Single-Stage Water Still

What is the Single-Stage Water Still?

A single-stage water still boils and condenses feed water once to remove non-volatile ions and pyrogens. It is the standard unit for routine reagent water and autoclave feed in many general laboratories.

Overview

The single-stage water still heats water in a boiler and condenses the vapor in a water-cooled or air-cooled condenser. Output ranges from 2 to 20 liters per hour, with conductivity of about 1 to 5 microsiemens per centimeter and low pyrogen content. A baffle above the boiling surface reduces droplet carry-over, which is the main path by which salts contaminate the distillate. Level control maintains a safe water level, and a low-level cutout protects the heating element. The boiler is made from borosilicate glass or stainless steel, and the condenser from glass, stainless or copper. Hard feed water causes scale, so softening is recommended, and periodic descaling with acid keeps output and quality stable. These units are simple and reliable and are used for general reagent preparation and sterilizer feed.

How does it work?

A distillation unit heats feed water to boiling in a boiler, and the steam rises through a column or baffle that separates entrained droplets carrying dissolved salts. The vapor then condenses on a cooled surface and is collected as distillate. Non-volatile ions, particles and pyrogens remain in the boiler, which is drained periodically, while volatile substances such as ammonia, carbon dioxide and some organics may carry over unless a baffle or a second stage traps them. Single-stage stills give conductivity of about 1 to 5 microsiemens per centimeter, and double-stage units reach lower values by distilling the distillate again. Typical components are the boiler with heating elements and level control, the condenser with cooling water or air, the baffle, and conductivity monitoring. Scale from hard water forms on the elements, so descaling is routine maintenance.

What are the key features?

• Single boil and condensation stage
• Output of 2–20 L/h
• Conductivity of about 1–5 µS/cm
• Baffle to reduce droplet carry-over
• Level control and low-level cutout
• Borosilicate glass or stainless steel boiler

What are the technical specifications?

A typical single-stage water still configuration offers output of 2–20 L/h, conductivity of 1–5 µS/cm, heater power of 2–12 kW, cooling of Water or air cooled, boiler material of Borosilicate glass or stainless steel and condenser material of Glass, stainless steel or copper. Values are indicative of the product class; the exact figures for each configuration are confirmed on the quotation and the calibration documents supplied with the instrument.

Which applications is it used for?

The Single-Stage Water Still is used in reagent water preparation, autoclave feed, microbiology media, glassware final rinse and standard methods requiring distilled water. Across the wider Distillation Units class, laboratories also deploy it for reagent and buffer preparation, autoclave and sterilizer feed and microbiology media preparation.

Which standards and certifications apply?

Relevant standards and methods include ISO 3696, CLSI GP40, USP <645>, IEC 61010-1 and ISO 9001. Certification candidates for this model are CE, ISO 9001 manufacturing and RoHS; each is to be confirmed for the specific configuration before shipment, and certificates are supplied only where they have been issued.

Feed the still with softened or pretreated water to slow scale formation, and descale on a regular schedule with a suitable acid. Do not let the boiler run dry; keep level controls and low-level cutouts in working order. Ensure adequate cooling water flow and temperature, because poor cooling reduces output and may allow vapor to escape. Drain the boiler concentrate regularly to prevent salt buildup, and never let it concentrate beyond the design limit. Clean the condenser and collection vessel to avoid re-contamination, and cover stored distillate. Follow IEC 61010-1 for electrical safety and local rules for hot water and steam. Record conductivity, output and descaling dates so quality and maintenance stay under control.

How do I select the right Single-Stage Water Still?

Choose a single-stage still for general reagent and sterilizer water where moderate purity is adequate. For lower conductivity and pyrogen content, choose a double-stage or quartz unit. In the RFQ, state output, feed hardness and cooling availability.

How does it compare with other Distillation Units variants?

Begin with the required water quality and volume. Single-stage stills suit general reagent preparation and autoclave feed, while double-stage or quartz stills are chosen when very low conductivity and low pyrogen content are needed. Match output to daily demand, considering that a still runs continuously and needs cooling water unless it is air-cooled. Check the material of the boiler and condenser, since borosilicate glass, quartz and stainless steel differ in contamination and durability. Hard feed water increases scaling and maintenance, so consider softening or reverse osmosis pretreatment. Look for automatic level control, over-temperature protection and conductivity monitoring, and confirm whether the design allows easy descaling. Finally, compare energy and cooling water consumption, because distillation has the highest operating cost of the common purification methods.