Choosing the Right Equipment
A Belt-Drive Machine utilizes a pulley system to create a speed reduction from the motor to the pump.(see attached) A heavy duty V-Belt drive PW should reduce the pump RPM by 50% so the pump is turning at half the speed of the engine and therefore, delivers longer life and less wear and tear on the pump. Again, don’t skimp on quality. Belt-drive is better because the pump lives a longer life, experiences less wear and tear, requires less service, and offers less downtime. Industrial quality belt-drive pumps such as Cat, AR and GP among a few other branded pumps are built to operate continuously. In addition, a belt-drive pump is essential if you are considering a draw tank set up as the decrease in RPM’s will be needed to adequately draw water from a tank.
A reliable and properly matched belt drive pump and power source from a proven manufacturer is critical. One should always consider a machine with an external bypass unloader. To add to the confusion not all belt-drives are created equally. Choose wisely… Some belt-drive PWs have only 2 V-belts. The best advice is to get a machine with at least 3 or 4 V-belts to ensure smooth power transmission and load distribution. One should also consider pump RPM as well. Some manufacturers offer belt-drive units that turn the pump at the same RPM as the motor RPM while the ratio should be a 2:1 ratio and not 1:1. A 1:1 ratio is no better than a direct-drive set up and actually misleads the consumer into thinking they have a legitimate V-Belt drive PW with reduced RPM pump. Remember, a belt-drive benefits are directly attributable to a slow speed pump (about 1450 RPM) versus the high speed engine RPM of 3400.
Poly-chain drive (cog-style) belt-drive systems are very reliable, have extreme durability and a smaller footprint. This proven design incorporates state of the art Kevlar-impregnated chain drive technology. The American made, Harley Davidson Motor Cycle manufacturer utilizes this type of drive to transfer power on their line of motorcycles. So it’s kind of cool and very reliable.
PSI vs GPM
GPM or gallons per minute describes the amount of water that the pump is producing in volume. For instance, an 8gpm machine will produce 8 gallons a minute. While the higher GPM translates to faster cleaning one has to take into consideration water source. If you intend on utilizing a spigot on a commercial or residential building you won’t want to consider a machine that has more than 4gpm. Whereas, if you’re wanting multi gun capability and greater speed a higher GPM such as 5.5 or 8 GPM can be obtained but you will also have to carry water in a tank to keep up with the pumps demand.
The other consideration then is PSI or Pressure per Square Inch. This describes the force that water is pushed thru an orifice. You might hear the term 3500psi or 4000psi. Really it’s the combination of GPM and PSI that give the machine its effectiveness. Some have referred to this as cleaning units. When a person multiplies the GPM and PSI together this number is arrived at and it can help you determine which unit has more cleaning units. For instance let’s consider two machines-4GPM X 4000psi = 16,000 CU’s
8GPM X 3000psi = 24,000 CU’s
Which unit will clean better? Example two has more cleaning units even though it has less psi.
When considering a machine the task at hand which you are cleaning is what will define what type of unit best meets your needs. For help in deciding what unit will best fit your needs, look to a reputable and professional dealer.
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