Self-priming Pump
Sealless self-priming pump is an efficient, environmentally friendly and maintenance-free fluid conveying equipment, designed for harsh working conditions with no leakage and self-priming start, suitable for the conveying of corrosive, flammable, explosive, toxic or high-purity media. The following are its core functions, structural features and scope of application:
I. Product Overview
Core functions:
Sealless design: Adopting magnetic coupling drive or shielded motor technology, completely eliminating mechanical seals and completely eliminating the risk of leakage.
Self-priming ability: No need to prime the pump, it can automatically suck in liquid (the suction range is usually 3-8 meters, depending on the model and medium characteristics).
Intelligent control: integrated automatic start and stop, overload protection, dry run protection and other functions to achieve unattended operation.
Applicable media:
Water, wastewater, acid, alkali, salt solution (such as hydrochloric acid, sulfuric acid, brine, etc.);
Organic solvents, oils, liquid chemicals;
High-purity pharmaceutical and food-grade media (must meet sanitary material standards).
2. Structure and working principle
1. Core structure
Drive mode:
Magnetic drive: The outer magnetic rotor and the inner magnetic rotor transmit torque through the isolation sleeve to achieve complete sealing.
Shielded motor: The motor and the pump body are integrated, the rotor is in contact with the medium but isolated by the shielding sleeve, and there is no dynamic sealing point.
Pump body material:
Corrosion-resistant metal: carbon steel, 316L stainless steel, duplex steel, Hastelloy, titanium, etc.;
Non-metal: fluoroplastic (PTFE, PFA), ceramic lining (wear-resistant and corrosion-resistant).
Self-priming structure:
Built-in gas-liquid separation chamber and reflux channel, through high-speed rotation to form negative pressure, to achieve rapid self-priming.
2. Working principle
Self-priming stage: After starting, the impeller rotates at high speed, the gas and liquid in the pump chamber are mixed and discharged, forming a vacuum suction medium.
Stable delivery: After sucking in the liquid, the pump enters the normal centrifugal delivery state and continuously outputs a stable flow rate.
Shutdown protection: The one-way valve automatically closes when shutting down to prevent the medium from flowing back and keep the pump chamber full for the next self-priming.
3. Product features and advantages
Zero leakage, safe and reliable:
No mechanical seal design to avoid medium leakage, in line with environmental protection and explosion-proof requirements (Ex certification optional).
Efficient self-priming:
Short self-priming time (usually ≤2 minutes), high suction range, adaptable to complex working conditions (such as tank truck unloading, underground pool suction).
Corrosion and high temperature resistance:
A wide range of materials can be selected, with a maximum temperature resistance of up to 90°C (special design required), and a pressure resistance of ≤2.5MPa.
Low maintenance and long life:
No vulnerable seals, maintenance costs are reduced by more than 50%, and the average life can reach 5-10 years.
Intelligent control:
Support PLC/IoT remote monitoring, real-time feedback of operating status (flow, temperature, pressure, etc.).
4. Typical application areas
Industry Application scenarios
Agricultural irrigation
Chemical/petrochemical Acid, alkali and salt transportation, reactor feeding, waste liquid recovery, tank emptying
Environmental water treatment Sewage lifting, corrosive wastewater treatment, agent addition
Pharmaceutical/food High-purity solvent transfer, CIP/SIP cleaning system, sterile medium transportation (sanitary design required)
Electroplating/metallurgy Electrolyte circulation, pickling liquid transportation, high-temperature quenching liquid transfer
Energy Offshore platform oily wastewater treatment, nuclear power plant coolant circulation (special certification required)
5. Selection and use precautions
Key selection parameters:
Medium characteristics (concentration, temperature, corrosiveness, solid content);
Flow rate (m³/h), head (m), self-priming height requirements;
Power supply conditions (voltage, frequency), explosion-proof level (such as Ex d IIB T4).
Installation and maintenance:
The inlet pipe should be as short and straight as possible, and the number of elbows should be reduced to improve the self-priming efficiency;
Regularly check the air gap of the magnetic coupler or the integrity of the shielding sleeve to prevent demagnetization or wear;
Drain the pump cavity when it is not used for a long time to avoid blockage caused by crystallization or solidification.
Contraindicated working conditions:
The medium contains hard particles (need to install a filter or use wear-resistant materials);
Extreme viscosity (such as >500cP) or easy crystallization medium (need insulation or flushing design).
5. Technical parameter examples (taking a certain model as an example)
Parameters Index
Flow range 1-7000m³/h
Lift range 10-120m
Self-priming height ≤7m (clean water condition)
Medium temperature -10ºC~70ºC (conventional type)
Rated pressure ≤1.6MPa
Material options 304/316L/2205/Hastelloy/PTFE lining
Protection level IP55/IP65 (optional)
VII. Frequently asked questions (FAQ)
Q1: Can sealless pumps completely replace traditional centrifugal pumps?
Suitable for scenes with high anti-leakage requirements, ordinary centrifugal pumps can be preferred for conventional clean water conditions.
Q2: Possible causes of self-priming failure?
Leakage in the inlet pipe, high viscosity of the medium, and residual gas in the pump chamber that has not been exhausted.
Q3: Does it support idling?
Short-term idling is harmless (magnetic pump characteristics), but long-term dry running should be avoided to cause overheating.
Summary: The seal-less self-priming pump has zero leakage, convenient self-priming and corrosion resistance as its core advantages, and is an ideal choice for industries such as chemical industry and environmental protection. When selecting a pump, you need to consider the characteristics of the medium, working conditions and cost budget, and consult a professional supplier for customized design if necessary.
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