Group 25 - Pressure Washer

Revision as of 00:34, 30 October 2009

Members:
Alex Borsuk
Joe Kneating
Scott Literman
Rich Seider
Kevin Walczyk

Contact: Kevin Walczyk

Gate 1

Information on the work proposal, management proposal, and schedule for this project will be available here[1]

Initial Product Assessment

The product being evaluated is a pressure washer. The pressure washer uses a high velocity stream of water to blast unwanted dirt, grime and other substances from almost any surface. It is designed to make washing exterior walls, walkways, driveways and other surface faster and easier than conventional cleaning methods.

• This specific pressure washer is intended mainly for home use because of its smaller size. Larger pressure washers with bigger engines, stronger pumps, and the ability to heat water are used by professionals.
  
  
• This product's general purpose is cleaning. This model features different shaped nozzle heads which can easily be switched, giving the optimal spray pattern for almost any cleaning job.
  
  

Our group will focus on the water pump component of the pressure washer. This device increases the pressure of the supply water before it reaches the nozzle. The pump for this model pressure washer is a reciprocating piston design, using either static or dynamic seals. The pistons reciprocate rapidly, drawing water in to the cylinder and expelling it higher pressure. The water then travels through the hose and out of the hand-held trigger nozzle. The small diameter of the nozzle creates a high-velocity, low-volume stream of water.

Considered as a system, the pressure washer relies on several energy conversions:

• The mechanical shaft energy is transferred from the engine to the compressor’s pistons. These pistons then use their kinetic energy to pressurize the water forcing it out of the nozzle at a high velocity.
  
  

Our product is fully functional and is able to start and run.

• The pressure washer runs very smoothly. It starts easily with a single "pull" and does not stall or hesitate while in use.
  
  
• We are not experiencing any difficulties with the product this time. The product works as specified.
  
  

The water pump component is not a very complex machine. On a scale from one to ten, one being a person holding their finger over the end of a hose and a ten being a full sized fire engine, our compressor would be about a four.

Not including the fasteners which there are about twenty five of, the pump has about twenty parts. The main components of the pump include the manifold, pressure release, pressure valve, two bearings, an outer shell made of four sections, three inner pistons, a crankshaft, a water filter, and approximately seven or eight parts on the inside which are not visible before dissection.

• Exterior components like the outer shell, water filter and fasteners must withstand corrosion, vibration, and abuse and are therefore simple and robust. Internal components include many moving parts needed to pressurize the water and are generally more complicated. There is an assembly on the inside of the shell which is similar to that of a valve train on an internal combustion engine, which is slightly more complex.
  
  

Our compressor is made of four main materials. They are brass, aluminum, steel and plastic.

• The manifold is made brass. We know this because it has a distinct yellowish color and is non-magnetic. The outer shell of the compressor is made of aluminum. This is obvious because of its lighter weight, non-magnetism, and distinct white oxide layer. There are also plastic components present on the assembly, such as the pressure valve and oil plug.
  
  
• We can assume that some of the inner parts of this compressor are made of steel. One of these parts is the compressor's crank shaft.
  
  

If we owned this product, we would be satisfied customers. The pressure washer is easy to move into position, has a high psi output, and functions as intended.

• The pressure washer is very comfortable to use. It has wheels on the bottom making movement very easy to otherwise hard to get to locations. It also has a very long spray hose making it easier to reach difficult places. The handle to the sprayer itself has a hand grip making long jobs more comfortable.
  
  
• Our product is very easy to use. It has a very reliable pull start motor that starts easily and runs well. Using the pressure washer once it is started is very simple. All you have to do is point the nozzle at your target area, pull the trigger and wait for the powerful blast of water.
  
  

The pressure washer requires very little maintenance. Engine and pump oil must be changed regularly and the air cleaner and water screen must be kept clean and free of debris.

Some alternatives to this model pressure washer include different size pressure washers and pressure washers that run on electricity instead of gasoline/diesel.

• The main advantage of having an electric pressure washer is its lower retail price and ability to use indoors. The electric powered pressure washers are cheaper than their gasoline counterparts. However, larger, more powerful electric units may cost as much as their gasoline counterparts. Operating a gasoline/diesel pressure washer in a confined area is dangerous because of carbon monoxide poisoning from the exhaust. Electric pressure washers have no emissions, and thus, are safe to operate anywhere.
  
  
• The main disadvantage of having an electric pressure washer is a less powerful water stream and limited range. The power cord limits the range of the washer whereas the gasoline models can go anywhere.

Gate 2

Causes for Corrective Action

Product Dissection Plan

Product Dissection Images

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Gate 3

coming soon!