EQU - Water Stills Installation and Cleaning

Most water stills use mains water for single distillation and for cooling to condense the water vapour. Some of our stills allow for feeding in pre‐treated or tank water for distillation; water for cooling is also required.

Our two basic still designs are: the CASCADE, which produces 3L/h of single distilled water; the DELTA which produces 3 or 6L/h single distilled water or 3L/h double distilled water. The output is user selectable at any time by changing around some of the tubing.

• The CASCADE requires a standard 10 amp power outlet.
  
• The DELTA requires a 20 amp power outlet.

All water still models require a mains water tap with a ¾ inch garden hose type screw connection, to which a supplied filter connection is attached. This is for the cooling water on all models. On standard water stills this cooling water then passes into the boiler for distillation. The water supply must be available at mains pressure. A built‐in water flow regulator adjusts the water flowing into the still to the rate required for correct operation. The still has a valve to stop water flow. Hoses and fittings must be able to reliably withstand full mains pressure.

The Dual Feed models require a second water supply, fitted with a tap to regulate the flow to the still. The still is connected to this water supply using 10mm ID braided tubing, which is supplied. Water for dual feed systems is pre‐treated or has other desirable properties; it is trickle fed into the still to obtain very high purity water.

All models must have a drain or sink situated close to, and below, the water still. Unless the room containing the still is a 'wet room' with a floor drain, in which collecting vessels (carboys) can be on the floor, the still should be shelf‐ or wall‐mounted. The most common arrangement is to mount a strong shelf to hold the carboy above a sink, and the distillation unit needs to be a little higher than the top of the carboys. There are key holes in the rear of the distillation unit to allow hanging on the wall if required.

A reinforced water hose needs to be run to the two inlets, which are positioned near the bottom left of the still, using a Y or T piece to connect to both inlets. This would produce single distilled water only. Refer to instructions if the system is to be used to produce double distilled water or when using a dual feed system.

The waste water tubing from the stills must never be submerged in water in the sink or drain. Water flow to waste, and also water flow to the collecting vessels, must always be lower than the still. Any non‐pressurised tubing must be installed on a decline, if the tubing is level or runs uphill, back‐pressure will cause boilers and/or condensers to overflow.

It is convenient if the cooling (and treated feed) water supply valve is within reach, but not far from the still's inlets. Any container may be used as a reservoir to collect the distilled water. The most common are 2 large (50L carboys) plastic drums with a tap on the bottom. The stills are supplied with Reservoir Monitor Tubes, which must be placed through a hole in the top of the container to be used as a reservoir. The depth must be sufficient to allow the bottom of the Reservoir Monitor Tube to be located 150mm below the level at which the water in the reservoir is to stop rising. The top of the reservoir must also have a hole drilled for the distillate delivery tube, which is supplied, to pass through the top to allow distilled water to flow into the container. Another hole must be drilled to allow the container to breathe so that it is not airtight, otherwise the distilled water will not flow into the container. This hole should be loosely plugged with gauze or cotton wool to exclude dirt but still allow gaseous exchange.

The water stills have water supply monitors which, in the event of water supply failure, turn off the heating elements. The reservoir is monitored and when full, the stills are turned off, along with the water supply. If water is used from the reservoir, the still automatically restarts to maintain a full reservoir.

Thermal cut‐out devices are fitted to the boilers, which turn off the water supply and heating elements in the event of an over temperature situation being detected in the boilers.

CLEANING YOUR WATER STILL:

A weak acid such as a 10% solution of formic acid, or vinegar, or a commercial kettle de-scaler diluted as recommended by the manufacturer.

1. Turn off the power and remove the lid from the distiller boiling chamber.
2. Add 2 to 3 tablespoons of either Sulfamic Acid or white vinegar to the boiling chamber. Vinegar is milder than Sulfamic Acid to work with.
3. Agitate the solution by swirling the chamber for approximately 10 to 15 seconds.
4. Leave the solution sitting in the chamber overnight to allow it to continue cleaning on its own.
5. Empty the descaling solution from the boiling chamber the next morning.
6. Fill the chamber with clean water, swirling it around to rinse it out, then emptying it. Repeat to ensure all descaling residue has been removed.
7. Wipe the interior of the boiling chamber with a cloth to remove any last traces of solution residue then turn the power back on and watch to be sure the chamber fills and everything appears to be working properly.

FAQs

Does the still have a purity monitor?
Not built in. We sell water purity meters separately, however, if the feed water is of reasonable quality, double distilled water is always of very high purity.

Can the feed water temperature handle tap water?
Yes, but warm water requires a higher flow rate of cooling water.

Does the still have overflow prevention?
Yes.

Does the still have a stand‐by mode?
Yes.

Is the water suitable for PCR and DNA studies?
Yes.

Is the distilled water DNase and RNase free?
Yes.

Is the distilled water free of bacteria?
When freshly distilled, yes. We suggest high wall mounting of system, best above a sink, then water can accumulate in 50L carboys, one for single, and a second for double distilled water. Replace lids with thick wad of cotton wool and pass through cotton wool the tube that controls shut‐off when carboy is filled. Large carboys allow the system to run overnight.