The cleaning power of a high pressure jet comes from effective pressure AND water flow rate.
In Singapore, a professional high pressure jet must have an effective pressure of at least 100 – 110 Bar (about 1600 psi) of pressure. This effective pressure is different from the maximum pressure the pump can achieve. The accompanying flow rate must then be at least 11 L/min.
Some high pressure jets advertise a pressure of 130 / 150 Bar and 8 L/min flowrate, which generally will not clean as well as a pressure of 100 Bar at 11 L/min. This is because much more cleaning is done with the extra 3 L/min of water flow rate.
It is important to note that high pressure jet can damage certain types of delicate surfaces. Never spray the high pressure water jet directly on other people, as injury and damage can result.
A high pressure jet cannot draw more water from the pipe to which it is connected to. Water supply must be adequate because water deprivation can lead to premature damage to the pump elements.