At a glance
- Type
- Oil-free scroll
- Architecture
- Multi-element with sequenced loading
- Cooling
- Air-cooled
- Oil in compression
- None — oil-free by design
- Noise and vibration
- Very low — indoor installation
- Reserve capacity
- One element held in reserve
Overview
SCROLLPURE SS is a multi-element oil-free scroll compressor for low-flow, clean-air duty near people. A scroll element compresses air with two mating spirals and no injected liquid — no oil in the compression chamber or air path, no lubrication system, no separator. The category is quiet and compact, normally installed indoors beside the instruments and people it serves.
Model range
SCROLLPURE SS is the oil-free scroll family. Contact SIND for the current coverage.
Architecture
Multi-element oil-free scroll
- Cooling
- Air-cooled
- Oil in compression
- None
- Reserve element
- Yes — one element held in reserve
How to choose
By flow, pressure and duty cycle
- Start with
- Required FAD and pressure
- Then check
- Duty cycle and sound limit
- Before a quote
- Confirm the model row with SIND
When to specify scroll
Low flow, indoor, near people
- Flow
- Low — multi-element package
- Installation
- Indoor, beside occupied spaces
- Duty
- Standby, lead-lag, point-of-use
Technology
Technology Platform
ScrollPure SS uses oil-free scroll compression. A scroll element consists of two mating spirals — one fixed, one orbiting. As the orbiting scroll moves, it traps pockets of ambient air and progressively compresses them toward the centre of the spirals. No oil is injected into the compression chamber or air path. No lubrication system is required on the air side.
Multi-Element Architecture
ScrollPure SS packages multiple identical scroll elements in a single enclosure. The elements are loaded in sequence by the controller — as air demand increases, additional elements start; as demand decreases, elements stop. Capacity steps in whole-element increments.
Performance Boundaries
Scroll compression is the correct technology for low-flow, clean-air duty near people. It is not the answer above a few kilowatts of continuous duty — there a screw or variable-speed screw machine is the right choice. The boundaries are:
More technical detail
Technology Platform
The scroll compression process is continuous — there are no intake or discharge valves, and no reciprocating mass. This gives very low noise and vibration compared with piston compressors. The absence of oil in the compression chamber means the air is oil-free at the scroll element by design — not by downstream filtration.
Multi-Element Architecture
One element is held in reserve. If one element faults, the remaining elements carry part of the load and the faulty element is replaced. A single fault reduces capacity instead of stopping supply. This architecture provides inherent redundancy without the cost of a fully redundant parallel package.
Multi-element sequencing also improves part-load efficiency. Each element runs at its design point when loaded; there are no part-load penalties for individual elements. The package matches total air output to air demand by loading and unloading elements, rather than by modulating a single large compressor.
Performance Boundaries
- Flow per element — scroll elements are small, typically up to about 0.5 m³/min per element at low pressure. Multi-element packages scale up by adding elements, but the total package flow is still modest compared with screw compressors.
- Power per element — about 7.5 kW per element at low flow is the practical limit (category context, not a SIND rating). Above a few kW of continuous duty, choose a screw machine.
- Pressure — scroll compressors typically reach 8–10 bar(g) in standard configurations. Higher pressures are possible but reduce flow and efficiency.
- Duty cycle — scroll is ideal for standby, lead-lag or point-of-use duty beside a larger screw machine. Continuous full-load duty at high flow favours screw.
Key Design Decision: Why Scroll for Indoor, Near-People Duty?
Scroll compression is chosen for indoor, near-people installations because of three characteristics:
- Very low noise and vibration — continuous compression with no valves and no reciprocating mass gives sound pressure levels typically 10–20 dB(A) lower than equivalent piston compressors. The machine can be installed beside occupied spaces without acoustic enclosures.
- Oil-free by design — no oil in the compression chamber or air path means no oil carryover, no oil separator, no oil changes. The air is clean at the element outlet.
- Compact and quick start/stop — scroll elements are small and lightweight. The package is compact and can be installed at point of use, removing branch pipework and its leakage points. Quick start and stop allow standby or lead-lag duty beside a larger screw machine.
Maintenance and Service
Scroll compressors have few wearing parts compared with piston or screw compressors. There are no valves to service, no oil to change, no oil separator elements to replace. The main maintenance item is the scroll element itself — the tip seals wear over time and the element is replaced, not rebuilt. Element service interval depends on operating hours, discharge pressure and intake air quality.
Multi-element architecture simplifies maintenance: one element can be replaced while the others continue to run, so maintenance does not stop the air supply.
Selection Logic
ScrollPure SS selection is based on the following parameters:
Element count follows from the required flow. If the duty must not stop, specify a reserve element or two parallel packages.
- Required flow (m³/min): determined by the sum of all simultaneous air consumers plus margin.
- Required pressure (bar(g)): determined by the furthest endpoint’s minimum working pressure plus pipeline losses.
- Duty cycle: continuous full-load, standby/lead-lag, or point-of-use.
- Sound limit (dB(A)): scroll is chosen for low-noise indoor installations.
- Ambient conditions: indoor installation, clean and cool intake air required.
Selection & quote checklist
- Required flow (m³/min): determined by the sum of all simultaneous air consumers plus margin.
- Required pressure (bar(g)): determined by the furthest endpoint’s minimum working pressure plus pipeline losses.
- Duty cycle : continuous full-load, standby/lead-lag, or point-of-use.
- Sound limit (dB(A)): scroll is chosen for low-noise indoor installations.
- Ambient conditions : indoor installation, clean and cool intake air required.
FAQ
How do I select?
Fix flow at your inlet conditions, discharge pressure, duty cycle, ambient, sound limit and purity class. Element count follows from the required flow. If the duty must not stop, specify a reserve element or two parallel packages.
Is it oil-free?
No oil enters the compression chamber or air path. That is a design statement, not a purity certificate. Delivered air also depends on intake quality and downstream treatment.
How is it different from a piston or screw machine?
No reciprocating mass and no valves, so far less noise and vibration. No injected liquid, so no oil in the air path. Capacity grows by adding identical elements. Scroll is the correct choice for low-flow, indoor, near-people duty.
How large can scroll get?
About 7.5 kW per element at low flow is the practical limit (category context, not a SIND rating). Above a few kW of continuous duty, choose a screw machine.
What if one element fails?
The others carry part of the load and the element is replaced. If the duty must not stop, specify a reserve element or two parallel packages. Multi-element architecture provides inherent redundancy without the cost of a fully redundant parallel package.
More questions
Wet or dirty inlet air?
No. Liquid carry-over and abrasive contamination damage dry seals. Specify intake filtration and a clean, cool intake location. Scroll elements require clean, dry intake air for long service life.
Is it a medical device?
No medical-device claim is made. Any regulated medical-gas application is the buyer’s route. ScrollPure SS is an industrial compressor for instrument and process air.
Is 60 Hz available?
50 Hz standard. 60 Hz configuration on request.
Ownership & service
Energy, maintenance and service
Target Industries and Markets
ScrollPure SS is specified where low-flow, oil-free air is required near people:
- Laboratories and analytical instrument rooms — clean, dry, oil-free air for analytical instruments and laboratory air tools.
- Clinical and dental treatment rooms — instrument air for clinical procedures where oil-free air is required.
- Small clean rooms and packaging lines — in food and pharmaceutical work, where oil-free air is required at low flow.
- Electronics and small-parts assembly — clean, dry air for assembly and test operations.
- Instrument air for single machines and test benches — point-of-use air supply for individual machines or test stations.
- Low-noise indoor plant rooms — where the compressor is installed beside occupied spaces and low noise is required.
Energy and Total Cost of Ownership
Scroll compressors are not the most energy-efficient technology at high flow — screw compressors are more efficient above a few kW of continuous duty. The value of scroll lies in other aspects of total cost of ownership:
- Maintenance cost — few wearing parts, no oil changes, no oil separator elements. The main maintenance item is element replacement at long intervals. Multi-element architecture allows element replacement without stopping the air supply.
- Installation cost — compact, lightweight, low vibration. Can be installed at point of use without acoustic enclosures or dedicated compressor rooms. Removes branch pipework and its leakage points.
- Cost of oil contamination — in laboratories, clinics, clean rooms and electronics assembly, oil in the air stream causes instrument contamination, product rejection or surface defects. Oil-free compression removes this risk at the source.
- Redundancy value — multi-element architecture with reserve element provides inherent redundancy. A single fault reduces capacity instead of stopping supply.
Specifications vary by configuration; confirm with the datasheet. Dimensions and weights are indicative; request the installation drawing for the specific model before designing foundations or access routes.
