Circulation pump – a pump designed to circulate the heat carrier in a heating system. It is an integral part of any heating system, especially in private houses where a boiler using gas or solid fuel is used.
The main components of this equipment are:
- pump housing;
- rotor;
- stator;
- impeller;
- bearings;
- seals;
- housing cover.
How to choose a circulation pump yourself
If you are wondering how to choose a circulation pump for your heating or water supply system, it is recommended to consider the following criteria:
- Choose equipment with performance that matches the needs of your system. It is determined by its power and speed;
- The pump should be made of high-quality materials resistant to corrosion and having a long service life;
- Make sure the size matches your piping system. It is also necessary to consider that the equipment should be compatible with other components of your system;
- It is best to choose a model with minimal power consumption to reduce your electricity costs;
- If it is installed in a residential area, it is recommended to choose pumps with minimal noise levels;
- A circulation pump with speed control function can save electricity and extend the pump’s service life;
- Choose pumps from reliable manufacturers with product warranties.
How to distinguish a circulation pump from other pumps
Circulation pumps can be distinguished from other pumps by certain criteria. They are compact and smaller compared to other pumps. Their housing is round or square in shape, with protruding connectors for pipe connections.
What a circulation pump looks like from the front
Circulation pumps are designed to circulate water in heating and water supply systems. Usually, the purpose of the pump is indicated on its housing.
The equipment has a certain flow rate and head, which allows it to efficiently circulate water in systems. The technical characteristics of the pump should indicate its maximum flow rate and head.
Models can be connected to systems in various ways, for example, using threaded connections or flanges.
The housing of such equipment can be made of various materials, such as cast iron, bronze, stainless steel, etc. The material of the pump housing should correspond to the operating conditions of the pump.
Some circulation pumps have high energy efficiency, which reduces electricity costs. It is important to pay attention to the energy efficiency class.
Marking of circulation pumps
The labeling of a circulation pump may vary depending on the manufacturer, but usually includes the following information:
- model;
- voltage. For example, 220 V;
- frequency. For example, 50 Hz;
- power. For example, 100 W;
- performance. Indicates the volume of water that the pump can transfer per unit of time, for example, 10 l/min;
- maximum lift height. Indicates the maximum height to which the pump can lift water;
- type of connection. For example, with threaded connections;
- pump type;
- drive type. For example, electric;
- additional characteristics. Include parameters such as the material of the pump housing, rotor type, and others.
Types of Circulation Pumps
Circulation pumps can be of various types, but the main difference lies in the rotor design: wet or dry.
A wet rotor pump is where the rotor is inside the housing, and the fluid it pumps serves as lubrication for the bearings.
A dry rotor, on the other hand, is a model where the rotor is outside the pump housing, and the fluid it pumps is not used as lubrication. Let’s briefly mention the pros and cons of each type.
Wet Rotor Pumps
Pros:
- High efficiency;
- More reliable.
Cons:
- May require more energy to start;
- Requires more careful maintenance.
Dry rotor pumps have the following pros and cons:
Pros:
- More economical;
- Easier to maintain;
Cons:
- Less reliable;
- Lower efficiency.
Methods for selecting circulation pumps
There are several methods for selecting these devices:
- Calculation method: based on calculating the required flow rate and head for a specific heating or cooling system. This method requires knowledge in the field of hydraulics and thermotechnics.
- Comparison method: involves comparing the technical characteristics of pumps from different manufacturers and choosing the most suitable option. This method is useful for selection if you do not have accurate data on the needs of your heating or cooling system.
- Recommendation method: in this case, you turn to the manufacturer or a specialized company that provides recommendations for selecting a circulation pump for your system.
It is important to consider the pressure and temperature and operating conditions (vibration and noise). This will help choose a pump suitable for your specific situation and ensure the best performance efficiency.
Calculation of Circulation Pump Characteristics
The following formula is used to calculate the characteristics of a circulation pump:
Q = (H1-H2) / (K * √ΔP)
where Q is the fluid flow rate, H1 is the head at the pump inlet, H2 is the head at the pump outlet, K is the coefficient of hydraulic friction in the pipeline, and ΔP is the pressure difference between the inlet and outlet.
This formula allows determining the necessary performance depending on the parameters of the system into which it will be installed.
If you are not confident in your ability to calculate the characteristics of the pump yourself, you can turn to heating and water supply specialists. They will help you choose the right equipment, taking into account all the parameters of the system, and ensure optimal performance and efficiency.
Selection of Circulation Pump by Size
When choosing this equipment, it is important to consider its dimensions so that it corresponds to the hydraulic characteristics of the heating or water supply system. The main criteria to pay attention to are:
- determines the diameter of the pipe to which the pump is connected. Usually, it ranges from 1 to 2 inches (25-50 mm);
- distance between the centers of the inlet and outlet openings of the pump;
- the height of the pump from the base to the top of the housing;
To make the right choice, you need to know the hydraulic parameters of the system (flow rate and head), the length and diameter of the pipes connected to the pump. If you are unsure of your knowledge, it is better to seek help from a specialist.
Cost of Circulation Pumps
The total cost of circulation pumps can vary greatly depending on the brand, model, and characteristics. There are many cheap pumps with similar characteristics to expensive models. But it is important to remember that price does not always reflect quality, and cheap pumps have low performance and a short service life.
On the other hand, pumps from world-leading manufacturers such as ACV may cost significantly more, but their quality and reliability are often higher.
Chinese manufacturers often offer cheap analogs of well-known brands, but their quality and reliability can vary greatly. We recommend buying original pumps from trusted suppliers to avoid potential problems with operation or equipment safety.
Counterfeit circulation pumps are low-quality materials, often using outdated production technologies, they usually do not undergo appropriate testing and do not have a warranty. This leads to:
- unstable pump operation;
- short service life;
- dangerous situations (leaks and damage to the heating system).
Choose equipment from a reputable manufacturer and purchase it from reliable stores, where there is a wide selection of pumps from brands like De Dietrich and others.