Rotary Screw Air Compressors

How many CFM do these stationary compressors deliver?

At 25 HP, the Schulz SRP 4025E Dynamic lists 92 CFM and the SRP 3025 Compact lists 89 CFM. The stationary selection contains 31 Schulz and EL-AV models from 7.5 to 250 HP.

Here is the Schulz Dynamic fixed-speed quick reference, using the manufacturer's listed airflow:

• 7.5 HP: 25 CFM; 10 HP: 35 CFM.
• 15 HP: 51 CFM; 20 HP: 74 CFM.
• 25 HP: 92 CFM; 30 HP: 117 CFM.
• 40 HP: 150 CFM; 50 HP: 207 CFM.

Dynamic rows omit the airflow rating pressure, while Flex rows state it; compare the rating bases before using those figures to size your system. Start your shortlist with the tools and processes that run together, their working pressure and their combined air demand.

Should I choose fixed speed or variable speed?

The 10 HP SRP 4010 Dynamic lists 35 CFM, while the 10 HP SRP 4010 Flex lists 9–35 CFM @ 125 PSI. Dynamic is fixed speed; Flex is variable speed, also called VSD.

Fixed speed typically suits steady demand, while VSD is worth considering when your airflow demand changes through the day. For larger Flex sizes, these are the listed ranges:

• 25 HP: 23–92 CFM @ 125 PSI.
• 50 HP: 48–207 CFM @ 125 PSI.
• 100 HP: 133–385 CFM @ 125 PSI.
• 250 HP: 285–1,141 CFM @ 125 PSI.

EL-AV INV models are variable speed too. The ELAD15INV lists 15 HP and 11 – 56 CFM @ 116 PSI; the ELFD100INV lists 100 HP and 94 – 470 CFM @ 116 PSI. Keep your busy periods and lighter periods in view when choosing the control approach.

What receiver sizes, electrical supplies and sound figures are listed?

The SRP 4008 Dynamic has a 60 gallon ASME, horizontal receiver, while the SRP 3025 Compact has an 80 gallon ASME, horizontal receiver. The SRP 4010 Dynamic lists a 120 gallon ASME, horizontal receiver.

The SRP 4050E Dynamic and Flex entries are base mounted with no tank. That makes receiver configuration a separate part of the selection, alongside airflow. A receiver typically buffers short demand peaks; sustained work still needs sufficient compressor output.

Schulz stationary sound figures span 68–91 dB(A), and EL-AV figures span 64–72 dB(A), as listed. EL-AV entries show 460V · 3-phase. Several smaller Schulz entries show 230V / 460V, with phase options identified in the table.

How do the Atlas Copco portables compare?

The XAS 110 KD8 lists 95 CFM, and the XAS 400-150 PACE JD lists 400 – 440 CFM. The 8 portable listings also include electric E-Air models: H185 lists 130 – 192 CFM and H250 lists 178 – 233 CFM.

Engine-driven portables and stationary electric machines serve different power and installation requirements. Portable does not mean engine driven across this group. For pressure-specific reference, the X-Air 185-100 cold-weather model lists 189 CFM @ 100 PSI.

Portable sound figures span 61–82.6 dB(A) as listed; measurement methods and airflow rating conditions differ, so treat these as a shortlist rather than a normalized ranking.

Common questions

How many CFM does a 25 HP rotary screw deliver?

The SRP 3025 Compact lists 89 CFM, the SRP 4025E Dynamic lists 92 CFM, and the SRP 4025E Flex lists 23–92 CFM @ 125 PSI.

Which listed rotary screw has a 60 gallon tank?

Schulz SRP 3008 Compact, SRP 3015 Compact-II and SRP 4008 Dynamic each list a 60 gallon ASME, horizontal receiver.

Are the EL-AV INV compressors variable speed?

Yes. The listed INV range runs from ELAD15INV at 15 HP to ELFD100INV at 100 HP.

What does the SRP 4030E Flex list for airflow?

It lists 25–113 CFM @ 125 PSI, with 30 HP and a 120 gallon ASME, horizontal receiver.

Can you help size a rotary screw compressor?

Yes. Contact us for a free sizing consultation with your working pressure, delivered airflow requirement, electrical supply and operating pattern.