Michael
New member
Paul B., contact ANY of the pump manufacturers and speak with their engineers.
When I use the terms 'In General' and 'On Average' it is merely because I am not one of them but a well schooled pressure washer manufacturer.
Water is an incompressible fluid, but the action of the piston/plunger moving to fill within the cylinder creates a vacuum. The 'strength' of this vacuum is relative to the swept volume of the cylinder; period.
There are a finite number of piston sizes available to fit the vast percentage of pressure washer pumps. This is both a design and packaging decision. Pressure washers manufacturers very in details like component composition, seal design and material spcifications.
Therefore in order to maintain set flow in a positive displacement manner you have two options: a whole lot of small bits in a given time or fewer larger bits in the same time. The swept volume of a 3450 RPM pump is a fraction of the swept volume of a 1450 RPM pump given the same output. Exactly like the diesel engine versus gasoline engine analogy I used previously.
Seals are only present to keep the water and oil from mixing and from allowing the water to leak beyond the area of the piston/plunger. They resist water incursion only. Unlike an engine where they have a profound effect on compression.
FYI, pumps do NOT produce pressure. Never have and never will. The pressure is created by the presence of a specific sized orifice restricting flow. Pumps are rated for their resistance to pressure based on the weakest component.
No manufacturer of pressure washers or pumps would recommend using the unloader to vary volume or pressure. It is a primary safety device and the rings and seals would be subject to unnecessary wear leading to premature failure. Every good manufacturer suggests using different sized tips to vary pressure. Volume is dependent on RPM because of the positive displacement nature of the pump.
ALL pumps are rated to produce a certain flow at a given RPM and a resistance to pressure. ALL pumps should be force fed with a supply at least 1 GPM over demand and a head pressure of at least 15 PSI and usually no greater than 90 PSI. However, high RPM pumps do not have enough vacuum to draw water from a supply tank because they are incapable of self-priming. Therefore they do nto draw soap very well downstream at hose lengths greater than 150'. Low RPM pumps are better able to self-prime and therefore draw soap better, they suck better than high speed pumps.
When I use the terms 'In General' and 'On Average' it is merely because I am not one of them but a well schooled pressure washer manufacturer.
Water is an incompressible fluid, but the action of the piston/plunger moving to fill within the cylinder creates a vacuum. The 'strength' of this vacuum is relative to the swept volume of the cylinder; period.
There are a finite number of piston sizes available to fit the vast percentage of pressure washer pumps. This is both a design and packaging decision. Pressure washers manufacturers very in details like component composition, seal design and material spcifications.
Therefore in order to maintain set flow in a positive displacement manner you have two options: a whole lot of small bits in a given time or fewer larger bits in the same time. The swept volume of a 3450 RPM pump is a fraction of the swept volume of a 1450 RPM pump given the same output. Exactly like the diesel engine versus gasoline engine analogy I used previously.
Seals are only present to keep the water and oil from mixing and from allowing the water to leak beyond the area of the piston/plunger. They resist water incursion only. Unlike an engine where they have a profound effect on compression.
FYI, pumps do NOT produce pressure. Never have and never will. The pressure is created by the presence of a specific sized orifice restricting flow. Pumps are rated for their resistance to pressure based on the weakest component.
No manufacturer of pressure washers or pumps would recommend using the unloader to vary volume or pressure. It is a primary safety device and the rings and seals would be subject to unnecessary wear leading to premature failure. Every good manufacturer suggests using different sized tips to vary pressure. Volume is dependent on RPM because of the positive displacement nature of the pump.
ALL pumps are rated to produce a certain flow at a given RPM and a resistance to pressure. ALL pumps should be force fed with a supply at least 1 GPM over demand and a head pressure of at least 15 PSI and usually no greater than 90 PSI. However, high RPM pumps do not have enough vacuum to draw water from a supply tank because they are incapable of self-priming. Therefore they do nto draw soap very well downstream at hose lengths greater than 150'. Low RPM pumps are better able to self-prime and therefore draw soap better, they suck better than high speed pumps.
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