also overheat and damage the pump. For this reason, the pump must always be operated inside the lower and upper flow rate bounds. Ideally, the pump should be operated as close as possible to the point of optimal efficiency in order to ensure a long service life and in order to minimize energy consumption.

When a pump operates too far to the right on the curve, this simply means that the pump is delivering a flow rate greater than that for which it was designed. In other words: The pump is too small for the volume flow needed by the system. Operating the pump in this range may cause damage to the pump and the motor. The pump must always be operated within the lower and upper flow rate bounds. Ideally, the pump should be operated as close as possible to the point of optimal efficiency in order to ensure a long service life and in order to minimize energy consumption.

Non Clog and Waste Water Pumps

Non-clog submersible pumps are ones which have an open or semi-open impeller that allows clogs, rags or suspended particles to be pumped along with the fluid. A cutter is required before the impeller vane to shred the clogs, rags or other suspended particles.

Non-clog Pumps are used for a variety of applications such as Raw & unscreened Sewage, Industrial wastes & effluents, Municipal Sewer Lines, Tailing ponds, Sewage treatment plants, Effluent Treatment Plants, Pharmaceutical & textile units & many more similar applications.

Your submersible pump may not be working owing to various reasons. Please check the manufacturers troubleshooting guide, consult a trained mechanic or a customer service representative. The troubleshooting guide is available in Operation & Maintenance Manual.

The minimum level of submergence for a submersible pump depends on the type of service and the load the motor is subjected to. For continuous service, the pump must be completely submerged in the pumped fluid; for intermittent service, the pump also works when partially submerged (up to its minimum submergence level) but it must be allowed to rest for reasonable periods to prevent the motor from overheating.
Some of our models are fitted with a special cooling casing so they can operate continuously even when partially immersed.

During operation, a pump motor can face overload. Knowing the most frequent causes of overload can help prevent malfunctions. The main reasons for overload can be: the impeller is blocked by foreign particles, the mechanical parts block due to excessive stopping times, the density of the liquid is greater than the maximum permitted density etc.. If you have any doubts, contact your dealer or specialized Darling Pump maintenance technician.

Clear and Raw Water Pumps

A submersible Clear water pump is one that is used for pumping out or transfer water/fluid from one tank to another tank or from other similar sources. These pumps only allow clear water to be transfer with no solid particles because these pumps are generally designed to handle clear water applications. The prime mover is a sealed electric motor. Other submersible pumps are different, they allows solid particles to pass through the impeller.

Submersible Clear Water Pumps are used for a variety of applications such as – Pumping water from UG tank to OH Tank in housing & commercial complex, Hotels, Hospitals etc., Fountains, Waterfalls, Landscaping, Agriculture/irrigation projects, village & Municipal Water Supply, River Water Pumping, Fire Fighting & many more similar applications.

Your submersible pump may not be working owing to various reasons. Please check the manufacturers troubleshooting guide, consult a trained mechanic or a customer service representative. The troubleshooting guide is available in Operation & Maintenance Manual.

Stainless Steel Pumps

Hot Water Pumps