horizontal deep well pump

When they say “deep-well pump?”, the first thing that comes to mind is a vertical submersible design. But this is only part of the picture.Horizontal deep well pumpis a separate class of devices, and its use is often associated with specific conditions where the classic submersible option is not suitable or is not optimal. Many people mistakenly believe that since the pump is horizontal, its intake depth is small. This is not always the case. It all depends on the design of the system and, first of all, on the type and location of the suction pipe. In our workshop atZhejiang Yangzijiang Pumping Industry Co.,LtdWe are just faced with requests for such solutions, especially for stationary water supply systems from deep wells or wells with high flow rates, but where lowering a vertical unit is impossible or impractical.

Design specifics and where it works

The main difference is, of course, the location of the shaft and the method of supplying fluid. If in a classic submersible pump the motor and impeller are located in the same vertical axis in the water column, here the motor stands on the surface, and the suction line goes down. The pumping unit itself is mounted horizontally, often in a caisson or a separate room. The key element is creating and maintaining a vacuum in the suction line. This is where all the main “pains” come from.

In practice, we at Yangtzejiang Pump most often use powerfulhorizontal multistage centrifugal pumps. Why multi-stage? Because lifting from a depth of 30-50 meters or more with a horizontal pump housing requires serious pressure, which is easier and more reliable to create in several successive stages. A single-stage centrifugal pump here simply will not achieve the required parameters, or will work at the limit, with noise and the risk of cavitation.

An important point that is often overlooked during design is the diameter and material of the suction pipe. It must be absolutely sealed, and its diameter is often taken a size larger than the pressure pipe of the pump itself. This reduces hydraulic losses and delays the onset of cavitation. We have seen cases where the pump refused to pump from the calculated depth precisely because the suction line was narrowed or slightly sucking in air. They were looking for a fault in the unit itself, but the problem was ten meters of HDPE pipe with a microcrack.

Starting and dry running problems

The biggest headache when operating a horizontal deep suction design is the initial startup. The pump and suction pipe must be filled with water. If the well is deep, a simple filler hole is not enough. You have to install vacuum pumps to pre-evacuate air or use ejector circuits. This complicates and increases the cost of the system. In ourself-priming pumpsWe tried to integrate this function, but for greater depths (over 25 meters) the efficiency drops sharply. This is physics, you can't argue with it.

This leads to the second problem - the risk of running dry. If for some reason the water level in the source drops below the suction pipe, the pump instantly loses water and overheats. For a vertical submersible pump, a level sensor is a standard option. For a horizontal one with an external suction, a separate monitoring system must be organized, and the sensor must be lowered into the well itself. Customers often save money on this automation, and then end up with expensive repairs to the impeller and seals.

We had an illustrative case at one of the agricultural enterprises. We installed our horizontal multistage pump for irrigation from a deep artesian well. Everything was installed, but they “forgot” about the level sensor. At the height of the season, the pump pumped out the dynamic level and went “dry”. and jammed. We took it apart - there was melted plastic in the impeller chamber from overheating. We had to change the entire flow path. Now we always insist on protection.

Materials and durability in aggressive environments

Not all tasks are clean water. Often it is necessary to pump out groundwater, which can be aggressive, or technical fluids. This is where the advantage of the horizontal design becomes more clear. It is easier to connect additional flushing systems to a pump located in an accessible place, and it is easier to maintain mechanical seals. Bour company, with its eight complete production lines, we can offer stainless steel flow parts or even a complete set for such cases.plastic chemical pumpshorizontal type, if the medium is particularly caustic.

But there is a nuance. In the case of deep pumping of aggressive liquids, the material of the suction pipe becomes critical. You can’t install regular steel - it will rot. HDPE or polypropylene are also not always an option due to pressure. We usually recommend pipes made from food grade stainless steel or with an internal fluoroplastic coating. This, of course, seriously impacts the budget, but the alternative is constant repairs and downtime.

An interesting experience was with pumping condensate from mine drainage. The water was acidic, with suspended matter. The vertical submersible pump quickly failed due to abrasive wear. We switched to a scheme with horizontalhorizontal deep well pumpand an intermediate settling tank. The pump itself pumped the already settled liquid, and only a simple vortex pump on a cable was lowered into the well for the initial lift. The system has become cumbersome, but its resource has increased significantly.

Service and maintainability: the main trump card

This is where the horizontal layout beats submersible options outright. Everything is visible, everything is accessible. Replacing the stuffing box seal with mechanical mechanical seals, checking clearances, and preventative replacement of bearings - all this is done in a couple of hours without lifting the entire unit from the depths. For industrial facilities, where stopping the water supply means shop downtime, this is a decisive factor. Our production clients often choose this particular scheme, despite the more complex installation, precisely because of the ease of maintenance.

We assemble these pumps on our production lines with modularity in mind. For example, if one stage in a multistage pump fails, there is no need to replace the entire casing. It is enough to remove the cover and replace the chamber with the impeller. This significantly reduces the cost of repairs for the customer. For submersible analogues, such repairs are often simply unprofitable - it’s easier to buy a new one.

Spare parts should also be available. We at Yangtzejiang Pump try to unify the most wearing elements - shafts, bearing units, seals - for different models of horizontal pumps. This allows the client to create a small repair kit in stock and not depend on urgent deliveries from abroad. In the conditions of current logistics, this is not just convenience, but a necessity.

When a horizontal deep well pump is not the best choice

Despite all the advantages, there are situations where it is better to abandon such a scheme immediately. The first is limited space. If it is not possible to place a pumping station with a horizontal unit near the well (in a house, caisson, pavilion), then the project is doomed. The second is a very large depth (say, over 80 meters). The hydraulic resistance in the suction pipe will become colossal, the efficiency of the system will drop, and the risk of cavitation will become permanent. There is only a submersible option here.

Also, it should not be considered for domestic wells of small diameter (less than 110 mm). Just don't put a suction pipe of the required diameter there along with a check valve and filter. Or lower it, but the well flow will be insufficient to provide the required pump flow.

As a result, the choice between a submersible and horizontal deep-well pump is always a compromise and an engineering calculation. There is no universal answer. You need to look at the depth, flow rate, required pressure, water chemistry, accessibility for maintenance and budget. Our enterpriseZhejiang Yangzijiang Pumping Industry Co.,Ltd, manufactures both types of equipment, so we can make an unbiased recommendation. Often the right solution is a hybrid system, which takes advantage of both schemes. But this is a topic for another conversation.