I advise you to get a pump if you want to maintain shot quality and without any knowledge of your food permit regulations, how are you going to supply running hot & cold water ?. A pump is not expensive and heavy duty marine pumps are built in a compact size and can be very reliable. Some are designed to run on low voltage, so you may need to have a appliance to convert the power (again, buy quality not price). Check out marine suppliers in your area - go and talk to them as most have considerable knowledge on the topic. Whilst it's true you can run without positive inlet pressure, it's not recommended to do so long-term - these are the words from a person who has been importing hundreds of commercial machines into Australia for around 20 years - likely to be a more reliable source of anecdotal truths than any forum or people who may have done it a few times (yeah - she'll be right mate). If an external pump fails, you go into the backup plan bypass mode until resolved - no big deal and something that should only take a few minutes if you are prepared. The machine you are referring to - and I have many of them installed in cafes - there is a momentary "dead zone" that occurs when the pump cuts in during a shot - it is the same design on many other comparable machines and not isolated to Expobars. By relying upon the creation of pressure to suck up water from a neutral zone every time the pump kicks in, you are in effect increasing the dead zone by almost double or triple factor, depending upon the efficiency of your equipment and the plumbing setup (length of hoses, number of bends, fittings, filters, etc.). The other issue to resolve is how are you going to filter the water into your equipment - beforehand when you fill your tanks ? If you run a pump, you can setup the machine the same as a cafe with a filter on the inlet. Many of the mobile coffee units we supply experience a lot of problems with water quality when they attend events.
