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

Product Overview

The ROSS Controls Mid-Size Series Filter and Lubricator is a modular air preparation unit designed for pneumatic systems requiring simultaneous particulate filtration and oil-mist lubrication at mid-range flow rates up to 100 scfm (2,832 l/min). Compatible with port sizes from 1/4 to 1/2 inch, the series is built for modular mounting, enabling direct integration into ROSS FRL assemblies that include separate filter, regulator, and lubricator components interconnected without intermediate piping.

The filter section employs a 5-micron rated polyethylene element as standard, removing particulate contamination and coalescing water aerosols before they can reach downstream actuators, valves, and tooling. The condensate management system offers automatic or manual drain configurations, with the automatic drain option providing zero-maintenance condensate removal during continuous production operations.

Lubrication is delivered through a sight-feed mechanism with an external, tamper-resistant adjustment. The sight dome provides visual confirmation of oil delivery rate during operation, giving maintenance personnel real-time feedback on lubricator performance without removing the unit from service. Oil is drawn from a 4-oz (120-ml) reservoir bowl and introduced into the airstream as a controllable oil mist.

Bowl construction choices include polycarbonate plastic with a zinc shatterguard for standard operating conditions, and zinc metal bowl for elevated temperature and pressure applications. Both bowl options use the same head and cartridge components, enabling bowl material upgrades in the field without changing the head assembly. The modular design supports integration with ROSS FRL systems using standard clamp and port block accessories.

Key Engineering Features

• Modular Mounting Design - Allows direct combination with other ROSS FRL modules, including individual filters, regulators, and lubricators, into a single connected assembly without intermediate pipe fittings or hoses.
• Sight-Feed Lubricator - Visual oil-delivery confirmation through the sight dome allows operators to verify lubricator performance at a glance during normal operation, without removing the unit from service.
• External Tamper-Resistant Oil Adjustment - External adjustment knob can be removed to prevent unauthorized changes to lubrication rate, with a locking key option available for high-security production environments.
• 5-Micron Filtration - Standard 5-micron polyethylene element removes particulate contamination and coalesces liquid water to protect downstream pneumatic components from abrasive wear and corrosion.
• Polycarbonate Bowl with Zinc Shatterguard - High-strength polycarbonate bowl provides liquid level visibility while the zinc shatterguard limits fragment projection in the event of bowl breakage, improving personnel safety.
• Zinc Metal Bowl Option - Alternative zinc bowl withstands higher pressures and temperatures beyond the polycarbonate limit, extending the operating envelope to 200 psig (14 bar) and 175 F (80 C).
• Automatic or Manual Drain Filter - Automatic drain expels condensate continuously without operator action. Manual drain provides positive control over condensate discharge timing in sensitive production areas.
• 4-Oz Lubricant Reservoir - 120-ml bowl capacity provides adequate service interval between oil refills for typical industrial duty cycles at mid-range flow applications.
• Replaceable Cartridge Architecture - All working components, including the sight-feed mechanism and filter element, are housed in a cartridge designed for quick replacement, minimizing maintenance time during scheduled service.
• Port Size Flexibility - Available in 1/4, 3/8, and 1/2 inch port sizes within a single product family, allowing the same head and bowl assembly to be reconfigured for different circuit sizes.

Technical Specifications

General Specifications

Temperature Ratings

Temperature limits are determined by bowl material. Polycarbonate bowls are limited to 125 F (52 C). Zinc metal bowls extend operation to 175 F (80 C) for both ambient and media conditions.

Important: Do not expose polycarbonate bowls to solvents, ketones, esters, chlorinated hydrocarbons, or other chemicals that cause stress cracking. Use zinc metal bowls in chemical exposure environments.

Certifications & Compliance

Typical Applications & Industries

General Industrial Automation and Manufacturing

• Pneumatic cylinder supply conditioning on conveyor systems, indexing tables, and transfer mechanisms where 1/4 to 1/2 inch port sizes and flows up to 100 scfm match standard cylinder bore and speed requirements.
• Solenoid valve manifold air supply preparation, delivering filtered and lubricated air to multi-valve manifolds controlling actuator banks on automated assembly lines.
• Air-actuated gripper and tooling supply conditioning on industrial robots and gantries, where the sight-feed lubricator provides immediate visual confirmation of lubrication delivery during commissioning and production.
• Rotary actuator and air motor supply preparation on material handling equipment, where consistent lubrication is critical to maintaining torque output and extending service life of vane-type air motors.
• Pneumatic press brake and stamping machine cylinder supply, providing filtered and lubricated air to the high-force cylinders that require clean supply for consistent seal performance and repeatable stroke.

Packaging Machinery

• Case erecting and carton forming machine pneumatic supply, where medium-bore cylinders with 3/8 or 1/2 inch port connections require filtered and lubricated air for reliable high-speed cycling.
• Vertical form-fill-seal (VFFS) and horizontal form-fill-seal (HFFS) machine cylinder supply conditioning, protecting jaw actuation and film drive cylinders from contamination and dry running.
• Palletizer and depalletizer row pusher and layer separator cylinder supply, delivering filtered and lubricated air to the large-bore cylinders responsible for row alignment and layer separation.
• Label applicator and print-and-apply system cylinder supply, where consistent lubrication ensures repeatable label placement by maintaining uniform cylinder stroke speed across production shifts.

Automotive Manufacturing and Welding

• Spot welding gun pneumatic cylinder supply on resistance welding equipment in body-in-white production, where filtered and lubricated air protects the welding gun throat cylinder seals from contamination generated in the weld environment.
• Assembly torque tool supply conditioning for pneumatic nut runners and screwdrivers used in powertrain and chassis assembly, where sight-feed lubrication confirmation reduces under-lubrication risk on high-torque tools.
• Transfer line fixture clamping cylinder supply preparation on engine and transmission machining lines, where reliable filtration and lubrication of fixture cylinders is critical to maintaining part-to-part positioning repeatability.
• Paint line conveyance cylinder supply conditioning, where zinc metal bowls are specified for elevated ambient temperature areas near cure ovens operating above 125 F (52 C).

Food and Beverage Processing

• Capping machine chuck cylinder and pilfer-proof ring application cylinder supply, where consistent lubrication is required for repeatable capping torque and secure cap engagement at production rates.
• Filling machine piston and cylinder supply conditioning on high-speed liquid filling lines, providing filtered and lubricated air to filling valve actuators and piston pump drives.
• Conveyance diverter and gate cylinder supply on product sorting and accumulation systems, where the 100 scfm flow capacity supports simultaneous operation of multiple medium-bore cylinders.
• Packaging line reject station cylinder supply, where reliable air preparation ensures consistent actuation of product reject flaps, paddles, and diverter gates without flow-related inconsistency.

Textile and Printing Industry

• Loom gripper and rapier actuator supply conditioning on weaving machines, where wick-feed or sight-feed lubrication of the rapier drive cylinders extends seal life in high-cycle weaving applications.
• Web press cylinder supply preparation on sheet-fed and web offset printing presses, providing filtered and lubricated air to plate clamping, blanket tensioning, and delivery cylinder circuits.
• Fabric cutting machine pneumatic knife and clamp cylinder supply, where the modular mounting format integrates the filter-lubricator directly into the machine base air distribution manifold.
• Textile finishing machine pneumatic padder and mangle cylinder supply conditioning, where 3/8 or 1/2 inch port sizes deliver adequate flow for large-bore padding cylinders in continuous production.

Plastics and Rubber Processing

• Injection molding machine clamp cylinder supply conditioning, providing filtered and lubricated air to the toggle-clamp pneumatic assist cylinders on medium-tonnage injection molding presses.
• Blow molding machine preform stretch rod and mold opening cylinder supply preparation, where consistent lubrication at flows up to 100 scfm supports the high-speed cycling characteristic of rotary blow molding.
• Extrusion line product cutter and puller cylinder supply conditioning on continuous extrusion operations, where zinc metal bowls are selected for elevated temperature zones near the extruder barrel.

Ordering and Model Number Configuration

The Mid-Size Series Filter and Lubricator is ordered by model number encoding the port size, drain type, and bowl material. G (BSPP) threads are indicated by a 'C' prefix. Contact ROSS Controls for modular assembly configurations and custom port block arrangements.

Standard thread is NPTF. For G (BSPP) threads, prefix the model number with 'C' (example: C5M11B2101).

Polycarbonate bowl models are rated to 150 psig (10 bar) and 125 F (52 C). Zinc metal bowl models extend to 200 psig (14 bar) and 175 F (80 C).

Automatic drain models require minimum 15 psig (1 bar) inlet pressure. Manual drain models operate from 0 psig.

Minimum airflow for lubricator operation is 2 scfm (0.94 l/s). Systems with flows consistently below this threshold should be evaluated for alternative lubrication methods.

For modular assemblies combining the series filter-lubricator with regulators or lockout valves, specify module connecting clamps and port blocks from the ROSS FRL accessories catalog.

Replacement filter elements: standard 5-micron polyethylene (936K77). No sintered bronze options are listed as standard for the Mid-Size Series; contact ROSS Controls for alternate element availability.

Accessories

Replacement Filter Elements

Replacement filter elements for the Mid-Size Series. The 5-micron polyethylene element (936K77) is the standard replacement for scheduled maintenance.

Modular Assembly Hardware

Module connecting clamps and brackets are used to assemble the series filter-lubricator with other ROSS FRL components into a modular unit. Panel mounting requires a 1-9/16 inch (40 mm) hole.

End Ports and Port Blocks

Male and female end ports and extra port blocks allow custom inlet/outlet configurations and multi-unit modular assemblies. Contact ROSS Controls for specific end port and port block model numbers matched to the Mid-Size platform.

Related Products & Accessories

• 135 Miniature Filter and Lubricator Series - Compact inline filter-lubricator for 1/8 and 1/4 inch ports with wick-feed lubrication and flows up to 19 scfm, for space-constrained installations. https://www.rosscontrols.com/en/series/135-miniature-series
• 137 Full-Size Filter and Lubricator Series - Modular filter-lubricator for 1/4 to 3/4 inch ports with flow capacity up to 138 scfm and choice of wick-feed or sight-feed lubrication. https://www.rosscontrols.com/en/series/137-full-size-series
• 138 High-Capacity Filter and Lubricator Series - Inline filter-lubricator for 3/4 and 1 inch ports delivering up to 270 scfm for high-demand industrial applications. https://www.rosscontrols.com/en/series/138-high-capacity
• ROSS Mid-Size FRL Combination Unit - Complete filter, regulator, and lubricator combination in the Mid-Size platform, adding pressure regulation to the series filter-lubricator functionality. https://www.rosscontrols.com/en/series/144-md4-series
• ROSS Pressure Regulators (Mid-Size) - Modular pressure regulators in the Mid-Size format for integration with the series in complete FRL assemblies. https://www.rosscontrols.com/en/documents
• L-O-X Lockout Valves - Safe energy isolation lockout valves compatible with modular ROSS FRL assemblies for OSHA-compliant lockout/tagout. https://www.rosscontrols.com/en/series/1287-lockout-valves-15-series

Frequently Asked Questions (FAQ)

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

A: The Mid-Size Series delivers up to 100 scfm (2,832 l/min) through 1/4, 3/8, and 1/2 inch port sizes. Flow capacity is primarily limited by port size selection, with larger port sizes approaching the maximum rated capacity.

Q: What is a sight-feed lubricator and how does it work?

A: A sight-feed lubricator introduces oil into the airstream by drawing it from the bowl reservoir through an adjustable needle valve and past a sight dome, where the operator can visually count oil drops per minute. This provides direct, real-time confirmation of lubrication delivery during operation. The oil is then atomized into a fine mist that is carried downstream with the compressed air to lubricate pneumatic components.

Q: What is the minimum flow required for the lubricator to operate?

A: The minimum operating flow for the Mid-Size Series sight-feed lubricator is 2 scfm (0.94 l/s). At flow rates below this threshold, the lubricator may not generate sufficient pressure differential across the oil metering system to deliver oil consistently. Systems with sustained flows below 2 scfm should use the 135 Miniature Series wick-feed lubricator or low-flow wick-feed models.

Q: What is the difference between polycarbonate with shatterguard and zinc metal bowl?

A: The polycarbonate bowl with zinc shatterguard provides liquid level visibility for monitoring oil and condensate levels, with the shatterguard limiting fragment projection in the event of bowl damage. It is rated to 150 psig (10 bar) and 125 F (52 C). The zinc metal bowl provides higher pressure capability to 200 psig (14 bar) and higher temperature tolerance to 175 F (80 C), at the cost of liquid level visibility.

Q: Can the series be mounted modularly with other ROSS FRL components?

A: Yes. The modular mounting design of the series is specifically engineered for direct connection to other ROSS FRL components using module connecting clamps and port blocks, without intermediate pipe fittings. This allows the creation of compact multi-function FRL assemblies sharing a common air path.

Q: Is the sight-feed lubricator adjustment tamper-resistant?

A: Yes. The external oil adjustment knob can be removed after setting the desired delivery rate, preventing unauthorized changes to lubrication settings. An optional locking key configuration is available for additional security in regulated production environments. Contact ROSS Controls for locking key options.

Q: What inlet pressure is required for automatic drain operation?

A: Automatic drain models require a minimum inlet pressure of 15 psig (1 bar) to actuate the float-operated drain valve. At pressures below 15 psig, the automatic drain will not function correctly and condensate will accumulate in the bowl. Specify the manual drain configuration for systems operating below 15 psig.

Q: What type of oil should be used with the series?

A: Use petroleum-based lubricating oil with an aniline point between 180 F and 220 F (82 C to 104 C), ISO VG 32 viscosity or lighter. Avoid phosphate esters, synthetic esters incompatible with nitrile seals, and halogenated solvents. Do not use silicone oils, as these can contaminate pneumatic components and clog seals over time.

Q: How is the filtration element replaced?

A: To replace the filter element, depressurize the system and remove the bowl. Unscrew the filter element (model 936K77) from the head assembly, discard the used element, and install a new element, ensuring the O-ring seal is properly seated. Reinstall the bowl and return the system to service. Consult the ROSS Controls installation instructions for the complete procedure.

Q: What port thread standards are available?

A: The Mid-Size Series is available in NPTF (standard) and G (BSPP) thread configurations. G thread models are ordered by adding the prefix 'C' to the model number (example: C5M11B2101 for a 1/4" BSPP automatic drain polycarbonate bowl unit).

Q: What is the bowl capacity and expected refill interval?

A: The Series lubricator bowl holds 4 oz (120 ml) of oil. Refill interval depends on operating flow rate, lubrication rate setting, and system duty cycle. At a typical setting of 1 drop per 5 scfm at 100 psig, a 4-oz bowl may provide 8 to 24 hours of operation at moderate flow rates. Monitor the oil level through the polycarbonate bowl or by checking at scheduled maintenance intervals with metal bowls.

Q: Can a regulator be added to the series to create a complete FRL?

A: Yes. The modular design of the series allows the addition of a ROSS Mid-Size modular regulator to create a complete filter-regulator-lubricator (FRL) assembly using module connecting clamps. Alternatively, ROSS offers pre-configured Mid-Size FRL combination units that include filter, regulator, and lubricator in a single assembly. Contact ROSS Controls for configuration options.

Q: What is the expected service life of the series filter element?

A: Service life depends on air supply contamination levels and operating hours. Inspect the filter element at each scheduled maintenance interval and replace when pressure drop across the filter exceeds approximately 10 psig (0.7 bar) at system flow rate, or at least annually. Maintain the upstream air compressor and aftercooler properly to minimize condensate and particulate loading on the filter element.

Installation & Maintenance Guidelines

• Mount the Mid-Size Series with the bowl oriented downward to ensure condensate collects at the drain valve and oil remains accessible to the sight-feed mechanism throughout the service cycle.
• For modular assemblies, align the internal port passages of all connected modules before torquing the clamp hardware. Misalignment creates internal leakage paths and reduces system pressure.
• Flow direction must match the arrow on the unit body. Reverse installation prevents automatic drain operation and reduces filter element life.
• Provide a minimum of 6 inches (150 mm) clearance below the bowl for element replacement and manual drain access without disconnecting the unit from the system.
• Use PTFE thread tape or approved thread sealant on NPTF connections. Tighten to hand-tight plus 1.5 turns; do not over-torque as this may crack the head casting.
• For automatic drain units, verify minimum 15 psig (1 bar) supply pressure before startup. Confirm drain function by observing condensate discharge during initial system pressurization.
• Adjust the oil delivery rate by observing the oil drop frequency through the sight dome. Set the adjustment to deliver the rate recommended by the downstream component manufacturer, typically expressed as drops per minute or drops per scfm.
• Remove the adjustment knob after setting the desired lubrication rate to prevent unauthorized changes in production environments.
• Flush the supply line before connection to remove pipe scale, thread compound, and installation debris that would load the filter element prematurely.
• Use only petroleum-based ISO VG 32 or lighter lubricating oil. Do not use synthetic oils incompatible with nitrile seals or any fluid that could damage polycarbonate bowl material.

Warranty & Global Support

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

Technical support is available through ROSS Controls global offices: 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 data sheets, and authorized distributor locations.

Spare parts including replacement filter elements (936K77), sight dome assemblies, and seal kits are available through ROSS Controls and authorized distributors.

Download Catalog: https://www.rosscontrols.com/en/documents/196?filename=ROSS_FRL_Combination_Units_Filter_Lubricator.pdf