What kind of chemical pump should be chosen for high-temperature boiler water with a temperature of 165 degrees Celsius ？

For boiler feed water pumps, high-temperature and high-pressure working conditions are often required. 

When the outlet pressure is high and the medium has a relatively high temperature, how should the pump be safely selected?

When choosing a chemical pump for transporting high-temperature boiler water at a temperature of 165 degrees Celsius, it is necessary to pay close attention to the pump's high-temperature resistance performance, material compatibility, and the reliability of the sealing system. 

The following are selection suggestions based on relevant engineering practices:

1. The type of ‌ pump is selected as ‌

centrifugal pump ‌ : For high-temperature boiler water (which is a high-temperature liquid at 165°C), centrifugal pumps are a common choice, especially single-stage centrifugal pumps.  Centrifugal pumps are suitable for conveying clean water or similar liquids and can still maintain stable operation at high temperatures. If the water in the boiler is pure

For water or low-corrosive media, standard centrifugal pumps can meet the requirements.

Precautions ‌ : When the temperature exceeds 100°C, it is necessary to ensure that the net positive suction head (NPSH) of the pump is sufficient to avoid cavitation problems. For high-temperature media, it is recommended to choose pump types with high-temperature resistant designs, such as centrifugal pumps with cooling jackets or special seals.

2. Material selection ‌

Pump body and flow-through components ‌ : High-temperature boiler water may be corrosive (such as containing oxygen or impurities), so the flow-through components of the pump (such as impellers and pump casings) should be made of materials that are resistant to high temperatures and corrosion. Common choices include: ‌ stainless steel ‌ (such as 304 or 316 stainless steel) :

Suitable for general corrosive environments.

duplex stainless steel or nickel-based alloy ‌ : If the boiler water is highly corrosive, more corrosion-resistant materials should be selected. ‌

Sealing material ‌ : Sealing parts are prone to aging at high temperatures. It is recommended to use high-temperature resistant mechanical seals, such as silicon carbide-graphite sealing rings, and combine them with a cooling system (such as a sealing flushing scheme) to extend their service life. ‌

3. sealing system ‌

mechanical seal ‌ : It is the first choice for high-temperature applications due to its low leakage and long service life. Youdaoplaceholder0 1 For media at 165°C, high-temperature resistant sealing materials (such as fluororubber or polytetrafluoroethylene) should be selected, and the addition of sealing flushing or cooling devices should be considered.

Avoid packing seals ‌ : Packing seals tend to dry up and fail at high temperatures and are generally not recommended for high-temperature boiler water. ‌

4. Other key parameters ‌

Head and flow rate ‌ : Determine the head and flow rate of the pump based on the actual requirements of the boiler system. When selecting the type, the rated head of the pump should be 1.05 to 1.1 times the required head of the system, and the flow rate should be 1.1 to 1.15 times the maximum flow rate. ‌

Prime mover matching ‌ : Select the prime mover (such as motor) based on the shaft power of the pump, and take into account the power margin coefficient and transmission efficiency. ‌

standby rate ‌ : Boiler systems typically require high reliability. It is recommended to adopt a 100% standby rate (i.e., one in use and one on standby). ‌

5. standards and specifications ‌

Select pumps that comply with API 610 (Standard for Centrifugal pumps for petroleum, Heavy Chemical and Gas Industries) or GB/T 5656 (ISO 5199 standard). These standards have clear regulations on the design, manufacture and inspection of high-temperature pumps, which can ensure safety and service life. ‌

Summary and suggestions

For high-temperature boiler water at 165°C, priority should be given to ‌ high-temperature resistant centrifugal pumps ‌, with materials selected as ‌ stainless steel  or corrosion-resistant alloy ‌. The sealing system should adopt ‌ mechanical seals and be equipped with cooling measures ‌. At the same time, strictly check the net positive suction head, head and flow rate, and follow relevant standards. If the boiler water contains impurities or is highly corrosive, it is recommended to consult the pump supplier for customized selection.

Note: The actual selection should be calculated in detail based on specific process parameters (such as pressure, medium composition, and flow rate variations). If necessary, refer to the samples from ATACH Pump Factory or the professional engineering manual of ATACH Pump Industry.