Mid-Size Series Port Sizes 1/4" to 1/2"; Flow to 100 scfm (2832 l/min)

Product Overview

The ROSS Controls Mid-Size Filter/Regulator integrates air filtration and pressure regulation in a single modular-mount assembly for pneumatic systems with port sizes from 1/4" to 1/2" and flow requirements to 100 scfm (2832 l/min). The modular mounting design allows the series to be assembled into multi-unit FRL trains alongside ROSS lubricators and individual filters, enabling a complete air preparation system configured to application requirements.

A piston-type regulator provides precise outlet pressure control from 0 to 100 psig (7 bar), maintaining stable downstream pressure as supply pressure and flow demand vary. The 4-oz (120 ml) bowl capacity is sized for the higher condensate volumes associated with mid-size flow rates and 1/4" through 1/2" port pneumatic circuits, reducing the frequency of required maintenance drain intervals.

Bowl material choices include a polycarbonate plastic bowl with steel shatterguard for visual condensate monitoring in standard environments, and a zinc bowl with clear sight glass for installations requiring higher pressure capability or greater chemical resistance. Both automatic drain and manual drain configurations are available, accommodating both unattended and supervised maintenance strategies.

The Series is designed for a wide range of general industrial pneumatic applications including machine tool supply lines, assembly automation, material handling equipment, and production machinery where mid-size port connections and moderate flow capacity represent the majority of point-of-use requirements.

Key Engineering Features

• Modular Mounting Design - Supports assembly into multi-unit FRL trains with ROSS lubricators, individual filters, and downstream components, allowing a complete air preparation system to be built from standardized modular elements.
• Piston-Type Regulator - Delivers precise, stable outlet pressure control with high flow capacity relative to body size, maintaining regulated pressure as inlet pressure and flow demand vary across the operating range.
• Polycarbonate Bowl with Steel Shatterguard - Transparent polycarbonate bowl allows direct visual inspection of condensate level and bowl condition; steel shatterguard contains fragments in the unlikely event of bowl failure in high-pressure applications.
• Zinc Bowl with Clear Sight Glass - Metal zinc bowl provides higher pressure capability (up to 200 psig) and broader chemical compatibility than polycarbonate, with a clear nylon sight glass for condensate level monitoring.
• Automatic or Manual Drain - Automatic drain removes condensate continuously without operator intervention; manual drain provides controlled condensate removal for periodic maintenance or contamination monitoring schedules.
• 4-oz (120 ml) Bowl Capacity - Larger bowl volume than miniature-series units reduces condensate drain frequency for mid-size flow circuits and extended production shift operations.
• NPT and G (BSPP) Thread Options - Standard NPT threads for North American installations and G (BSPP) threads for international markets. G thread models ordered by adding a C prefix to the model number.
• Outlet Pressure to 100 psig (7 bar) - Piston regulator covers the full operating pressure range of standard industrial pneumatic actuators and control devices connected at 1/4" through 1/2" ports.
• 5-Micron Polyethylene Filter Element - Standard 5-micron filtration removes particulate contamination from compressed air, protecting downstream actuators, valves, and instruments from accelerated wear and failure.
• Multiple Replacement Element Options - 5-micron polyethylene (standard) and sintered bronze elements in 5-, 20-, and 40-micron ratings provide filtration options matched to contamination level and element durability requirements.

Technical Specifications

General Specifications

Certifications & Compliance

Typical Applications & Industries

General Industrial Automation

• Main air preparation supply for pneumatic actuators, rotary actuators, and cylinders in general industrial machinery where 1/4" to 1/2" port connections represent the standard connection size and flow requirements fall within the 100 scfm capacity range.
• Assembly line air preparation stations serving multiple downstream pneumatic tools and actuators from a single modular FRL assembly, with modular construction enabling lubricator add-on when tool lubrication is required.
• Material handling equipment including pneumatic lifters, transfer units, and indexing tables requiring clean, regulated air at the point of use to ensure consistent cycle times and actuator force output.
• Robotic workcell air supply where the modular FRL assembly is mounted within the cell enclosure, providing local air preparation close to the robot arm and end-of-arm tooling actuators.

Machine Tool and Metalworking

• CNC machining center air preparation where regulated, filtered air supplies spindle cooling air nozzles, workholding pneumatics, tool change actuators, and coolant blow-off circuits from a common modular air preparation assembly.
• Stamping and forming press pneumatic control circuits where clean, regulated air ensures consistent actuator stroke and force characteristics across high-volume production runs.
• Grinding machine air gauging and workholding circuits requiring precise pressure regulation at 1/4" to 1/2" port sizes to maintain dimensional accuracy throughout the gauging cycle.

Packaging and Material Handling

• Primary air preparation for packaging machinery including cartoners, case packers, and filling lines where modular FRL assembly provides clean regulated air to multiple pneumatic actuators in a single compact installation.
• Conveyor system pneumatic controls including divert gates, stop cylinders, and pneumatic pusher units on sortation lines where the 100 scfm flow capacity accommodates simultaneous actuation of multiple devices.
• Palletizing and depalletizing equipment where reliable air quality and pressure regulation directly affect gripper and vacuum cup performance across full production shifts.

Food and Beverage Processing

• Air preparation for pneumatic actuators in food processing equipment where the polycarbonate bowl with shatterguard provides visual condensate monitoring and the zinc body resists the cleaning chemicals used in food production environments.
• Bottling and filling line pneumatics requiring consistent pressure regulation to maintain fill accuracy and seal quality across high-speed production runs.
• Compressed air supply to pneumatic valves and diverters in beverage processing lines where pressure regulation ensures accurate actuation and the filter element protects valve seats and seals from particulate-induced wear.

Ordering and Model Number Configuration

The Series model number encodes the bowl type, drain type, and port size. Select the appropriate model number from the table above, or contact ROSS Controls for custom configurations.

For G (BSPP) threads, add the prefix C to the model number (e.g., C5321B2052 for 1/4 G port, polycarbonate bowl, automatic drain).

Polycarbonate bowl models begin with 5321; zinc (metal) bowl models begin with 5322.

Automatic drain variants end in 52 or 51; manual drain variants end in 62 or 61.

Contact ROSS Controls at (800) 438-7677 for configurations outside the standard model list or for assistance selecting the appropriate replacement filter element.

When ordering modular configurations combining the series with lubricators or additional filter units, contact ROSS Controls for complete assembly model numbers and modular interface hardware.

Accessories

Replacement Filter Elements

Standard 5-micron polyethylene element (936K77) and optional sintered bronze elements in 5-micron, 20-micron, and 40-micron ratings are available for the Mid-Size Series.

Modular Add-On Components

The Series supports modular assembly with ROSS lubricators and individual filter units. Modular interface hardware allows multiple components to be connected without additional piping, creating a complete inline FRL train. Contact ROSS Controls for modular assembly configurations and hardware specifications.

Related Products & Accessories

• 131 Miniature Series Integrated Filter/Regulator - Inline-mount integrated FR for port sizes 1/8" and 1/4" with flow to 19 scfm, compact form factor. https://www.rosscontrols.com/en/series/131-miniature-series
• 133 Full-Size Series Integrated Filter/Regulator - Modular-mount integrated FR for port sizes 1/4" to 3/4" with flow to 138 scfm, piston-type regulator. https://www.rosscontrols.com/en/series/133-full-size-series
• 134 High-Capacity Series Integrated Filter/Regulator - Inline-mount integrated FR for port sizes 3/4" to 1" with flow to 270 scfm for high-demand applications. https://www.rosscontrols.com/en/series/134-high-capacity-series
• 65 Mid-Size Series Integrated Filter/Regulator - Modular integrated FR with tamper-resistant knob, self-relieving or non-relieving piston regulator, port sizes 1/4" to 1/2". https://www.rosscontrols.com/en/series/65-mid-size-series
• MD3 Series Integrated Filter/Regulator - Modular integrated FR with diaphragm regulator and optional L-O-X lockout valve, port sizes 1/4" to 1/2". https://www.rosscontrols.com/en/series/66-md3-series

Frequently Asked Questions (FAQ)

Q: What is the maximum flow capacity of the Mid-Size Series?

A: The Mid-Size Series is rated for flow to 100 scfm (2832 l/min). This capacity is suitable for the majority of industrial pneumatic actuator and tool supply circuits using 1/4" to 1/2" port connections. For higher flow requirements, the 133 Full-Size Series (to 138 scfm) or 134 High-Capacity Series (to 270 scfm) should be considered.

Q: What port sizes are available?

A: The Series is available in 1/4 inch, 3/8 inch, and 1/2 inch port sizes with either NPT or G (BSPP) threads. For G thread models, add the prefix C to the standard NPT model number.

Q: What is the maximum outlet pressure?

A: The piston-type regulator provides outlet pressure adjustable up to 100 psig (7 bar). This range covers the operating pressure requirements of most standard industrial pneumatic cylinders, actuators, and pneumatic tools.

Q: What is the difference between the polycarbonate and zinc bowl options?

A: The polycarbonate bowl with steel shatterguard provides visual condensate inspection and is rated to 150 psig maximum operating pressure. The zinc bowl with clear sight glass provides higher pressure capability to 200 psig, greater chemical resistance, and an elevated upper temperature limit of 175 degrees F (80 degrees C) versus 125 degrees F (52 degrees C) for the polycarbonate bowl.

Q: How does the modular mounting work?

A: The Series modular design allows multiple units to be bolted together side by side using modular interface hardware, creating a complete FRL assembly without additional pipe connections between components. Contact ROSS Controls for modular mounting hardware and assembly specifications.

Q: What drain type should I select?

A: Automatic drain is recommended for unattended systems, high-humidity environments, or installations where frequent condensate accumulation is expected. Manual drain provides positive operator control and is appropriate for supervised installations or applications where condensate composition is monitored as part of air quality management.

Q: What filter element is standard?

A: The standard filter element is a 5-micron rated polyethylene element (model 936K77). Optional sintered bronze elements are available in 5-micron (R-KA60F-03E5), 20-micron (R-KA60F-03E4), and 40-micron (R-KA60F-03E3) ratings. Sintered bronze elements are more durable and can be cleaned and reused in service.

Q: Is the regulator self-relieving?

A: Yes. The piston-type regulator in the series is self-relieving, allowing excess downstream pressure to bleed back through the regulator when the set point is reduced, eliminating the need for manual downstream venting during pressure adjustments.

Q: Can the series be panel mounted?

A: Yes. The Series supports panel mounting using a 1-9/16 inch (40 mm) diameter hole. The unit installs through the panel with the bowl accessible from the front for routine maintenance.

Q: What are the temperature limits for each bowl type?

A: Polycarbonate bowl models are rated from 40 to 125 degrees F (4 to 52 degrees C) for both ambient and media temperature. Zinc bowl models extend the upper temperature limit to 175 degrees F (80 degrees C), making them suitable for warmer industrial environments.

Q: What is the bowl capacity?

A: The Series uses a 4-oz (120 ml) bowl, providing greater condensate storage than miniature-series units and reducing maintenance drain frequency for mid-size flow circuit installations.

Q: Are G (BSPP) thread models available?

A: Yes. G (BSPP) thread models are available for all port sizes. To order a G thread model, add the prefix C to the corresponding NPT model number. For example, C5321B2052 is the 1/4 G, polycarbonate bowl, automatic drain variant.

Q: What is the warranty?

A: ROSS Controls provides a one-year warranty on all products, covering defects in material and workmanship from the date of purchase. Contact ROSS Controls USA at (800) 438-7677 for warranty claims or technical support.

Installation & Maintenance Guidelines

• Mount with the bowl oriented downward to allow condensate to collect by gravity for proper drain operation.
• Install the unit in the supply line with adequate clearance below the bowl for removal during element replacement and condensate drain maintenance.
• Do not exceed 150 psig with polycarbonate bowl models or 200 psig with zinc bowl models.
• Do not expose polycarbonate bowls to solvents or chemicals that attack polycarbonate; use zinc bowl models in chemically aggressive environments.
• For automatic drain models, verify that the drain outlet has a clear path for condensate discharge and is not obstructed or back-pressurized.
• For manual drain models, establish a scheduled drain interval based on air system humidity levels and observed condensate accumulation rates.
• Use thread sealant or thread tape on NPT connections; apply sparingly to prevent sealant from entering the air circuit.
• Replace the filter element when pressure drop across the unit increases noticeably or on a scheduled maintenance interval.
• After installation, gradually increase inlet pressure while observing the unit for leaks before bringing the system to full operating pressure.
• Verify that outlet pressure is set within the operating range of downstream components before energizing pneumatic circuits.

Warranty & Global Support

ROSS Controls provides a one-year warranty on all products, covering defects in material and workmanship from the date of purchase.

Global technical support is available through ROSS offices in the USA (headquarters in Ferndale, Michigan), Canada, Brazil, Germany, France, United Kingdom, India, China, and Japan.

Contact ROSS Controls USA at (800) 438-7677 or visit rosscontrols.com for product configuration, technical support, and distributor locator services.

For complete technical data, dimensional drawings, and product configurator access, visit the ROSS Controls Mid-Size Series product page or contact ROSS Controls directly.

Download Catalog: https://www.rosscontrols.com/en/series/132-mid-size-series