Miniature Series Port Sizes 1/8" & 1/4"; Flow to 24 scfm (680 l/min)

Product Overview

The ROSS Controls Miniature Series is a family of compact inline integrated filter/regulators designed for port sizes 1/8 inch and 1/4 inch (NPT or G/BSPP threads) with maximum flow capacity of 23 scfm (651 l/min). The Miniature Series is optimized for inline (pipeline) mounting, making it well-suited for applications where space is limited and a direct in-line installation is preferred over a modular manifold approach.

The Miniature Series features an aluminum body construction, which provides a more robust housing than acetal-bodied units while maintaining compact overall dimensions. Filter/regulator units combine particulate filtration and pressure regulation in a single assembly with an integrated pressure gauge for continuous downstream pressure monitoring. Bowl options include high-strength polycarbonate for visual liquid level observation or aluminum for higher temperature and pressure applications.

Filtration configurations include 5-micron standard polyethylene elements, with 20-micron and 40-micron sintered bronze elements as options. The integrated piston-type regulator provides stable outlet pressure with a self-relieving function (non-relieving available as an option). Drain options are automatic internal drain or manual drain. The adjusting knob is removable for tamper-resistance in applications where pressure setpoint security is required.

For engineers specifying inline air conditioning in instrumentation panels, small machine tools, pneumatic control cabinets, or any application requiring clean, regulated air at 1/8 or 1/4 port sizes without the overhead of a modular manifold system, the Miniature Series delivers a straightforward, catalog-standard solution with well-established replacement elements and broad accessory availability.

Key Engineering Features

• Filter and Regulator in a Single Inline Assembly - Combines 5-micron particulate filtration and precision pressure regulation in one compact inline unit, eliminating separate filter and regulator bodies and the plumbing connection between them.
• Aluminum Body Construction - Die-cast aluminum body provides structural rigidity and improved corrosion resistance compared to acetal alternatives. Suitable for demanding industrial environments where physical durability is required.
• Inline Mounting Configuration - Designed for direct in-line pipeline installation with NPT or G (BSPP) threaded inlet and outlet ports. Installs directly in the air supply line without brackets, manifolds, or mounting plates.
• High-Strength Polycarbonate or Aluminum Bowl - Polycarbonate bowl provides visual liquid accumulation monitoring. Aluminum bowl option extends operating temperature to 150 deg F (66 deg C) and maximum inlet pressure to 200 psig (14 bar) for severe-duty environments.
• Automatic or Manual Drain - Automatic drain continuously purges collected condensate and liquids, eliminating manual drain tasks in production environments. Manual drain provides operator-controlled purging for applications where timed or monitored drain events are preferred.
• 5-, 20-, and 40-Micron Filtration Options - Standard 5-micron polyethylene element removes fine particulates. Optional 20-micron and 40-micron sintered bronze elements available for coarser-cut prefiltration stages or where sintered bronze element material is preferred.
• Piston-Type Self-Relieving Regulator - Piston regulator provides stable, accurate downstream pressure under varying flow demands. Self-relieving function automatically vents downstream overpressure when inlet supply drops or setpoint is reduced.
• Non-Relieving Regulator Option - Non-relieving variant eliminates the exhaust vent path for applications using compressed gases where downstream venting is not acceptable.
• Removable Adjustment Knob for Tamper Resistance - The regulator knob can be removed after setting outlet pressure, preventing unauthorized or accidental pressure changes in production or safety-sensitive applications.
• Integrated Pressure Gauge Standard - Pressure gauge is factory-installed on filter/regulator units for immediate visual pressure monitoring without additional gauge tees or fittings.
• Compatible Replacement Elements Shared with Bantam Series - The Miniature Series uses the same 933K77 (5-micron) replacement element as the Bantam Series, simplifying spare parts stocking across both series.

Technical Specifications

General Specifications

Temperature Ratings

Temperature ratings depend on bowl material. Polycarbonate bowl has a lower upper temperature limit than the aluminum (metal) bowl option.

Important: Do not expose polycarbonate bowls to solvents, ketones, chlorinated hydrocarbons, or other incompatible chemicals. When chemical exposure is possible or ambient temperature exceeds 125 F, select the aluminum bowl option.

Flow Performance Data

Flow performance is for the 5-micron standard polyethylene element at 100 psig inlet pressure. Element loading and inlet pressure below 100 psig will reduce maximum flow.

Certifications & Compliance

Typical Applications & Industries

Pneumatic Control Panels and Instrumentation

• Inline air conditioning for pneumatic instrumentation panels, control enclosures, and field instrument supply headers where limited panel space favors compact inline units over modular manifold assemblies.
• Positioner supply air conditioning for pneumatic valve positioners and I/P transducers where 5-micron filtered, regulated air at 20 to 60 psig is required at the instrument supply port.
• Compressed air supply to pressure transmitters, differential pressure cells, and process analyzers where contaminated or unregulated supply air would damage sensitive instrument internals.
• Pneumatic control circuit conditioning in process control applications including flow controllers, level controllers, and pressure controllers using pneumatic signal transmission.

Machine Tools and Small Automation

• Inline air preparation for machining center coolant system pneumatics, tool holder air purge, and spindle air seal circuits at 1/4-inch port size.
• Pneumatic power supply conditioning for small robot pneumatic grippers, end effectors, and tool changers where inline mounting simplifies plumbing in confined robot wrist assemblies.
• Air preparation for small pneumatic cylinders in packaging machinery, assembly automation, and conveying systems where direct inline installation avoids modular manifold hardware.
• Compressed air supply for air bearing spindles, air gauging probes, and precision measurement equipment where particulate and pressure stability are critical to measurement accuracy.

Electronics and Semiconductor Manufacturing

• Clean air supply for pneumatic wafer handling, mask aligner pneumatics, and die bonding systems where 5-micron filtration reduces particulate contamination risk on process surfaces.
• Inline air preparation for PCB assembly pneumatics including component placement, dispensing systems, and pneumatic inspection fixtures requiring stable, clean supply air.
• Air supply conditioning for electrostatic discharge (ESD) ionizer blower systems where contaminated supply air degrades ionizer electrode performance.
• Nitrogen or clean dry air (CDA) supply conditioning in electronics manufacturing where inline units can be used with non-reactive specialty gases in addition to compressed air.

Medical Device and Pharmaceutical Equipment

• Air preparation for laboratory automation systems, robotic sample handlers, and liquid dispensing robots in clinical laboratory and pharmaceutical manufacturing environments.
• Compressed air conditioning for pneumatic packaging systems in pharmaceutical filling lines where compact inline units fit within restricted machine frame geometries.
• Inline air supply for medical device assembly pneumatics requiring clean, regulated air at consistent pressure for pneumatic press operations, leak testing, and functional testing.
• Dental equipment air supply conditioning and laboratory air preparation systems requiring compact, reliable filter/regulator units at 1/4-inch port size.

Ordering and Model Number Configuration

The ROSS Miniature Series uses a structured 10-digit model number system distinguishing port size, bowl type, and drain type. Inline models use 4-digit body codes. Prefix C selects G (BSPP) threads.

For G (BSPP) threads, prefix the model number with C (e.g., C5021B1010 for 1/8-inch G, auto drain, polycarbonate bowl).

The Miniature Series is inline mount only; for modular mount applications with 1/8 or 1/4 ports, select the Bantam Series instead.

Non-relieving regulator option available; consult ROSS Controls for the applicable model number designation.

Replacement filter element 933K77 is shared with the Bantam Series, simplifying spare parts inventory across both series.

Panel mounting requires a 1-3/16 inch (30 mm) hole.

Accessories

Replacement Filter Elements

ROSS replacement filter elements for the Miniature Series are shared with the Bantam Series, simplifying spare parts management.

Related Products & Accessories

• Bantam Series Modular Integrated Filter/Regulators - Modular-mount version for 1/8 and 1/4 port sizes, suitable for building FRL manifold stations with adjacent components. https://www.rosscontrols.com/en/series/62-bantam-series
• Mid-Size Series Air Preparation Filters - Modular and inline filters for 1/4 to 1/2 port sizes with flow to 75 scfm for higher-flow pneumatic circuits. https://www.rosscontrols.com/en/series/76-mid-size-series
• MD3 Series Air Preparation Filters - High-flow modular filters for 1/4 to 1/2 port sizes with flow to 92 scfm, diaphragm-type regulator, and L-O-X lockout integration. https://www.rosscontrols.com/en/series/72-md3-series
• L-O-X Lockout Valves - OSHA-compliant pneumatic lockout valves for energy isolation during maintenance on pneumatic systems. https://www.rosscontrols.com/en/series/1287-lockout-valves-15-series
• FRL Lubricators (Miniature / Bantam) - Miniature and Bantam Series lubricator units for use in modular FRL assemblies where downstream air tools or actuators require lubrication. https://www.rosscontrols.com/en/series/62-bantam-series

Frequently Asked Questions (FAQ)

Q: What distinguishes the Miniature Series from the Bantam Series?

A: The Miniature Series is designed for inline (pipeline) mounting as a standalone unit, while the Bantam Series is configured for modular assembly where multiple FRL components share a single inlet and outlet through a port kit or manifold. Both cover 1/8 and 1/4 port sizes, but the Miniature Series uses an aluminum body compared to the Bantam's acetal body. Select the Miniature Series for direct inline installation; select the Bantam for modular FRL station construction.

Q: What is the maximum inlet pressure for Miniature Series units?

A: Polycarbonate bowl models have a maximum inlet pressure of 150 psig (10 bar). Aluminum bowl models are rated to 200 psig (14 bar). These ratings apply to both automatic drain and manual drain configurations.

Q: What outlet pressure range does the regulator support?

A: The integrated piston-type regulator is adjustable from near zero to a maximum of 100 psig (7 bar). The standard configuration is self-relieving; a non-relieving option is available for applications where downstream exhaust is not permitted.

Q: Can the Miniature Series be ordered with BSPP (metric) threads?

A: Yes. Add the prefix C to the model number to specify G (BSPP) threads. For example, C5021B1010 is the 1/8-inch G thread, auto drain, polycarbonate bowl model.

Q: What filtration level does the standard element provide?

A: The standard filter element is rated at 5 microns and is made of polyethylene (part number 933K77). Optional sintered bronze elements are available in 5-micron, 20-micron, and 40-micron ratings for applications requiring different filtration cut points or where sintered bronze material is preferred.

Q: What are the temperature limits for the Miniature Series?

A: Polycarbonate bowl units are rated from 40 to 125 F (4 to 52 C). Aluminum bowl units extend the upper temperature rating to 150 F (66 C). Both ambient and media (compressed air) temperatures must remain within the rated range.

Q: Is an automatic drain or manual drain recommended?

A: Automatic drain is recommended for most production applications where maintaining drain management without operator intervention is preferred. Manual drain is appropriate for applications with reliable maintenance access, low condensate generation, or where controlled drain timing is required.

Q: What is the flow capacity of the Miniature Series?

A: Maximum flow is 23 scfm (651 l/min) through the 5-micron standard element at 100 psig inlet pressure. This is slightly lower than the 30 scfm of the Bantam Series, reflecting the compact inline body geometry. For flows above 23 scfm at 1/4-inch port size, the Bantam Series or a step up to the Mid-Size Series is recommended.

Q: What replacement element should I stock for Miniature Series units?

A: The standard 5-micron polyethylene replacement element is 933K77, which is the same element used in the Bantam Series. This shared element number simplifies spare parts procurement and stocking for facilities operating both series.

Q: Can the regulator knob be locked to prevent unauthorized adjustment?

A: The adjustment knob is removable for tamper resistance. After setting the desired outlet pressure, remove the knob and store it separately to prevent unauthorized pressure changes. Reinstall the knob only when pressure adjustment is needed.

Q: How is the Miniature Series panel-mounted?

A: Panel mounting requires a 1-3/16 inch (30 mm) diameter hole. The unit includes mounting hardware for panel installation, allowing installation on control panel doors or machine guards with the gauge face and adjustment knob accessible from the front.

Q: What body material is used in the Miniature Series?

A: The Miniature Series uses an aluminum body, providing better structural rigidity and corrosion resistance compared to acetal-body alternatives like the Bantam Series. Aluminum construction makes the Miniature Series suitable for environments where physical durability and resistance to mild chemical exposure are required.

Installation & Maintenance Guidelines

• Mount inline with flow direction matching the arrow or inlet/outlet markings on the unit body. Reverse installation will not damage the unit but will prevent proper filter and drain function.
• Vertical mounting with bowl pointing down is preferred for optimal condensate drainage, particularly for automatic drain models.
• Install a shutoff valve upstream of the unit to allow element replacement and service without full system depressurization.
• Ensure upstream air is free of gross contamination. In applications with scale, rust, or other heavy debris, install a coarse strainer upstream of the Miniature Series filter/regulator.
• Set regulator pressure before connecting downstream equipment by slowly increasing inlet supply and adjusting the regulator knob. Turn clockwise to increase outlet pressure.
• For manual drain models, drain collected condensate before the liquid level rises to the bottom of the filter element. Liquid carryover through the element will degrade downstream equipment.
• Replace the 5-micron filter element when differential pressure across the filter reaches 10 psig (0.7 bar), or at scheduled preventive maintenance intervals.
• Do not exceed maximum inlet pressure for the bowl type selected: 150 psig for polycarbonate, 200 psig for aluminum. Pressure cycling near maximum ratings accelerates bowl material fatigue.
• Verify all threaded port connections are made wrench-tight but not over-torqued. Over-torquing NPT fittings can crack the aluminum body ports.
• After initial installation, pressurize gradually and inspect all connections for leaks before placing equipment into service.

Warranty & Global Support

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

Global technical support is available through ROSS Controls 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 selection assistance, technical support, and distributor locator services.

For complete dimensional drawings, flow curves, and catalog data, visit the ROSS Controls Miniature Series product page at rosscontrols.com or download the ROSS FRL catalog.

Download Catalog: https://www.rosscontrols.com/en/series/64-miniature-series