Parts Of A Pressure Washer
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Motor (Gasoline, Diesel or Electric)
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THE PRESSURE WASHER MOTOR Different sorts of motors are used for different types of pressure washers. It may also depend on the type and location of the applications. Most high power washers used in industrial works, commonly use gasoline or diesel motors. Because most industrial cleaning requires great amount of time, these motors could run much longer without overheating compared to their electric counterpart. And since most industrial works are done outdoors; and sometimes or mostly offsite, where there are no available electricity. The ones with electric motors are mostly used for light to moderate washing works (e.g. house, car, and small boats) and are the most excellent used for indoor applications because these motors do not emit harmful fumes. |
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HIGH PRESSURE PUMP You've now arrived at the "core" of the system, the high pressure pump. All are positive displacement reciprocating pumps either piston or plunger types. Plunger pumps are the most efficient and have a longer life, therefore they are the most commonly employed pumps found on a quality power washer today. |
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These pumps are incredibly robust and virtually trouble free when properly maintained. Most people suspect the pump first when experiencing a problem but amazingly 90% of problems can be traced to causes other than the pump. |
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HIGH PRESSURE HOSE A high pressure hose is composed of an inner tube in which the water flows. This is wrapped in either a single or a double braid of wire mesh. This is in turn surrounded by a rubber outer cover. The cheaper hoses are covered in a thermoplastic material the better hoses have rubber covers. Most hoses are manufactured with burst ratings 4X their rated working pressure. When matching hoses to machines try to use a hose rated slightly higher than the psi rating of your machine. It will last longer. Typical psi ratings are 3000psi, 4000 psi, 4500 psi, 5000psi and 6,000 psi. 3,000 and 4,000 psi hoses are generally single braid while 5,000 psi and above are virtually always double braided (2-wire). |
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A good pressure washer hose is the same design principle as a hydraulic hose. The basic construction is as follows:
Exception: The most notable exception is in the case of sewer jetting. In this case the pressure washer is designed to unblock and clean sewer lines. For this application 1/4" and 1/8" thermoplastic hoses are an advantage due to their ability to make extreme bends within pipes. TIP: If you are planning to use 100 ft or more hose continuously don't buy a 100 ft hose, buy two or more 50 ft hoses and link them together the reason being that if a hose goes bad or wears out you can keep working and you don't lose an extremely expensive hose. A black or red rubber hose can leave marks on surfaces, this can be a concern when pressure washing roof tiles or when doing flat work on concrete. In these cases use blue or gray covers these do not leave marks or scuffs and are referred to as "non-marking hose". Yellow coverings are typically made so that the hose is more resistant to the effects of oil, grease, and animal fats these are often used in rendering plants and other industrial applications. If you are working at heights, remember that all the weight of the pressure washer hoses when filled with water can be pulling on the hose fitting. The best manufacturers sell pressure washer hoses that are skived before coupling. Skiving means the outside rubber cover is partially removed to allow the metal fitting to be crimped to the wire braiding of the hose. This process provides a solid metal to metal solution with good strength. |
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TRIGGER GUNS Considering there are numerous styles of pressure washers, the appropriate trigger gun should complement the whole pressure washer to maximize it for best use and there are also different styles available to pressure washers today. • Pistol Style Guns Trigger guns that stop the water flow are the most commonly used guns in power washer systems equipped with unloader valves. Front entry guns are common on the lesser priced units and rear entry guns are far and away the most popular. Rear entry guns do a better job of keeping the hose out of the operators' way and are better balanced. These guns control the water flow via a spring, ball and seat which are actuated by the trigger. When the trigger is released the ball is pressed against the seat by the spring and water, aided by a check valve in the outlet of the unloader. Water is "trapped" in the hose under pressure and the pump enters bypass mode. With this setup you will experience some "kickback" when you squeeze the trigger so be careful when using ladders and other types of access equipment. Dump Guns and open guns are operated without unloader valves because they don’t stop water flow. The standard pressure washer trigger gun which almost every manufacturer supplies, either a front or rear style pistol gun which stops the flow of water and necessitates the need for an unloader valve. These guns have long been considered to be the industry the standard.
HOW PRESSURE WASHER TRIGGER GUNS WORK Generally the gun will have a 3/8" inlet port where the hose is attached and a 1/4" outlet port to the wand/lance.(this is when 3/8" pressure hose is used.) When the trigger is released the gun is said to be in “closed” position stopping the flow of water. When the trigger is squeezed it is in “open” position directing water to the nozzle once again. These trigger guns control water flow by means of a spring, ball and seat. The trigger controls the on/off of the water flow. When the trigger is released the ball inside the gun is forced to seal in the seat by the spring and the water flow. This effectively stops the flow of water and sends the unloader valve into bypass mode. When the trigger is again squeezed the flow of water and spring force the ball from the seat and water is once again directed to the high pressure nozzle. Pressure washer trigger guns are designed for safety. The design of a trigger gun allows it to go to closed position if the operator loses control or drops it. This is the safety mechanism of the trigger gun. Pressure washers, especially that of industrial type can discharge fluid at a whopping 31,000 psi, and if you happen to drop and lose control of a trigger gun, this may have damaging consequences. There was once a report that a Pressure Washer rental was sued by a renter who claimed he lost control of the gun and was “cut open” from mid-thigh to his chest causing him to be unable to work for an extended period of time. As a result we had 25+ trigger guns impounded as evidence. Investigators later learned that this “roof cleaner” regularly used tennis balls to keep the trigger gun open to avoid the “hand fatigue” that can be caused by squeezing a trigger for an extended period of time. Although today’s pressure washer trigger guns are well designed for safety, don’t negate these safety features by using tennis balls, duct tape or some other method to artificially hold the trigger. Instead look into purchasing an “easy pull” pistol style trigger gun. These are designed to require a much lesser force to pull the trigger than a standard style gun. |
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THE UNLOADER VALVE This is the main "safety" in your power washer system. The most commonly used is the "pressure actuated" type valve. When the pressure gun trigger is released the valve senses the pressure build up and like a "traffic cop" it diverts the water flow from the pump outlet back into the inlet side of the pump this is called "bypass mode." Without this critical component this closed-gun situation would build pressure to the point where it would stall the power source, rupture the gun, hose or even the pump itself. The most basic function of the unloader is to act as a "traffic cop" to the water flow in your system. Depending on the type of valve it will either sense "pressure build" or "reduction in flow". Depending on the type, when one of these conditions is met the unloader will then actuate to divert the water flow back to the inlet side of the pressure pump, where it will circulate through the pump back to the inlet side of the valve to the inlet side of the pump again in what is called a bypass loop when this is occurring the pump is said to be in "bypass mode" and the unloader valve is said to be "cycling". This scenario ends when the trigger is squeezed alerting the unloader valve to redirect the flow to the high pressure nozzle once again. While this may seem to be problem solved it is not without risks. When the water flow is in bypass new cool water is not entering the system. The moving parts in the pump are creating friction which produces heat that is transferred to the water flow in bypass. Since a limited amount of water is in bypass this transfer of heat can occur quickly. Most pumps are designed to handle water temperatures of 140 F. When the water in bypass reaches 155? F damage to the pump will begin. Damage can occur to the pump packings, plungers and seals and even to the short bypass hose in external bypass setups. It is a good idea to have a pump with a thermal relief valve to offer some protection against excessive heat buildup. It is a better idea not to leave a pump in bypass mode for more than 2-3 minutes, by simply squeezing the trigger gun you will introduce new cool water into the system. There are three types of pressure washer unloader valves. |
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These pressure washer nozzles are color coded to indicate what pattern (degree) of fan spray they produce. Although colors may vary depending on the manufacturers, described below are what is commonly used as the industry standard. |
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The red tip is the zero degree nozzles - these pressure washer nozzles produce a pencil point pattern, there is no fan created so this is not the tip to use when cleaning coverage is desired. The red tip does deliver the highest impact as it concentrates the pressure into the smallest area. Avoid damaging wood or other fragile surfaces. This is an ideal tool for cleaning under the deck of a lawnmower, removing caked on mud from equipment, cleaning stains from concrete, masonry, steel and aluminum even removing the grass from cracks in the sidewalk. |
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The yellow tip creates a 15 degree fan pattern. These pressure washer nozzles are referred to as chiseling tips. Held at a 45 degree angle you can use it like a scraper to remove peeling paint or mildew. It is also used for other tasks where breaking the bond is harder than average. Of your different pressure washer nozzles, you will find yourself using this one the most often when the task is tough. This is the only situation I know where you'll find that when the going gets tough the tough gets yellow. |
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The green tip produces a 25 degree fan pattern. This is a wash tip. These pressure washer nozzles are the ones to use when breaking the bond between the grime and substrate is reasonably easy. These can also be used for sweeping leaves or debris from flat surfaces or curbing. These pressure washer nozzles have the widest variety of applications as the fan degree allows for good impact pressure and cleaning coverage. |
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The white tip is the 40 degree fan tip. The wider dispersion of the impact pressure limits these pressure washer nozzles to rinsing and delicate washing. These are the tips to use for washing/rinsing glass or washing vehicles. These are great tips for wooden decks and all delicate substrates. |
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This is the last post is from a series of six on Everything You Ever Wanted To Know About Pressure Washing. Part One : What Is A Pressure Washer Part Two : How Does The High Pressure Washing Work Part Three : What Can A Pressure Washer Used For? Part Four : How To Use A Pressure Washer Part Five : What Are The Different Types Of Pressure Washer Part Six : Parts Of A Pressure Washer |
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[...] Parts Of A Pressure Washer | Ryobi Pressure Washer [...]
Lots of great content here on water pressure and washers. Thanks for writing this post, it will serve us handymen!
-Jack