MD3 Series Port Sizes 1/4" to 1/2"; Flow to 110 scfm (3115 l/min)

Product Overview

The ROSS Controls MD3 Series is a high-performance modular Filter Regulator Lubricator (FRL) combination product line for 1/4" to 1/2" port size compressed air systems. The MD3 Series delivers up to 110 scfm (3115 l/min) of combined filtration, pressure regulation, and lubrication from a modular manifold assembly, providing higher flow capacity than standard mid-size FRL combinations at equivalent port sizes.

The MD3 Series is the high-flow counterpart to the Mid-Size Series within the ROSS Controls FRL product range, engineered for applications where 1/4" to 1/2" port circuits must support the full flow demands of high-cycle automation, multiple actuators sharing a common supply, or centralized FRL stations serving large machine pneumatic systems.

The filter component offers three bowl options: a polycarbonate plastic bowl with steel shatterguard, an aluminum bowl with a clear nylon sight glass, and an extended aluminum lubricator bowl with sight glass. The MD3 Series adds the electronic drain option to the standard automatic and manual drain choices, providing timed or sensor-triggered condensate expulsion for applications where compressed air loss from continuous automatic drains must be minimized.

The self-relieving diaphragm-type regulator provides high sensitivity pressure regulation with two gauge ports for connection of both an inlet pressure gauge and an outlet pressure gauge simultaneously, enabling differential pressure monitoring across the regulator at the FRL station. The lubricator is an integral component of the MD3 combination assembly. All three components mount in a modular side-by-side configuration using standard MD3 Series connection hardware.

Key Engineering Features

• Higher Flow Capacity at Mid-Size Port Dimensions - Delivers up to 110 scfm (3115 l/min) at 1/4" to 1/2" port sizes, exceeding the flow capacity of the standard mid-size FRL series at the same port dimensions, enabling the MD3 to serve higher-demand pneumatic circuits without increasing port size.
• Three Bowl Material Options - Available with polycarbonate plastic bowl with steel shatterguard, aluminum bowl with clear nylon sight glass, and extended aluminum lubricator bowl with sight glass, providing configuration flexibility for different operating environments and condensate volume requirements.
• Electronic Drain Option - Electronic drain provides timed or demand-triggered condensate expulsion, minimizing compressed air loss compared to continuous automatic float drains in high-flow applications with intermittent condensate generation.
• Four Drain Type Selections - Internal automatic drain, manual drain, and electronic drain options provide complete flexibility in condensate management strategy for different application condensate volumes and operating schedules.
• Self-Relieving Diaphragm-Type Regulator - Diaphragm-type regulator provides high sensitivity pressure control with low droop across the flow range, maintaining accurate regulated output pressure in high-demand circuits with variable flow.
• Two Gauge Ports on Regulator - Dual gauge ports allow simultaneous connection of inlet and outlet pressure gauges, enabling monitoring of both supply and regulated pressure from the FRL station for system diagnosis and performance verification.
• Modular Mounting Design - Components interconnect side-by-side in a modular manifold assembly that can be expanded or reconfigured to match the air treatment stages required for each application.
• Non-Relieving Regulator Option - Non-relieving regulator option is available for circuit configurations where venting downstream pressure to atmosphere is not permitted or where downstream pressure must be retained during a regulator set point reduction.

Technical Specifications

General Specifications

Certifications & Compliance

Typical Applications & Industries

High-Flow Automation and Machine Tools

• Machine tool pneumatic circuits with 1/4" to 1/2" supply ports requiring 80 to 110 scfm to serve simultaneous tool changes, workholding clamping, coolant purge, and spindle clearing air circuits from a single MD3 FRL station.
• High-cycle automation cells with multiple pneumatic actuators sharing a common 1/2" supply where the MD3 Series high-flow FRL maintains adequate regulated pressure even at peak demand.
• Robotic welding cells and material handling systems with 1/4" to 1/2" pneumatic circuits requiring filtered, regulated, and lubricated supply air at flow rates exceeding standard mid-size FRL capacity.
• Pneumatic press and stamping machine air preparation where die cushion, clutch-brake, and material handling circuits share a common 1/2" FRL station and require high flow at consistent regulated pressure.

Automotive and Tier-1 Supplier Manufacturing

• Automotive assembly line body shop tooling with multiple pneumatic nut runners, riveters, and drill motors sharing an MD3 FRL station at 1/2" supply where 100 scfm-class flow is required during simultaneous tool operation.
• Engine and transmission assembly fixtures with pneumatic clamping, gauging, and part handling circuits requiring high-flow filtered and regulated air from a central FRL station.
• Automotive paint line pneumatic equipment including air motors, spray atomizers, and pneumatic valve actuators served by a high-flow MD3 Series FRL combination at the line inlet.
• Tier-1 supplier machining and assembly cells with multiple CNC machine pneumatic circuits requiring centralized high-flow air preparation at a shared 1/2" supply header.

Packaging and Converting Equipment

• High-speed packaging lines with multiple pneumatic actuators, pneumatic product transfer, and air-ejection systems sharing a 1/2" supply line requiring MD3 class flow to maintain pressure during peak demand cycles.
• Flexible packaging and film converting equipment with pneumatic web tensioners, dancer arms, and nip roller actuators requiring stable regulated pressure from a high-flow FRL station.
• Contract packaging operations running multiple packaging machines from a shared compressed air manifold where individual MD3 Series FRL stations provide regulated and lubricated air to each machine.
• Corrugated box making and converting equipment with pneumatic blanket clamping, die cutting, and stacker systems requiring high-flow filtered and regulated air.

Food and Beverage Processing

• Beverage filling and capping lines with high-speed pneumatic actuators for bottle handling, cap sorting, and seal inspection requiring MD3 flow capacity at 1/2" supply connections.
• Food processing equipment with multiple pneumatic actuators per machine including portioning, slicing, conveying, and inspection systems where simultaneous operation requires 100 scfm class FRL capacity.
• Dairy and liquid food processing with CIP-compatible equipment and stainless steel components served by MD3 FRL stations providing filtered, regulated air to pneumatic actuators and air-operated valves.
• High-volume baking and snack food automation where oven loading, product handling, and packaging pneumatics all share a central FRL supply requiring the flow capacity of the MD3 Series.

Electronics and Semiconductor Manufacturing

• PCB handling automation with vacuum generators, pick-and-place heads, and pneumatic transport systems requiring clean, filtered air from an MD3 FRL combination at the main supply inlet.
• Semiconductor process equipment support systems where electronic drain operation eliminates scheduled drain servicing and maintains consistent air quality without operator intervention.
• Electronics assembly conveyor and transfer systems with multiple pneumatic actuators per machine requiring high-flow filtered and regulated air from a single MD3 Series FRL station.

Compressed Air System Monitoring and Diagnostics

• Applications requiring simultaneous supply and regulated pressure monitoring, where the MD3 Series dual gauge ports enable connection of both an inlet and outlet pressure gauge to monitor regulator differential pressure at the FRL station.
• Process lines with energy management requirements where the electronic drain minimizes compressed air waste compared to continuous float drains, contributing to lower system operating costs.
• Centralized FRL stations on long pneumatic distribution headers where differential pressure monitoring across the regulator confirms filter element loading condition and supply pressure adequacy.

Ordering and Model Number Configuration

The MD3 Series FRL components are ordered individually as filter, regulator, or lubricator units and assembled into modular combinations. Specify port size, bowl material, drain type, regulator function, and electronic drain option when ordering. Contact ROSS Controls at (800) 438-7677 or visit rosscontrols.com for complete ordering configuration.

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

Bowl material options: polycarbonate with steel shatterguard (150 psig maximum), aluminum with nylon sight glass (200 psig maximum), or extended aluminum lubricator bowl with sight glass.

Drain options: internal automatic drain, manual drain, or electronic drain. Electronic drain is recommended for high-flow applications where compressed air conservation is important.

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

Two gauge ports standard on regulator for simultaneous inlet and outlet pressure monitoring.

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

Accessories

Modular Connection Hardware

MD3 Series modular bracket and connection hardware assembles individual filter, regulator, and lubricator units into a compact side-by-side modular FRL station with a single set of supply and outlet ports.

Electronic Drain Controllers

Timer-based and demand-sensing electronic drain controllers are available for MD3 Series filter units with electronic drain connections, enabling programmed drain intervals or condensate-level-triggered drain operation.

Replacement Filter Elements

Replacement filter elements for the MD3 Series filter units are available in 5-micron and 40-micron particulate grades.

Pressure Gauges

Replacement and additional pressure gauges for MD3 Series regulator units, available in various dial sizes and pressure ranges for both inlet and outlet gauge port connections.

Related Products & Accessories

• 147 Mid-Size Series FRL Combination - Standard mid-size modular FRL combination for 1/4" to 1/2" port sizes, flow to 100 scfm (2832 l/min). https://www.rosscontrols.com/en/series/147-mid-size-series
• 149 Full-Size Series FRL Combination - Full-size FRL combination for 1/4" to 3/4" port sizes with flow to 138 scfm (3906 l/min). https://www.rosscontrols.com/en/series/149-full-size-series
• MD3 Series Filter - Individual MD3 Series filter component for standalone or modular installation, 1/4" to 1/2" ports. https://www.rosscontrols.com/en/series/72-md3-series
• MD4 Series FRL Combination - Higher-flow MD4 FRL combination for 3/8" to 3/4" port sizes with flow to 205 scfm (5806 l/min). https://www.rosscontrols.com/en/series/150-md4-series
• Flow Controls - ROSS flow control valves for actuator speed regulation downstream of FRL assemblies. https://www.rosscontrols.com/en/series/261-flow-controls

Frequently Asked Questions (FAQ)

Q: What is the maximum flow capacity of the MD3 Series FRL?

A: The MD3 Series FRL combination delivers maximum flow of 110 scfm (3115 l/min) at port sizes from 1/4" to 1/2".

Q: What port sizes are available?

A: The MD3 Series is available in 1/4", 3/8", and 1/2" NPT port sizes.

Q: How does the MD3 Series differ from the Mid-Size Series (147)?

A: The MD3 Series provides higher flow capacity (110 scfm versus 100 scfm), adds the electronic drain option, offers three bowl material choices versus two in the Mid-Size Series, and uses a diaphragm-type regulator with dual gauge ports versus the piston-type regulator and single gauge in the Mid-Size Series. The MD3 is preferred for higher-flow and more demanding monitoring requirements.

Q: What is an electronic drain?

A: An electronic drain uses a timer-controlled or demand-sensing solenoid valve to expel condensate from the filter bowl at programmed intervals or when a condensate level sensor triggers drainage. Electronic drains minimize compressed air waste compared to continuous float-type automatic drains by opening only when condensate expulsion is needed.

Q: What are the three bowl material options for the MD3 Series filter?

A: The three bowl options are: (1) polycarbonate plastic with steel shatterguard, combining visual level monitoring and mechanical protection; (2) aluminum with clear nylon sight glass, providing metal construction with retained visual access; and (3) extended aluminum lubricator bowl with sight glass for higher condensate capacity or lubricant reservoir applications.

Q: Why does the MD3 regulator have two gauge ports?

A: The dual gauge ports allow simultaneous connection of an inlet pressure gauge and an outlet pressure gauge, enabling the operator or maintenance technician to monitor both supply pressure and regulated output pressure at the same time. This is useful for diagnosing supply pressure drops, monitoring filter loading, and verifying regulator differential pressure performance.

Q: What type of regulator is used in the MD3 Series?

A: The MD3 Series uses a self-relieving diaphragm-type regulator as standard. Diaphragm-type regulators offer high sensitivity and low droop, maintaining accurate output pressure across a wide flow demand range. A non-relieving option is available for circuits where venting downstream pressure is not permitted.

Q: What is the maximum operating pressure?

A: Maximum operating pressure is 150 psig (10 bar) with polycarbonate bowls and 200 psig (14 bar) with aluminum bowls.

Q: What temperature range is the MD3 Series rated for?

A: Polycarbonate bowl units are rated for 40 to 125 degrees F (4 to 52 degrees C). Aluminum bowl units are rated for 40 to 150 degrees F (4 to 66 degrees C).

Q: What mounting orientation is required?

A: Mount with the bowls in the downward (vertical) position to allow condensate to collect at the bowl drain. The modular assembly should be positioned to allow access to drain valves, filter bowl, and lubricator fill port for routine maintenance.

Q: Can I add or remove components from the MD3 modular assembly after installation?

A: Yes. The modular design allows components to be added or removed from the assembly using standard MD3 modular connection hardware. Follow the installation instructions for disassembly and reassembly procedures. Always depressurize and isolate the FRL assembly before performing any modifications.

Q: How often should the filter element be replaced?

A: Replace the filter element when the differential pressure across the filter reaches the service threshold specified in the ROSS Controls catalog or installation instructions for the MD3 Series. In high-contamination applications, more frequent inspection may be warranted.

Q: Are catalog part numbers and drawings available?

A: Complete catalog part numbers, dimensional drawings, and technical data for the MD3 Series are available at rosscontrols.com. Contact ROSS Controls technical sales at (800) 438-7677 for configuration assistance.

Installation & Maintenance Guidelines

• Mount the MD3 Series FRL assembly with the bowls in the downward (vertical) position to ensure proper condensate collection and drainage.
• Install components in the correct flow sequence: filter first (inlet side), regulator second, lubricator last (outlet side).
• Align the flow direction arrow on each unit body with the compressed air flow direction before making port connections.
• Apply appropriate thread sealant to all NPT port connections. Tighten to the torque values specified in the ROSS Controls installation instructions.
• Pressurize the system gradually after installation and inspect all connections and bowl seals for leakage using approved leak detection solution.
• Connect inlet pressure gauge to the inlet gauge port and outlet pressure gauge to the outlet gauge port on the regulator if differential pressure monitoring is desired.
• Set regulated output pressure using the regulator adjustment knob while observing the outlet pressure gauge, then lock the adjustment.
• For electronic drain models, configure the drain timer interval or sensor setpoint per the application condensate volume requirements and the electronic drain controller instructions.
• Fill the lubricator bowl to the maximum fill level with recommended petroleum-based oil (ISO 32 or lighter). Adjust the oil delivery rate per the application requirement.
• Verify modular connection hardware at all unit-to-unit interfaces is properly seated and tightened to prevent internal air leakage.
• Establish a maintenance schedule for filter element inspection and replacement based on application contaminant levels and the differential pressure threshold in the product catalog.
• Always depressurize and isolate the FRL assembly before performing bowl removal, element replacement, or modular assembly modifications.

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 MD3 Series FRL combination, visit rosscontrols.com or contact ROSS Controls technical sales.