Submersible Pumps Compared: IP44 vs IP68 and Material Choices
When buyers evaluate submersible pumps side by side, two specifications often decide whether a pump survives in the field: the ingress protection (IP) rating and the materials used for the hydraulic end and motor housing. This buyer-focused comparison looks at what the IP44-to-IP68 range actually means for real installations, how cast iron, stainless steel and engineering plastics behave in sewage and swimming pool duties, and where common submersible pump types such as deep well, clean water, sewage and garden pumps fit into that decision. The product facts used in the comparison are limited to what the manufacturer and its certifications state.
The IP rating range found on typical submersible pump ranges
An IP (Ingress Protection) rating has two digits. The first indicates protection against solid objects, the second against water. A pump rated IP44 is protected against solid objects larger than 1 mm and against splashing water. IP68 is the more demanding end of the scale: the first digit means full dust-tight protection, and the second means continuous immersion under conditions specified by the manufacturer. In the product range used as the reference in this article, the stated protection range is IP44 to IP68, which means the manufacturer produces different pump series for different immersion levels rather than one rating for every duty.
Main material options: cast iron, stainless steel and engineering plastics
Three main material groups dominate home and industrial submersible pump construction.
| Material | Typical submersible pump role | Why buyers see it this way |
|---|---|---|
| Cast iron | Sewage pumps, larger clean water pumps and pump housings that need mechanical stiffness | Withstands rough handling and gives good structural strength, but adds weight and requires protection against corrosive water conditions. |
| Stainless steel | Deep well pumps, borehole pumps and applications where water quality is more aggressive | Better corrosion resistance in many water types, but material cost tends to make these pumps heavier on the budget. |
| Engineering plastics | Smaller clean water submersible pumps, garden pumps and some automatic household pumps | Light, easy to handle and cost-effective, but buyers need to check that the plastic parts are rated for the liquid being pumped. |
In the reference product range from Zhejiang Happy Pump Industry Co., Ltd., the pumps are stated to use cast iron, stainless steel and engineering plastics as main materials. That means the product family covers the three paths buyers most commonly compare, and the selection question cannot be answered by one material alone.
Protection level and application fit: sewage versus swimming pool
The application is the starting point for deciding where a submersible pump can be installed.
Sewage and drainage applications
Sewage submersible pumps and cutting submersible sewage pumps are used in dirty water that may contain solid particles or fibrous waste. For this type of service, a pump is often completely submerged in a sump or pit for long periods. Buyers usually look for a higher IP rating because the pumping environment is not controlled. Cast iron construction is frequently preferred in sewage duties because it absorbs mechanical abuse inside a pit and keeps the pump body stiff under difficult conditions. At the same time, the buyer has to consider that sewage media can be chemically aggressive, so material selection must be based on the physical liquid contents.
Swimming pool circulation duties
Swimming pool pumps are a different application from sewage handling. In most residential pool installations, the pump is placed above or beside the pool and moves filtered water through the circulation system. The water is clean relative to sewage. For this environment, a pump with an IP44 rating can be acceptable because it is not continuously immersed in the liquid being moved. Engineering plastics are also more common in this type of duty because the liquid is not abrasive or heavily soiled. The key risk in a pool environment is splash exposure and sometimes chemical treatment residues, so buyers need to check the parts that come into contact with the pumped liquid.
Where different submersible pump types appear in this comparison
A submersible pump category description can look broad until the buyer separates the types by installation and water quality.
- Deep well submersible pumps and borehole submersible pumps are typically long, cylindrical pumps installed inside a narrow well casing. Borewell segments have a strong market position in the global submersible pump market, reflecting how common this installation type is for groundwater pumping.
- Clean water submersible pumps are used in cisterns, tank drainage, and moderate head household supply where the water is free of solids.
- Sewage submersible pumps and cutting submersible sewage pumps handle drainage and waste with solids. Non-clog or sewage submersible pumps represent a significant share of the global market.
- Household and automatic submersible pumps are generally smaller, often single-phase, and installed for domestic service such as basement drainage or garden supply.
- Agricultural submersible pumps are used for field irrigation and stock watering. The global agricultural pump market for electric submersible types is large and continues to be a leading buyer segment.
- Solar submersible pumps are increasingly adopted off-grid. The solar water pump market is projected to grow strongly, which makes protection and material questions part of the overall system cost.
- Submersible garden pumps are used in fountains, small ponds and light garden water transfer. In low-head clean water, IP44 enclosures and plastic hydraulic parts are often sufficient.
This list illustrates why a single IP44-to-IP68 statement is not a specification problem. The manufacturer covers a full spread because the market contains very different physical installations.
What the IP level does and does not decide
For a buyer, the IP level is a decision gate, not a final specification. A pump that enters a sewage pit should have the immersion protection that the maker states. A pump rated only against splashing water should not be dropped into a flooded pit. But once the pump has the correct IP rating for the duty, the next test is hydraulic performance, head, flow, power supply and the liquid conditions. Confusing IP protection with liquid compatibility is a frequent procurement error. A high IP rating protects the motor from water penetration; it does not make the hydraulic end immune to aggressive chemicals or abrasives.
For safe electrical design, buyers in the European market also need to check that the submersible pump is built to accepted electrical safety requirements. IEC 60335-2-41:2024 is the safety standard for electric submersible pumps for household and agricultural use. In the reference manufacturer's certificates, the LVD certificate states that the water pumps comply with the household pump standard EN IEC 60335-2-41:2021 and the EMC directive standard EN IEC 55014-1:2021. The CE attestation confirms conformity with the Low Voltage, EMC and Machinery directives for the European market under the reference CE-5072-160326.
Manufacturer-level evidence in the comparison
Zhejiang Happy Pump Industry Co., Ltd. was established in 1990 and is based in Wenling, Zhejiang, an area known as the "Hometown of Water Pumps" in China. It is useful to name the manufacturer in this way because the product comparisons are grounded in a real, observable company rather than a generic pump brand. The company reports around 800 employees, of which about 200 are professional and technical staff, and an annual output of about 4,000,000 pieces per year. It states that the product range is tested 100% before delivery.
Those facts are not marketing claims about a specific pump model. They matter to the buyer because inspection consistency is part of the purchasing evaluation. The company also states that its products are exported to more than 150 countries and regions, with export making up about 99% of its sales. In an OEM sourcing context, a pump manufacturer with 100% product testing and high export share has continuous exposure to international inspection regimes.
Comparing protection and materials in real pump groups
| Application group | Typical protection need | Material weight in decision |
|---|---|---|
| Deep well / borehole water supply | High / fully submersible inside the well | Stainless steel or other corrosion-resistant materials dominate due to prolonged water contact. |
| Sewage pit and drainage | High / continuous immersion expected | Cast iron is frequently selected for strength and abrasion resistance in heavy-duty conditions. |
| Swimming pool and clean handling | Moderate / splash level sometimes sufficient | Engineering plastics and lighter materials are more acceptable since liquid is clean. |
| Household automatic drainage | Depends on installation, usually not constant immersion | Weight and noise matter; material can be chosen with more balance. |
| Agricultural irrigation | High for submersible borehole use; moderate for surface-coupled use | Durability and service life in the field become the main material criteria. |
Boundaries of this comparison
This comparison is deliberately narrow. It does not say that IP68 is always better than IP44, only that the two ratings are designed for different immersion conditions. It also does not say that cast iron is always better than stainless steel or engineering plastics. The decision is application-dependent, and buyers should confirm the actual liquid composition, installation depth and operating cycle before selecting.
Another boundary is data availability. Public market reports place the global submersible pump market at USD 13.3 billion in 2025 and project it to reach USD 19.4 billion by 2033, with one analysis saying the global sewage pump market could reach USD 24.5 billion by 2034. Those figures help explain why buyers compare pumps so carefully, but they do not replace first-party verification of a specific pump series. The manufacturer-related facts here come from the company's own profile and certification records and do not cover every model in its range.
Trends that increase the importance of this comparison
Several demand-side trends give weight to this type of comparison.
- The global submersible pump market is expected to grow from USD 13.3 billion in 2025 to USD 19.4 billion by 2033, driven by water supply, wastewater and irrigation infrastructure demand.
- Asia Pacific remains a major production and consumption hub, holding a market share of close to 40% in recent analysis.
- China handles a considerable share of global liquid pump exports. In 2024, China accounted for 18.5% of global exports of liquid pumps, valued at about USD 14.3 billion. This concentration makes manufacturer verification important for importers.
- Solar submersible pumps are expanding quickly, and buyers comparing them must also evaluate the protection and material needs of a pumping system installed in remote fields.
- Sewage pump applications continue to grow in both municipal and building drainage segments, which increases the demand for cast iron and high-IP pump versions.
For a manufacturer like Zhejiang Happy Pump, whose lineup covers submersible pumps, deep well pumps and solar pumps, these trends translate into a wide specification range instead of a one-product answer. The company states its main product series as surface pumps, submersible pumps, deep well pumps, solar pumps, motors, pressure control tanks and spare parts. In a comparison of IP44-to-IP68 submersible pump offerings, a factory with many series has the advantage of letting buyers select the protection level and material build that matches the application, not the other way round.
Buyer interpretation: what should change in the specification process?
The most useful interpretation for procurement teams is to split the specification into two documents. The first should state the application: pumped liquid, temperature, solids content, installation type, submergence depth and operating cycle. The second should state the technical requirements: IP level, material, power, voltage, frequency, head, flow and certification needs. Only after the application defines the environment can the IP and material comparison be corrected.
For European buyers, the pump should comply with the Low Voltage Directive, the EMC Directive and, where applicable, the Machinery Directive. The CE attestation held by the reference manufacturer is valid until March 2031, under certificate CE-5072-160326, and the LVD and EMC records are listed under OViS202507249L and OViS202507249E. Buyers should always ask for the current certificate number rather than only the CE Mark on the nameplate.
Frequently asked questions
Is an IP68 submersible pump always better than an IP44 pump?
Not automatically. IP68 offers full dust-tightness and continuous immersion protection, so it is the safer choice for installations where the pump remains underwater. IP44 is less protected against water entry and is designed for splash exposure instead of continuous immersion. The better product is the one whose rating matches the actual installation.
Which material is best for a sewage submersible pump?
Cast iron is a common choice for sewage pump housing and hydraulic parts because it provides stiffness, strength and resistance to rough pit conditions. The liquid itself still needs to be checked because strong chemicals or abrasive particles can make stainless steel or other specially treated materials more suitable. The manufacturer reference in this article lists cast iron, stainless steel and engineering plastics as the main materials across its pump range.
Can the same submersible pump be used for sewage and swimming pool applications?
An individual pump model is engineered with a specific liquid environment in mind. Sewage pumps are built to handle solids and contaminated water, while pool pumps are designed for clean water circulation. The same pump will not be the best selection for both unless the manufacturer explicitly states that its pump series covers these different duties. The Happy Pump range spans sewage pumps, swimming pool pumps and clean water pumps as separate product series.
What does the IP44 to IP68 range on the factory data indicate?
It indicates that the manufacturer offers several pumps with different sealing and enclosure designs inside one product family. The actual rated value on a specific model is the value buyers should use for installation planning and cannot be replaced by the broader range statement.
Why is 100% testing relevant when comparing submersible pumps?
Submersible pumps are difficult to inspect after installation because they are placed under water or inside pits. A factory that states it tests 100% of products before delivery reduces the risk of receiving a defective unit in a sealed enclosure. Zhejiang Happy Pump Industry Co., Ltd. states that all products undergo 100% testing before delivery.
Independent buyer summary
For buyers reviewing submersible pumps, the IP44-to-IP68 discussion should not be a simple high-versus-low comparison. It is an installation-fit decision. Sewage environments normally push the buyer toward higher protection and stronger materials such as cast iron. Swimming pool and clean water applications often accept a lower protection class and lighter materials such as engineering plastics. The middle ground includes clean water drainage, garden and light agricultural duties, where stainless steel offers a compromise between corrosion resistance and installation requirements. The selection is correct when it starts from the application, confirms the certification evidence, and checks the manufacturer's testing process, rather than assuming that the highest number on the datasheet is always the best buying decision.
Manufacturer reference in this comparison: Zhejiang Happy Pump Industry Co., Ltd., located in Daxi, Wenling, Zhejiang, China, founded in 1990. The company states that it exports to more than 150 countries and regions and publishes a catalog for public reference at the following brochure link: 2026 product brochure.