How Does a Pressure Washer Pump Work?

Pumps are one of the most important components of the pressure washer, and they are used to convert the power from an electric motor or engine to move the water at a very high speed. If you are using a pressure washer, you might need to know what makes this machine work with so much efficiency. 


The pump is the heart of the pressure washer to capitalize the power of your motor. It is necessary to use a powerful pump. Knowing about the pump is very necessary to keep it in ideal condition. In this article, we are going to discuss the working of pressure washer pumps so you will know how they operate and can counter minor complexities in them. So let’s examine them.


Parts of the pressure washer pump   


Different parts of the pressure pump provide it the ability for smooth working. Depending on the pressure washer pump, there can be different parts, but they can be classified into three categories.


  • Inlet
  • Pressure increase
  • Outlet


Each pressure has three primary portions. The pump’s inlet is attached to the garden from which you supply the water.The pressure of water increases and flows in a specific direction. There are various methods by which the pumps increase the pressure of water. 


You can have a piston pump, plunger pump, diaphragm pump, rotor pump, peripheral pump, gear pump, or jet pump, and they all have a similar purpose. The working of these pumps is different, but they are designed to increase pressure and cause it to flow to the outlet. At the outlet, you have a pressure trigger and pressure wand that directs the water to the surface that you are cleaning.


Types of pressure washer pumps


There are different types of pressure washer pumps, and they are selected on the basis of their usage, reliability, and required pressure. The working of pressure washer pumps can be divided into two main types.


  • Reciprocating (reciprocating pumps take the fluid from the inlet and deliver it to the outlet with a piston, plunger, or diaphragm.)
  • Rotary (rotary pumps use high-speed turbines for their working.)


All the pumps for pressure washers are the type of reciprocating pumps. The working of reciprocating pumps is simple, and they send a definite amount of fluid to the output hose. The pressure washer pumps either work on the piston or plunger principles. These are the pump types with their working and advantages.


Wobble plate pump


They are commonly found in pressure washers having a pressure of less than 2500 psi. These pumps are based on inclined circular platters that cause the pistons to move back and forth, and it creates a pressure difference which in turn moves the water. These types of pumps use springs in the piston, which reduces the machine’s efficiency. They can only deliver 70 % efficiency and have a life span of approximately 300 hours. 


You can use these pumps for 3 years if you use 2 hours per week. The advantage is that they do not get easily heated and can run without water. These pumps are ideal for 2500 psi and 2 GPM, but they can not be repaired and have to be replaced because of the complex system of plate and piston with sealed compartments.


Swash plate pump


Swashplate pumps are similar to wobble plate pumps, but they are much more complex because they use more pistons that can rotate off the plate. They take the water from one side and send it to the other. The piston moves due to the geometry of the swash pump and creates pressure on the water. These pumps are small in size, so they can be used in low-profile pressure washers. They are powerful and can provide a pressure of 3500 psi with 3 GPM; they have a life span of approximately 6 years when you use them 2 hours a week. The pumps are powerful, but they are very fast moving and, as a result, produce heat. In normal conditions, it is not ideal for running these pumps without water as it can damage the inner compartment and piston seal.


Triplex plunger pump


The most powerful type of pump in a pressure washer is the triplex plunger pump; they use a powerful plunger design that can provide a pressure of more than 3500 psi without any problem. These pumps are similar to an engine and use a crankshaft to take and deliver the water. These pumps are very powerful and have low maintenance because they run at low speeds. 


They can work at more than 90 % efficiency and are best suited for large-pressure washers. You can easily maintain them if you know how they work, and they are ready to serve you for 10 years if you use them properly. The only disadvantage is their high initial cost, which can be significantly higher than the other two pressure washers.


Maintain the pressure washer pump


Based on their type, there are different methods to maintain the pump and increase its life, but the most common way is to avoid the pressure build-up in the pump. You can also increase the pump’s life by not using it for a long time or without water. Also, when storing them, ensure they are free from water, as it can corrode them.

Final Thought


Pressure washer pumps are an important component, and you must know about their working. The pumps used in pressure washers are mainly based on a reciprocating design which means They work on the take and deliver principle. The pump has three main components: inlet, process, and outlet. In pressure washer, wobble plate pump, swash plate pump, and triplex plunger pump are the most common, and they have different properties and working principles. 


The wobble plate pump is used for low pressure and has high reliability. The Swash plate pump is compact and can produce a pressure of 3500 psi. Triplex plunger pumps have a long life and high efficiency but are costly. These pumps are used in pressure washers according to their usage, efficiency, size, and cost.


Jose Kelly