Complete Guide: Parts, Working, Types, Tips to Keep in Mind & More
The most crucial factor in ensuring that your pump system runs for years without causing frequent problems is to – get the installation right. You may have chosen a high-quality pump, but without the right installation procedure, your pump is likely to face numerous operational challenges.
In this guide from Sintech, leading industrial pump manufacturer in India, we give you all that you need to know about centrifugal pump installation – the steps involved, points to keep in mind, and more.
What is a centrifugal pump?
Centrifugal pumps are the most commonly used pumps for transferring fluids from a low level to a higher level. Here’s the definition of centrifugal pumps:
"A centrifugal pump uses rotating impellers to impart velocity to a liquid. It then converts the generated velocity into a flow."
It's a hydraulic machine that converts mechanical energy into hydraulic energy by generating centrifugal force that acts on the fluid. The rotating impeller in a centrifugal pump moves the fluid (water or other liquids) using centrifugal force.
Centrifugal pumps are used in various industries, like – food processing, mining, petroleum, pharmaceutical, chemical, and several others. It can handle large volumes of liquids and generate high flow rates. They are mostly used for transferring fluids with low viscosity like – water or light-weight oils. Liquids with a higher viscosity require higher horsepower. Hence positive displacement pumps are better suited for highly viscous liquids.
Main Parts of a Centrifugal Pump
1. The Impeller
It's a rotor or wheel with an array of backward curved blades (known as vanes). The impeller is mounted on a shaft that is coupled to an external energy source. The external energy source rotates the impeller during pump operation. Impellers can further be classified into three types: open, semi-closed, and enclosed.
Open; Semi-closed; Enclosed
The casing is a pipe whose upper end is connected to the impeller's eye (centre). The lower end of the casing dips into the displaced fluid, causing it to lift the liquid. Generally, the lower end of the casing has a foot valve and strainer.
Casings in centrifugal pumps can be divided into volute casing, vortex casing, and a casing with guide blades.
3. Delivery Pipe
The lower end of the delivery pipe is connected to the pump outlet. The role of the delivery pipe is to transport the fluid to the required height. It is fitted with a valve that controls liquid flow from the pump.
4. Suction Pipe
One end of the suction pipe is connected to the impeller's inlet, and the other end dips into the water sump. At the end, where the suction pipe touches the fluid, it is fitted with a filter and foot valve. The foot valve moves only in one direction – i.e., upward — the strainer filters out dirt, residue, and other waste particles present in the water.
Working of a Centrifugal Pump
The first step is priming. Priming is essential as the pressure generated in the impeller is directly proportional to the density of the fluid, it comes in contact with. Priming is ensuring that all air from the inside of the pump is driven out.
Once the pump is primed, the next step is to ensure that the delivery valve is kept closed. Next, the electric motor (the external energy source) is started, which in turn, begins the rotation of the impeller.
This causes the liquid to flow in an outward direction radially, passing the vanes of the impeller. This generates a centrifugal vacuum in the pump. This causes the fluid to flow from the sump via the suction pipe to the impeller's eye, causing the liquid to be lifted to the desired height via the delivery pipe.
Types of Centrifugal Pumps
Centrifugal pumps are classified into different types based on various features. They are:
|Number of Impellers||· Single-stage Pump|
· Two-stage Pump
· Multi-stage Pump
|Orientation of Case-Split||·Axial Split|
· Radial Split
|Impeller Design||· Single Suction Pump|
· Double Suction Pump
|Industry Standards||· ANSI (American National Standards Institute)|
· DIN Pump
· API (American Petroleum Institute)
· ASME (American Society of Mechanical Engineers)
· ISO Pump
|Shaft Orientation||· Horizontal Pump|
· Vertical Pump
|Bearing Support||· Overhung|
|Volute Number||· Single Volute|
· Double Volute
Installation of Centrifugal Pumps – Steps Involved
Here is a step-by-step guide for the installation of centrifugal pumps:
Step 1: Understand the Manufacturer’s Installation Instructions
All centrifugal pumps come with an Operation & Maintenance Manual. Make sure to thoroughly read the manual before you begin the installation process. Besides giving information on pump maintenance and operation, the manual also has a detailed guide on installing the pump.
Ensure that you understand the instructions before installing the pump. Remember that failing to comply with the manufacturer's instructions can lead to the voiding of the warranty.
Step 2: Visually Inspect the Pump for any Signs of Troubles
The next step is to do a thorough visual inspection of the pump. You can ask the pump manufacturer if they have an inspection checklist. If yes, follow the list. If no, you can ask the manufacturer to guide you on the items you must inspect before attempting installation.
Here are a few items to inspect:
Check if all equipment is proper – no leaking seals, guards are in place, electrical connections are properly terminated, etc.
Next, check for the alignment of the pump using a machinist level.
Check lubricant levels and verify if the seal if correctly assembled.
These are just the essential inspection checklist. You are sure to have more. The critical point here is to be thorough and detailed.
Step 3: Installation
You can either bring in a manufacturer-authorized technician to do the installation or go with your in-house technicians. Besides the installation, the technician will carry out other services like – alignment inspection, vibration measurement, flatness measurement, etc.
Make sure that the technician you hire is qualified to carry out the installation in the proper way.
Things to Keep an Eye on during Centrifugal Pump Installation
Even if you hire a third-party technician to handle the installation, you need to keep an eye on certain things. Here’s what to look for during the installation process:
Industrial centrifugal pumps are large and heavy. Hence they need a robust foundation. Ensure that the foundation on which the centrifugal pump is mounted on is hard enough to support the rest of the unit.
The bolts used in the foundation must be of the right size and embedded well into the concrete. Use a pipe sleeve that is larger than the bolt.
The base of the pump must be levelled so that the pump shaft is vertically aligned. The suction pump must be mounted vertically, while the discharge flanges are mounted horizontally.
Ensure that there is enough spacing between the coupling halves' faces so that they do not strike against each other. The coupling halves are likely to hit each other when the driver rotor is moved facing the pump. Make sure that the technician uses a taper gauge and straight edge to check for the alignment.
Ensure that discharge and suction pipes are supported independently using support blocks and pipe hangers. This prevents excessive strain on the casing and joints of the pump system. The alignment of the pipe must be checked before a connection is created. Ensure that the piping follows industry standards. Irregular assembly of the piping system will lead to excessive power consumption and a drop in pump efficiency.
The wiring used in the pump system must be of adequate size to prevent voltage drops. Ensure that the pump is not started prematurely until it is filled with the fluid.
The orientation of the rotation of the centrifugal pump is mentioned in the casing. Ensure that the pump is fixed in the correct rotation direction, before assembling the coupling on the base.
Connect the earth wire to the ground and then connect the other end to the terminal.
The pump's suction line should be filled slowly with the fluid until a steady flow is generated. Ensure that you open the air vent to eradicate all air from the casing.
Starting the Pump
To start your pump, the gate valve in the discharge line should be closed. As the motor approaches full speed, the discharge line should be opened gradually.
Periodic servicing of the pump is essential to keep it in good condition and without any problems.
What are the steps involved in the operation of a centrifugal pump?
Let’s now take a look at the various steps involved in the operation of the pump:
Open the suction valve – This causes the liquid to flow into the impeller and fill it up.
Open the vent valve – The vent valve is on the discharge line. This drives out air from the casing, which is now filled with liquid.
If you notice any liquid seeping out of the vent valve, you can close it.
Open the bypass valve in the discharge valve.
Start the pump and let it run until capacity. Check the pressure gauge on the discharge line to see if it has attained capacity.
Once the pressure gauge becomes stable, open the discharge valve.
A Final Word of Advice
We highly encourage you to follow the manufacturer's instructions at every step. The manufacturer is responsible for designing and producing the pump equipment. Hence, they are more aware of the system's capabilities and sensitivities and handle the warranty clause against defects. You must keep the warranty intact so you can make claims against any manufacturing defects if present.
Once you have followed the right installation steps, you can breathe easy knowing that your centrifugal pump is ready for operation and will run for years to come.
Sintech Pump is one of the top centrifugal pump manufacturers in India. We offer a wide array of industrial pumps for all industries. Get in touch with our team to find the right pump for your needs.