W type – clockwise & anticlockwise

W type – clockwise & anticlockwise

W & G type – clockwise & anticlockwise

G type – anticlockwise

G type – anticlockwise

W Type – Clockwise & Anticlockwise

G Type – Anticlockwise

IRG Type – clockwise

Are you looking to buy good circulator pumps from China but overwhelmed by so many options to make the right decision?
This informative FAQ guide mentions almost everything you need to know about buying circulator pumps.
We hope this article could help you make a better-informed purchase decision.
Let’s get started to learn more.

• What is a wet rotor circulator pump?
• Applications of a circulator pump?
• Types of wet rotor circulator pumps in the market.
• What is the general circulator pumps manufacturing process?
  ( How are circulator pumps made?）
• What is the difference between a classic circulator pump and a smart high efficiency pump?
• Do you produce classic circulator pumps or high efficiency circulator pumps?
• Which circulator pump is good for you?
• What is the ErP directive and its effect on circulating pumps?
• What are the benefits of using high efficiency pumps?
• What’s the difference between wet rotor and dry rotor circulator pumps?

Wet rotor circulator pump is characteristic that the rotor is located directly in the fluid that is being pumped. The electric motor is located in a sealed part, where water does not get. The principle of operation of this mechanism is as follows: a rotating rotor accelerates the movement of water. The fluid in which the rotor is located is a coolant and lubricant for the mechanism.

Central Heating:
It is often used to circulate domestic hot water so that a faucet will provide hot water instantly upon demand or keep rooms warm by underground heating systems, solar system, or heat pump.

Water pressure boosting:
Pressure boosting of drinking water supplied from an external source in residential homes and increase water pressure to required levels at showers, taps and other tapping points.

Coolant Circulating:
It can be used to circulate 50% ethylene glycol solution in cooling systems.

Gas Boilers:
It is built in the gas boilers and boost the water pressure inside.

In general, wet rotor circulator pumps can be categorized into 2 types by its Energy Efficiency.

Classic Pump:

It is the first generation of circulator pumps with asynchronous motors. The rotor is made of coiled silicon steel sheet. It usually has 3 manually selectable speed stages.

Smart High Efficiency Pump:

It is new generation of circulator pumps with synchronous motors. The rotor is made of permanent magnet that increases the pump efficiency by 20% . The pump speed is controlled by an integrated frequency converter incorporated in the control box. Multifunction control can be realized easily. Digital display is also available. After all, frequency converter and new materials make the pump save energy power by 80% .

Wet rotor circulator pumps can also be classified in terms of their work application into domestic type and commercial type.

Domestic pump:

The pump head ranges from 4m to 8m, mostly 6m. Flow rate ranges from 2.3 m³/h to 6.9 m³/h according to the room floor space.

Commercial pump:

The pump head ranges from 10m to 20m. Flow rate ranges from 10 m³/h to 30 m³/h. Usually the connection is flange DN40, DN50, DN65.

A complete circulator pumps manufacturing process entails the following 4 processes:
(1) Motor producing process
Silicon steel sheet → Stator core → Stator copper coil winding → Dip coating stator copper coil → Motor with housing

(2) Shield cover producing process
Stainless steel sheet → Cold press molding → shield cover → Shield cover washing

(3) Rotor kit producing process
Silicon steel sheet/permanent magnet → rotor core → shaft into rotor core → rotor rotating balance testing → rotor with impeller & thrust bearings → rotor into shield cover → rotor kit

(4) Pump assembly and testing process
Motor with rotor kit and pump body → Painting → Air tightness test → Install control box → Insulation test and performance test → Packaging

We produce full range of circulator pumps of both classic and high efficiency types.

To choose a suitable circulator pump, you need to find out the volume of the heating system and water, the number of radiators or the area of the underfloor heating. Accordingly, select the required power, referred to as the maximum pressure head, and possibly the number of pumps. In order to install the pump correctly you must also know the pitch and diameter of the connecting threads.

Maybe it sounds a little complicated for a green hand. So we prepared a lead that can help you get a rough idea. Take our pumps for example,
Floor Space ≤ 60 ㎡ ： LE15/4, LE25/4, LE32/4
Floor Space ≤ 100 ㎡ ：LE15/6, LE25/6, LE32/6
Floor Space ≤ 120 ㎡ ： LE15/7, LE25/7, LE32/7
Floor Space ≤ 160 ㎡ ： LE15/8, LE25/8
Floor Space ≤200 ㎡ ： LE32/8, LE20/12, LE25/12, LE25/15

Since 2013, it is only possible to sell high efficiency circulator pumps of Class A in the European Union. So if you are located in EU, you can choose our smart high efficiency pumps of HE series. Of course, the investment will be higher if you buy a high efficiency pump, but energy savings will pay you back many times over.

The Energy-related Products Directive (ErP) 2009/125/EC replaced the Eco-Design Directive (EuP) in November 2009 and impacts all energy-related products sold within the EU. According to the European Commission, an energy-related product is any energy-using product or energy-saving product “having an impact on energy consumption during use.”
With this directive, the European Union regulator laid the groundwork for specific implementing measures affecting a broad range of EuP and ErP.

Current Implementing Measures (IM)

• Circulators
• Electric Motors
• External Power Supply
• Household Refrigerating Appliances
• Non-Directional Household Lamps
• Simple Set Top Boxes
• Standby Off Mode
• Street & Office Lighting
• Televisions

The goal is the reduction of energy along the supply chain: from the design stage throughout production, transport, packaging and so on. Products that comply with this directive are easily recognized by carrying the CE marking. In this case, the CE mark covers product safety and energy efficiency requirements.

Low Power Consumption:
High efficiency provide an 85% to 90% reduction of electrical consumption. Depending on what you pay per kilowatt hour, that electrical savings may translate into $3 to $5 per month during the heating season.

What does that mean? It means that within two, maybe three years after installation, the added cost of the circulator (depending on which one you buy) will be offset by the estimated $28 to $35 you save each heating season.

Instead of using a circulator operating at 80 to 85 watts, you could conceivably satisfy a zone’s pumping requirement at 25 watts, or less.

Intelligent control:

High efficiency pump gives you the full range of Intelligent control mode options which can save time and energy. Installers can select between multiple constant speed, constant pressure and proportional pressure modes as well as AUTO, self-adjusting proportional pressure mode.

Constant speed mode is used when there is a demand for constant flow and constant head. The pump is adjusted to the desired duty point making pump throttling valves, which are traditionally required in this situation, obsolete.

Constant pressure mode is suited for variable flow systems with very low pipe pressure losses, and in open systems where pipe pressure loss is subordinate to static head. Constant pressure mode provides constant pressure to the system. Constant pressure works well when there is very little resistance in the distribution piping. Systems where the distribution occurs in the boiler room right after the circ work well with constant pressure.

Proportional pressure mode is used in circulating systems. The pump continuously adapts its performance to the varying flow demand. In systems where there is significant resistance in the distribution piping like TRV’s or remote zone valve systems, proportional pressure is appropriate. It provides a little more pressure all the time and tapers proportionally in order to always provide enough force to overcome the resistance in the distribution piping.

The AUTO function continuously adjusts the proportional pressure curve and automatically sets a more efficient one, without compromising comfort demands. With this factory setting, in 80% of the installations no manual adjustments are needed.

By matching a circulator’s performance as closely as possible to that specific zone’s flow and head requirement, high efficiency pump can minimize the industry curse of over-pumping and all of the nasty things that does to a system, such as: reduced system ∆T, resulting in boiler short-cycling, reduction of system efficiency, and premature wearing of all moving parts in the combustion and circulation cycle.

Depending on the design, all the pumping units of the heating systems are divided into two types:
-Wet rotor circulator pump
-Dry rotor circulator pump

Wet rotor circulator pump is characteristic that the rotor is located directly in the fluid that is being pumped. The electric motor is located in a sealed part, where water does not get. The principle of operation of this mechanism is as follows: a rotating rotor accelerates the movement of water. The fluid in which the rotor is located is a coolant and lubricant for the mechanism.

Advantages of the wet rotor circulator pumps:

• low noise level;
• no need for lubrication;
• effective way of cooling;
• ease of installation;
• lack of need for maintenance.
• relatively low price of the unit and spare parts;
• long period of service;

In a dry rotor circulator pump, the rotor does not come into contact with the coolant. Its working part is isolated from the engine by means of O-rings, which are made of coal sinter, ceramic or stainless steel. Running pumps with a dry rotor make a lot of noise, which is why they need to be installed in separate rooms with sound insulation. The overall reliability level of dry rotor pumps is lower due to the greater number of seals and the lack of constant lubrication. Cons also include cleanliness requirements and the need for periodic maintenance and lubrication of the rolling seal.

Still got questions? Call, email or, chat, today!