The level of pressure loss (∆ P) in a vacuum system has a direct impact on vacuum equipment sizing and is one of the key factors in overall system performance and efficiency. For our purposes, ∆ P is defined as the difference in pressure level between the inlet of the vacuum pipe to the inlet of the vacuum pump (or system).

Unlike compressed air, there is a limit of how much we can overcome the effect of ∆ P in a vacuum system. Depending on the operating pressure requirement, even a ∆ P as low as 1 Torr (i.e. 1 mm) can still greatly impact the size of the pump(s) or system.

To help quantify ∆ P, and to take the guess work out of equipment and pipe sizing, Busch has developed our Pipe Loss Program v. 1.04. With the program we are able to assist you in representing the calculated level of ∆ P in your system based on factors like pressure, capacity, pipe size/length/type, gas stream components, temperatures, etc.

In every vacuum system, the pipe the vacuum equipment is connected to plays a direct role in determining system performance and efficiency. Often, the impact of inadequate pipe diameters is overlooked or misunderstod, resulting in loss of pressure and capacity where it is needed most - the operating points.

As an example, let's consider the ∆ P results generated by our program for a vacuum system that is capable of delivering 500 ACFM @ 125 Torr (25" Hgv) at the pump inlet, handling air @ 70F. The piping system it is connected to has a total equivalent length of 250' and is constructed from carbon steel:

As you can see in this example, selecting a larger diameter pipe results in lower ∆ P and higher delivered capacity at the pipe inlet. While no formal, published standard exists for how much ∆ P is acceptable in a vacuum system, a good rule of thumb is to limit it to less than 10% of the base pressure (in absolute terms).

Note: Not all applications benefit from using larger diameter pipe - consult with a Busch Application Engineer prior to making any piping decisions or changes.

To learn more about pressure loss in your system, or for assistance with your application, call to speak to one of our highly qualified Application Engineers at 1-800-USA-PUMP, or, fill out and submit a copy of our Engineering Inquiry form.