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 is a modular Filter Regulator Lubricator (FRL) combination product line designed for 1/4" to 1/2" port size compressed air systems. The Mid-Size Series delivers combined filtration, pressure regulation, and lubrication with flow capacity up to 100 scfm (2832 l/min), addressing the air preparation requirements of the majority of industrial pneumatic systems and machine-mounted air treatment applications.

The modular mounting design of the Mid-Size Series allows individual filter, regulator, and lubricator units to be interconnected side-by-side on a common manifold bracket, forming a compact inline FRL station that can be assembled to meet the exact air treatment stages required by the application. Each component can also be installed as a standalone unit where only a single air preparation function is needed.

The filter component is available with a polycarbonate plastic bowl with shatterguard protection or a zinc metal bowl, accommodating different environmental conditions. Internal automatic drain and manual drain options are available to match condensate volume and maintenance preferences. The piston-type regulator provides stable output pressure regulation with self-relieving or non-relieving function. A sight-feed lubricator delivers visible, adjustable oil delivery into the air stream, allowing the operator to confirm and control lubrication rate during operation.

The integral pressure gauge on the regulator unit provides continuous output pressure monitoring at the air preparation station. The Mid-Size Series is the standard selection for main machine air preparation in 1/4" through 1/2" pneumatic systems across general industrial, automotive, packaging, and food and beverage manufacturing applications.

Key Engineering Features

• Modular FRL Combination System - Individual filter, regulator, and lubricator units interconnect on a common bracket to form a compact modular FRL station, allowing users to assemble only the air treatment stages required without excess components.
• High Flow Capacity for Mid-Size Port Range - Delivers up to 100 scfm (2832 l/min), providing adequate flow capacity for the majority of 1/4" to 1/2" port size pneumatic circuits in machine and process automation applications.
• Modular Mounting Design - Components mount side-by-side on standard modular brackets for organized, space-efficient installation that simplifies maintenance access to each component independently.
• Polycarbonate Bowl with Shatterguard or Zinc Bowl - Polycarbonate bowl with zinc shatterguard combines visual condensate level monitoring with mechanical bowl protection; zinc metal bowl provides a fully sealed metal enclosure for harsh environments.
• Internal Automatic or Manual Drain Filter - Internal automatic drain continuously expels accumulated condensate; manual drain provides operator-controlled drainage during maintenance intervals for lower condensate volume applications.
• Piston-Type Regulator - Piston-type pressure regulator provides stable regulated output pressure with consistent performance across the flow demand range of 1/4" to 1/2" pneumatic systems.
• Self-Relieving or Non-Relieving Regulator - Self-relieving function vents downstream pressure to atmosphere when set point is reduced; non-relieving option retains downstream pressure for restricted-vent circuits.
• Sight-Feed Lubricator - Sight-feed design provides visible confirmation of oil delivery rate through a window or sight tube, allowing operators to observe and adjust the lubrication rate during system operation.
• Integral Pressure Gauge - Pressure gauge is included as standard on regulator units for continuous monitoring of regulated output pressure at the FRL station.

Technical Specifications

General Specifications

Certifications & Compliance

Typical Applications & Industries

General Industrial Machine Air Preparation

• Main machine air inlet FRL station for industrial automation systems with 1/4" to 1/2" compressed air circuits, providing filtration, regulated pressure, and lubrication for all downstream pneumatic components from a single modular assembly.
• Pneumatic cylinder and actuator supply in manufacturing automation where mid-size port circuits require 50 to 100 scfm of filtered, regulated, and lubricated air for normal cycle operation.
• Pneumatic control panels with solenoid valve manifolds and pneumatic logic devices requiring stable regulated inlet pressure from an FRL combination installed at the panel air inlet.
• Maintenance and service shop air preparation stations where a modular Mid-Size Series FRL provides filtered, regulated, and lubricated supply air for pneumatic tools and testing equipment.

Automotive Manufacturing and Assembly

• Automotive body shop automation with 1/4" to 1/2" pneumatic circuits on welding fixtures, clamping systems, and material handling robots requiring consistent filtered, regulated, and lubricated air.
• Final assembly line pneumatic tools and actuators where a Mid-Size Series FRL combination supplies tool circuits at regulated pressure with lubrication for torque wrenches, riveters, and nut runners.
• Paint and coating line pneumatic system air preparation supplying spray gun operators and fluid transfer circuits with filtered, regulated air from mid-size FRL stations.
• Automotive parts stamping and press operations with pneumatic die cushion, clutch-brake control, and material feed circuits requiring filtered and regulated air supply.

Packaging and Material Handling

• Case erecting, carton sealing, and palletizing systems with 1/2" and 3/8" main pneumatic supply circuits requiring filtered, regulated, and lubricated air from a centrally located modular FRL station.
• Conveyor systems, diverters, and pneumatic sorters with multiple actuators requiring consistent supply pressure and lubrication from a mid-size FRL combination installed at the system air inlet.
• Form-fill-seal packaging equipment with 1/4" to 1/2" pneumatic circuits for product handling, seal bar actuation, and conveyor drives requiring reliable air preparation at the machine inlet.
• Stretch wrapping and shrink tunneling equipment with pneumatic film tensioning, indexing, and clamping circuits served by a Mid-Size Series FRL station.

Food and Beverage Processing

• Food processing conveyor, sorting, and filling machine pneumatic systems requiring filtered, regulated, and lubricated supply air from a Mid-Size Series FRL installed at the machine air inlet.
• Beverage bottling line actuators, transfer arms, and air-operated valves with 1/4" to 1/2" pneumatic circuits requiring reliable air preparation for continuous production operation.
• Dairy, bakery, and snack food processing equipment with pneumatic portion control, packaging actuation, and transfer mechanisms served by mid-size FRL combinations at each equipment station.

Woodworking and Building Products Manufacturing

• Cabinet and furniture manufacturing air preparation for CNC routers, pneumatic clamps, and sanding equipment using 1/4" to 1/2" circuits that require filtered and regulated air.
• Door and window fabrication line pneumatics with glass handling, frame assembly, and pneumatic clamping circuits served by Mid-Size Series FRL stations at each workstation air supply.
• Building products manufacturing with pneumatic nail guns, fasteners, and assembly actuators requiring consistent air preparation from modular FRL combinations.

Process Industries and Fluid Control

• Chemical processing plant pneumatic actuator instrument air supply where a mid-size FRL combination provides filtered, regulated air to control valve positioners and pneumatic actuators.
• Water and wastewater treatment pneumatic actuated valve supply circuits with 1/4" to 1/2" ports requiring filtered and regulated instrument air from dedicated FRL stations.
• Utilities and power generation facility pneumatic instrument air preparation for control valve actuators, damper drives, and pneumatic instrumentation in 1/4" to 1/2" supply circuits.

Ordering and Model Number Configuration

The Mid-Size Series FRL components are ordered individually as filter, regulator, or lubricator units, and assembled into modular combinations using standard connection hardware. Specify port size, bowl material, drain type, regulator function, and lubricator type when ordering. Contact ROSS Controls at (800) 438-7677 or visit rosscontrols.com for complete ordering information.

Port sizes available: 1/4", 3/8", and 1/2" NPT.

Filter bowl material: polycarbonate plastic with shatterguard (150 psig maximum), or zinc metal (200 psig maximum).

Filter drain options: internal automatic drain, or manual drain.

Regulator type: piston-type. Function: self-relieving (standard) or non-relieving.

Lubricator type: sight-feed for visible oil delivery rate monitoring.

For complete catalog part numbers, dimensional drawings, and modular assembly configurations, visit rosscontrols.com or contact ROSS Controls technical sales.

Accessories

Modular Mounting Brackets

Modular bracket systems allow Mid-Size Series filter, regulator, and lubricator units to be interconnected side-by-side and mounted on a wall, panel, or pipe with a single bracket assembly.

Replacement Filter Elements

Replacement filter elements are available for Mid-Size Series filter units in 5-micron and 40-micron particulate removal grades.

Pressure Gauges

Replacement and additional pressure gauges are available for the Mid-Size Series regulator units.

Bowl Guard

Polycarbonate bowl shatterguard protects the bowl from impact damage while retaining visual access to the condensate level indicator.

Related Products & Accessories

• 146 Miniature Series FRL Combination - Inline FRL combination for 1/8" and 1/4" port sizes with flow to 19 scfm (538 l/min). https://www.rosscontrols.com/en/series/146-miniature-series
• MD3 Series FRL Combination - Higher flow modular FRL combination for 1/4" to 1/2" port sizes with flow to 110 scfm (3115 l/min). https://www.rosscontrols.com/en/series/148-md3-series
• 76 Mid-Size Series Filter - Individual mid-size series filter component for 1/4" to 1/2" port sizes, flow to 75 scfm (2124 l/min). https://www.rosscontrols.com/en/series/76-mid-size-series
• 106 Mid-Size Series Lubricator - Individual mid-size sight-feed lubricator for standalone or modular installation. https://www.rosscontrols.com/en/series/106-mid-size-lubricator
• 149 Full-Size Series FRL Combination - Full-size FRL combination for port sizes 1/4" to 3/4" with flow to 138 scfm (3906 l/min). https://www.rosscontrols.com/en/series/149-full-size-series

Frequently Asked Questions (FAQ)

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

A: The Mid-Size Series FRL combination delivers maximum flow of 100 scfm (2832 l/min) at port sizes from 1/4" to 1/2".

Q: What port sizes are available?

A: The Mid-Size Series is available in 1/4", 3/8", and 1/2" NPT port sizes.

Q: What is modular mounting?

A: Modular mounting allows individual filter, regulator, and lubricator units to be connected side-by-side using manifold connection hardware and a common support bracket. The modular assembly can then be mounted as a single unit on a wall, panel, or pipe support, forming a compact FRL station.

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

A: The polycarbonate bowl with shatterguard provides visual monitoring of condensate level while the zinc shatterguard protects the bowl from impact damage. The zinc metal bowl offers a fully opaque metal enclosure for environments with greater mechanical hazard, higher ambient temperatures (up to 150 degrees F), or higher operating pressures (up to 200 psig).

Q: What is a sight-feed lubricator?

A: A sight-feed lubricator has a visible window or drop sight tube that allows the operator to observe oil dripping into the air stream during operation. This provides direct visual confirmation that lubrication is occurring and allows the delivery rate to be monitored and adjusted. The sight-feed design is particularly useful during commissioning and maintenance to verify proper lubricator function.

Q: Can the Mid-Size Series be used without the lubricator?

A: Yes. The modular design allows the FRL to be assembled as a filter-only, filter/regulator, or filter/regulator/lubricator combination. Omit the lubricator when downstream components use pre-lubricated or non-lubricated seals, or when instrument air quality requirements prohibit oil in the compressed air stream.

Q: What drain option should I select?

A: Select the internal automatic drain for applications with high condensate volume, high humidity environments, or where continuous unattended operation is required. Select the manual drain for lower condensate volume applications where the operator performs scheduled draining during maintenance intervals.

Q: What is the maximum operating pressure?

A: Maximum operating pressure is 150 psig (10 bar) for units with polycarbonate bowls and 200 psig (14 bar) for units with zinc metal bowls.

Q: What temperature range is the Mid-Size Series rated for?

A: Units with polycarbonate bowls are rated for 40 to 125 degrees F (4 to 52 degrees C). Units with zinc metal bowls are rated for 40 to 150 degrees F (4 to 66 degrees C).

Q: How should the FRL combination be oriented during installation?

A: Mount with the bowls in the downward (vertical) position to allow condensate to collect at the bowl drain for proper expulsion. The FRL station should be positioned to allow access to the drain valves and lubricator fill port during routine maintenance.

Q: How do I set the lubrication rate on the sight-feed lubricator?

A: Adjust the lubrication rate needle valve on the lubricator while observing the sight glass or drop sight tube. The standard starting rate is approximately one drop of oil per minute per pneumatic actuator or tool downstream. Adjust the rate based on actual lubricant consumption and downstream component requirements.

Q: Are replacement filter elements available?

A: Yes. Replacement filter elements for the Mid-Size Series are available through ROSS Controls in 5-micron and 40-micron particulate removal grades. Contact ROSS at (800) 438-7677 or visit rosscontrols.com to order replacement elements.

Q: Where can I find catalog part numbers and dimensional drawings?

A: Complete catalog part numbers, dimensional drawings, and technical data for the Mid-Size Series are available at rosscontrols.com. Contact ROSS Controls technical sales at (800) 438-7677 for configuration assistance.

Installation & Maintenance Guidelines

• Mount the Mid-Size Series FRL assembly with the bowls in the downward (vertical) position to ensure condensate collects at the bowl drain for proper expulsion.
• Install the units in the correct sequence: filter (inlet) - regulator (middle) - lubricator (outlet). Filtered air must enter the regulator and lubricated air must exit last to protect the regulator diaphragm or piston from contaminated air and prevent oil from flooding upstream components.
• Verify that the flow direction arrow on each unit body is aligned with the compressed air flow direction before making port connections.
• Apply appropriate thread sealant to all NPT port connections. Tighten connections to the torque specified in the ROSS Controls installation instructions for the Mid-Size Series.
• After making all plumbing connections, pressurize the system gradually and inspect all connections, bowl seals, and port threads for air leakage using an approved leak detection solution.
• Set regulated output pressure by pulling or turning the regulator adjustment knob to unlock it, rotating clockwise to increase pressure or counterclockwise to decrease, observing the gauge, and locking at the set point.
• Fill the lubricator bowl with recommended petroleum-based oil (ISO viscosity grade 32 or lighter) to the maximum fill level indicated on the bowl. Do not overfill.
• Adjust the lubricator oil delivery rate using the needle valve on the lubricator while observing the sight glass. A starting rate of approximately one drop per minute per downstream actuator is typical.
• For modular assemblies, verify that all modular connection hardware is properly tightened and sealed between adjacent units to prevent internal air leakage at module interfaces.
• For automatic drain models, confirm that the drain operates correctly after installation by observing condensate discharge during normal system operation.
• Inspect and drain manual drain units on a scheduled basis appropriate to the condensate volume in the system. Never allow condensate to overflow into the compressed air outlet.
• Replace filter elements when differential pressure across the filter reaches the service threshold, or at the scheduled maintenance interval. Always shut off inlet pressure before removing the bowl for element replacement.

Warranty & Global Support

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

Technical support and product configuration assistance is available through ROSS Controls at (800) 438-7677 or rosscontrols.com.

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

For complete technical data, dimensional drawings, and ordering information for the Mid-Size Series FRL combination, visit rosscontrols.com or contact ROSS Controls technical sales.