Vertical Autoclave Buying Guide: Sizes, Construction, Controls and Installation
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A vertical autoclave is a top-loading steam sterilizer: you lower loads into a cylindrical chamber, lock the lid, and the unit heats water to produce pressurized steam. It is a common choice for microbiology labs, teaching labs, clinics, and small production sites that need more capacity than a benchtop unit without the cost and footprint of a horizontal, front-loading sterilizer. This guide explains how to choose the right chamber size, what to look for in construction and controls, and what you need to plan for in utilities and installation before the crate arrives.
When a vertical autoclave makes sense
Vertical units suit labs that sterilize media bottles, glassware, instrument trays, and autoclavable waste bags in batches. Because they load from the top, they use floor space efficiently and can hold tall items such as media bottles and waste bags. The trade-offs are that heavy loads must be lifted in and out, and there is no pass-through option. If your loads are small and infrequent, a portable benchtop autoclave may be enough; SciMed also offers a 21 L portable autoclave and a 24 L electric portable autoclave for lighter workloads.
Choosing a chamber size
Vertical autoclave chambers are usually described by inside diameter × depth in inches. SciMed's vertical autoclave is offered in sizes from 10 × 18 to 22 × 30. Approximate capacities listed on the product page are:
| Chamber (in) | Approx. capacity | Typical fit (from product page) | Price |
|---|---|---|---|
| 10 × 18 | ~23 L | Small lab, dental or veterinary clinic; instruments only | $4,400 |
| 12 × 20 | ~37 L | Single-lab microbiology, tissue culture bottles | $5,000 |
| 14 × 22 | ~55 L | Mid-size microbiology lab, small production | $5,500 |
| 16 × 24 | ~79 L | Clinical lab, larger veterinary practice | $6,000 |
| 18 × 24 | ~100 L | Tissue culture facility, pilot production | $6,200 |
| 22 × 30 | ~180 L | Central sterilization, large teaching lab | $6,500 |
| 22 × 30 A | ~180 L | As 22 × 30, with full stainless construction, range up to 134 °C, PID controller with timer and alarm buzzer, and lower water cut-off | $6,900 |
How to size for your workload
- Size for your peak day, not your average. If your busiest load does not fit, you will run extra cycles, and each cycle can take well over an hour including heat-up and cool-down.
- Measure your tallest item. Media bottles, flasks, and waste bags need head room. Check the depth against the tallest item plus a basket or rack.
- Measure your widest item. Wrapped instrument trays must fit inside the diameter, with space for steam to circulate.
- Do not overpack. Steam needs to reach every surface. A chamber packed tight may not sterilize the center of the load.
- Consider liquid volumes separately. Large volumes of media need longer exposure and slow exhaust, which extends cycle time.
Construction: what to check
Chamber and walls
Stainless steel chambers resist corrosion from steam and are easier to clean. The SciMed unit uses triple-wall SS 304 construction: an inner chamber, a middle wall, and an outer wall, with argon-arc welded joints described as ground and polished. Ask any supplier which grade of stainless is used for the chamber and whether the outer body is stainless or painted steel, since this affects cleaning and long-term appearance.
Lid and gasket
The lid is the main pressure boundary you interact with every cycle. Look at how it locks and how easily it lifts. The SciMed unit uses a machined SS 304 lid with radial locking, a molded silicone gasket, and a foot-pedal lift assist. Gaskets wear over time, so ask whether replacements are available and how they are fitted.
Pressure testing
Pressure vessels are hydrostatically tested at the factory above their working pressure. Ask the supplier what test pressure was used, which code or standard (if any) the vessel is built and certified to, and whether a test record is supplied with your specific unit. Do not assume; ask for the paperwork, because some facilities and insurers require it.
Controls and safety devices
A standard steam cycle is 121 °C at about 15 psi. Some applications call for 134 °C. Check what the controller lets you set and what it displays.
- Temperature control: a PID controller with a digital readout gives more consistent cycles than a simple pressure switch. A built-in timer and alarm let operators walk away and return when the cycle ends.
- Pressure gauge: an analog dial gauge is a useful independent check on chamber pressure.
- Low-water cut-off: prevents the heater from running dry, which can damage the element and chamber.
- Safety valve: a spring-loaded valve releases pressure if it exceeds a set limit.
- Vacuum breaker: prevents a vacuum forming as the chamber cools.
- Exhaust and drain valves: needed for controlled steam release and for draining water between uses.
Whichever unit you buy, verify each cycle with chemical indicators and periodically with biological indicators. The controller display tells you what the sensor sees; indicators tell you what the load experienced.
Utilities and installation
- Electrical supply: the SciMed vertical autoclave's standard configuration is 220 V, 50 Hz, and the 22 × 30 A version requires 220 V single-phase. Confirm your available circuit with a facilities electrician before ordering, and discuss 110 V options with the supplier if needed.
- Water quality: the product page recommends distilled or RO/DI water. Tap water leaves mineral scale on heating elements and chamber walls.
- Floor and weight: these are floor-standing units. Crated weight is listed at roughly 180–250 kg depending on size, so plan for a lift-gate delivery and a clear path to the install location.
- Ventilation: steam release and hot surfaces add heat and humidity to the room. Allow clearance around the unit and avoid placing it beside temperature-sensitive equipment such as incubators.
- Drainage: plan where condensate and drained water will go.
Heavy equipment ships in 7 business days.
Specification summary: SciMed vertical autoclave
| Specification | Value (from product page) |
|---|---|
| Type | Vertical, top-loading, cylindrical steam autoclave |
| Construction | Triple-wall SS 304 |
| Chamber sizes | 10 × 18, 12 × 20, 14 × 22, 16 × 24, 18 × 24, 22 × 30, 22 × 30 A (inches) |
| Sterilizing condition | 121 °C at 15 psi (1.2 kgf/cm²) |
| Operating pressure range | 15–22 psi adjustable |
| High-temperature option | Up to 134 °C (22 × 30 A only) |
| Lid | Machined SS 304, radial locking, pedal-lift assist |
| Gasket | Jointless molded silicone rubber |
| Controls | Auto set at 15 psi / 121 °C; 22 × 30 A adds PID controller with timer and alarm buzzer |
| Safety devices | Low-water indicator and cut-off, automatic pressure switch, steam release valve, water outlet valve, spring-loaded safety valve, vacuum breaker, miniature circuit breaker |
| Power | 220 V, 50 Hz |
| Price range | $4,400 to $6,900 depending on size |
Questions to ask any supplier
- What is the hydrostatic test pressure, and which pressure-vessel code or standard does the unit carry? Will I receive the test record for my serial number?
- What stainless steel grade is used for the chamber, lid, and outer body?
- What voltage, phase, and current does my chosen size require?
- How long is a typical cycle, from cold start to safe opening, for a liquid load versus a dry load?
- Which safety devices are fitted, and how are they tested or replaced?
- Are gaskets, heating elements, and valves available as spare parts, and what is the lead time?
- If I need validation documentation for my facility, what can you provide?
- What is the crated weight and size, and what does delivery require?
Frequently asked questions
What size vertical autoclave do I need?
Choose the chamber that fits your largest regular load with room for steam to circulate. Measure your tallest bottles and widest trays, and compare against the diameter and depth.
Is 121 °C enough for most lab sterilization?
121 °C at about 15 psi is the standard steam cycle for many lab media, glassware, and instrument loads. Exposure time depends on load type and size. Some protocols specify 134 °C; confirm what your protocols require.
Can I use tap water?
Distilled or RO/DI water is recommended. Tap water deposits minerals that shorten element life and leave scale in the chamber.
Can a vertical autoclave handle biohazard waste?
Vertical autoclaves are commonly used for autoclavable lab waste bags. Check your institution's biosafety requirements for the waste category, and validate your waste cycle with indicators.
What should not go in an autoclave?
Flammable or volatile chemicals, heat-sensitive plastics, electronics, and dry powders that need dry heat should not be steam sterilized.
Request a quote
See all sizes and options for the SciMed Vertical Autoclave Sterilizer. For a formal quote or to send a purchase order, email sales@scimedstore.com or call (669) 265-9353. Include the chamber size, your available voltage, and a short description of your typical loads.