MD4 Series Port Sizes 1/4 to 3/4; Flow to 158 scfm (4475 l/min)

Product Overview

The ROSS Controls MD4 Series Clean Air Package is the high-flow counterpart to the MD3 Clean Air Package, delivering three-stage compressed air filtration for applications requiring port sizes from 1/4 to 3/4 inch and flow capacities up to 158 scfm (4,475 l/min). Each assembly integrates a 5-micron particulate filter, a coalescing filter (0.3-micron or 0.01-micron), and an activated carbon adsorbing filter in a single modular assembly that produces outlet air with residual oil content of no more than 0.01 mg/m3, satisfying ISO 8573-1 Class 1 oil purity requirements.

The MD4 Clean Air Package addresses the performance gap that exists when high-throughput production processes require both elevated flow capacity and the highest available compressed air purity. Port sizes of 3/8, 1/2, and 3/4 inch cover the primary flow ranges in medium and large pneumatic systems, while the integrated three-stage filtration eliminates the individual engineering effort of specifying, ordering, and connecting separate filter components. Optional internal float drain, automatic external drain, and manual drain configurations are available on the particulate and coalescing stages to match different maintenance and condensate management requirements.

A differential pressure gauge on the coalescing filter stage provides a continuous visual indication of element loading status, allowing maintenance teams to replace coalescing elements at the appropriate time without requiring separate instrumentation. The adsorbing filter stage uses a manual drain and scheduled element replacement based on air volume and inlet contamination concentration. As with the MD3 Clean Air Package, the MD4 version supports integration of L-O-X lockout valves directly into the modular assembly for compliant energy isolation during element maintenance.

Bowl options for the MD4 Clean Air Package include polycarbonate with steel shatterguard for standard conditions, metal aluminum for elevated temperature and pressure environments, and extended metal aluminum for the adsorbing stage when flow capacity must be increased without upsizing port connections. The extended adsorbing bowl accommodates the R-A115-118E9 cartridge, providing up to 50 percent greater flow through the adsorbing stage compared to the standard 9 oz bowl.

Key Engineering Features

• Three-Stage Clean Air Filtration - Pre-configured assembly of 5-micron particulate filter, coalescing filter (0.3 or 0.01 micron), and activated carbon adsorbing filter in a single modular unit eliminates individual component selection and inter-unit pipe connections.
• Higher Flow Capacity Than MD3 - Port sizes to 3/4 inch and maximum flow to 158 scfm (4,475 l/min) make the MD4 Clean Air Package the correct selection when MD3 series flow capacity is insufficient for the application.
• Adsorbing Filter with Activated Carbon Element - Third-stage activated carbon element removes oil vapors, hydrocarbon vapors, and odors from compressed air, including contaminants from alcohols, esters, and ketones that coalescing filtration cannot remove.
• Differential Pressure Gauge on Coalescing Filter - Integral differential pressure gauge on the coalescing filter stage provides a visual indication when the coalescing element is loaded and requires replacement, supporting timely maintenance intervention.
• Modular Mounting - All three filter stages assemble modularly with shared tie rod hardware and inter-unit sealing, enabling direct connection to other ROSS MD4 FRL components without external pipe fittings.
• Multiple Bowl and Drain Options - Polycarbonate, metal aluminum, and extended aluminum bowl options combined with automatic drain, internal float drain, and manual drain configurations address the widest range of system pressure, temperature, and condensate management requirements.
• Optional L-O-X Lockout Valve Integration - L-O-X energy isolation lockout valve integrates directly into the modular assembly at the inlet for compliant lockout/tagout during filter element maintenance, eliminating the need for a separate upstream isolation device.
• ISO 8573-1 Class 1 Oil Purity - The three-stage assembly with 0.01-micron coalescing and activated carbon adsorbing delivers outlet air with residual oil no greater than 0.01 mg/m3, the highest oil purity class in ISO 8573-1.
• Extended Bowl for 50% Greater Adsorbing Flow - Extended aluminum bowl on the adsorbing stage accommodates the R-A115-118E9 cartridge, providing up to 50 percent greater flow capacity through the adsorbing stage without increasing port size.

Technical Specifications

General Specifications

Certifications & Compliance

Typical Applications & Industries

Food and Beverage Manufacturing

• High-throughput food packaging lines where large pneumatic systems supply compressed air to product-contact filling, sealing, and labeling machines at high cycle rates, requiring both the 3/4 inch port capacity of the MD4 and the ISO 8573-1 Class 1 oil purity of the Clean Air Package configuration.
• Beverage bottling and can-filling operations where compressed air activates high-speed filling valves, container handling, and cap-pressing operations at production rates that exceed the flow capacity of MD3-sized filters.
• Dairy and meat processing automation where pneumatic conveyors, portion-cutting systems, and packaging robots require continuous high-volume clean air supply in facilities operating under HACCP and FDA food safety management plans.
• Ingredient conveying systems where bulk powder, flour, or sugar is transferred pneumatically in direct contact with compressed air, requiring both high flow capacity and zero oil contamination to maintain product purity.
• Coffee and tea processing where compressed air for product handling, packaging, and flushing must be free of hydrocarbon odors that would alter the aromatic profile of the finished product.

Pharmaceutical and Biotechnology

• Large-scale solid dosage form manufacturing (tablets, capsules, granules) where high-volume compressed air for pneumatic transfer, granulator operation, and packaging line actuation must be validated to cGMP standards for instrument air quality throughout multi-shift production.
• Bioreactor and fermentation systems in biological drug manufacturing where compressed air for sparging, agitation, and gas blanket delivery must be free of hydrocarbons to prevent product contamination and maintain cell culture viability in production-scale vessels.
• Sterile injectable manufacturing lines where compressed air for isolator pressurization, barrier system operation, and robotic assembly of pre-filled syringes and vials must meet the strictest pharmaceutical air quality requirements.
• Medical device manufacturing facilities where Class III medical device assembly requires clean room air quality throughout production operations, and where compressed air systems must pass air quality validation as part of manufacturing process qualification.

Electronics and Semiconductor

• High-volume printed circuit board assembly SMT lines using multiple pick-and-place machines, reflow ovens, and selective soldering systems where the cumulative compressed air demand exceeds 125 scfm, requiring the MD4 series flow capacity with equivalent air purity.
• Large-format semiconductor wafer inspection and metrology systems where high-flow compressed air for stage positioning, robotics, and environmental control must maintain Class 1 air quality throughout the measurement and inspection process.
• Data center and server manufacturing where pneumatic component assembly, testing, and packaging operations require sustained high-flow clean air supply, and where contamination of server components would cause field failures.

Automotive Refinishing and OEM Finishing

• Automotive OEM paint lines with multiple simultaneous spray stations where total compressed air demand for atomization exceeds the capacity of MD3 series filters, and where paint quality specifications require zero oil contamination at all spray zones.
• Large-format powder coating ovens and line systems where compressed air for booth operations, conveyor actuation, and finishing equipment requires continuous high-volume oil-free supply to prevent coating adhesion failures.
• Automotive glass laminating lines where compressed air for cutting, handling, and bonding processes must be free of oil contaminants to ensure interlayer adhesion and final product optical clarity.

Aerospace and Defense Manufacturing

• Composite airframe manufacturing where large pneumatic autoclave loading systems, automated fiber placement machines, and pressure bonding operations require high-flow oil-free compressed air over extended production cycles.
• Avionics test facilities where compressed air for environmental test chambers, pneumatic loading fixtures, and test article pressurization must meet aerospace supplier quality requirements for air purity.
• Engine test cell compressed air supply where high-flow instrument-quality air powers pneumatic actuators, test cell door systems, and precision measurement equipment in close proximity to high-value test articles.

Chemical and Process Industries

• Process instrument air systems at refinery and petrochemical facility instrument air headers where large flow demands require the MD4 body size, and where downstream control valve positioners, analyzers, and pneumatic controllers require clean, oil-free air to operate reliably.
• Specialty chemical blending and filling where compressed air contacts bulk chemical intermediates or finished products and must be free of hydrocarbons to prevent cross-contamination and product specification failures.
• Compressed natural gas (CNG) and industrial gas filling station instrument air where clean air quality is required for safety system actuation and leak detection equipment.

Ordering and Model Number Configuration

The MD4 Clean Air Package model number is configured by selecting bowl size, bowl drain type, pipe size, cap color, differential pressure gauge option, coalescing element grade, and optional lockout valve.

Select coalescing element grade A (0.3-micron) for general clean air; select grade B (0.01-micron) for ISO 8573-1 Class 1 oil purity compliance in food, pharmaceutical, and electronics applications.

For BSPP (G) threads, use pipe size codes C (3/8), D (1/2), or E (3/4).

Internal float drain option requires minimum 30 psig (2 bar) inlet pressure for float activation. For systems operating below 30 psig, use manual drain.

The extended metal bowl option on the adsorbing stage uses the R-A115-118E9 element and increases adsorbing flow capacity by up to 50 percent.

The lockout valve integrates at the modular assembly inlet and provides OSHA-compliant energy isolation for all three filter stages during maintenance.

Related Products & Accessories

• MD3 Clean Air Package (Series 87) - Three-stage clean air filtration in MD3 body size covering port sizes 1/4 to 1/2 inch with flow to 125 scfm. https://www.rosscontrols.com/en/series/87-md3-series
• MD4 Series Adsorbing Filters (Series 86) - Individual adsorbing filter units in the MD4 body for applications where only the activated carbon adsorbing stage is needed. https://www.rosscontrols.com/en/series/86-md4-series
• Adsorbing Filter Elements MD3 and MD4 - Replacement activated carbon cartridges for MD3 and MD4 adsorbing filter stages. https://www.rosscontrols.com/en/series/2012-adsorbing-filter-element
• Silencers and Reclassifiers (Series 89) - Inline sintered bronze reclassifiers and silencers for exhaust noise reduction and oil separation. https://www.rosscontrols.com/en/series/89-silencers-reclassifiers

Frequently Asked Questions (FAQ)

Q: What are the filtration stages in the MD4 Clean Air Package?

A: The MD4 Clean Air Package includes three stages: Stage 1 is a 5-micron particulate filter, Stage 2 is a coalescing filter rated at 0.3-micron or 0.01-micron, and Stage 3 is an activated carbon adsorbing filter. All three stages are pre-assembled in a single modular unit.

Q: How does the MD4 Clean Air Package differ from the MD3 version?

A: The MD4 Clean Air Package covers port sizes 3/8, 1/2, and 3/4 inch with maximum flow to 158 scfm (4,475 l/min), compared to the MD3 which covers 1/4, 3/8, and 1/2 inch ports with flow to 125 scfm (3,540 l/min). Both deliver the same three-stage filtration performance and ISO 8573-1 Class 1 oil purity. The MD4 is the correct selection when system flow requirements or port sizes exceed the MD3 range.

Q: What outlet air quality does the MD4 Clean Air Package provide?

A: Configured with the 0.01-micron coalescing element (grade B), the MD4 Clean Air Package delivers outlet air with residual oil content of no more than 0.01 mg/m3, which is ISO 8573-1 Class 1 oil purity. This is the highest oil purity classification in the ISO compressed air quality standard.

Q: What drain options are available for the MD4 Clean Air Package?

A: The particulate and coalescing filter stages support automatic drain (minimum 15 psig for polycarbonate, or 30 psig for float drain), internal float drain, or manual drain. The adsorbing filter stage uses manual drain only. Select automatic drain where possible for maintenance-free condensate removal, especially in the particulate and coalescing stages where liquid accumulation is significant.

Q: What is the minimum operating pressure for automatic drain models?

A: Automatic drain models for polycarbonate bowls require a minimum inlet pressure of 15 psig (1 bar). Internal float drain models require a minimum of 30 psig (2 bar). Metal bowl automatic drain models require a minimum of 15 psig (1 bar). For systems that may operate below 15 psig, specify manual drain models.

Q: Can the MD4 Clean Air Package be integrated with a lockout valve?

A: Yes. L-O-X lockout valves and EEZ-ON soft-start/lockout valves can be integrated directly into the modular assembly at the inlet. This provides OSHA-compliant energy isolation for all three filter stages during element replacement and maintenance, without a separate upstream valve.

Q: How do I know when to replace the coalescing element?

A: The coalescing filter stage includes a differential pressure gauge. Replace the coalescing element when the differential pressure gauge indicates the element is at its replacement threshold. Check the element replacement pressure drop limit in the ROSS Controls product documentation for the specific gauge model.

Q: How do I determine when to replace the adsorbing element?

A: The adsorbing stage does not have a differential pressure indicator because activated carbon does not restrict flow progressively as it exhausts. Schedule adsorbing element replacement based on system air volume throughput, inlet hydrocarbon concentration, and manufacturer service interval recommendations. Outlet air quality testing using hydrocarbon analyzers confirms element performance status.

Q: What replacement elements are used in the MD4 Clean Air Package?

A: Stage 1 (5-micron): R-A115-106PE5. Stage 2 (coalescing, 0.01 micron): consult ROSS Controls for the appropriate model based on bowl type. Stage 3 (adsorbing, standard bowl): R-A115-117E9. Stage 3 (adsorbing, extended bowl): R-A115-118E9.

Q: Is the MD4 Clean Air Package available with BSPP threads?

A: Yes. BSPP (G) thread versions are available in 3/8 G (code C), 1/2 G (code D), and 3/4 G (code E) port size configurations.

Q: What is the maximum operating pressure for the MD4 Clean Air Package?

A: For polycarbonate bowls with manual drain, maximum pressure is 150 psig (10 bar). For metal aluminum bowls with automatic or manual drain, maximum pressure is 200 psig (14 bar). All stages in the assembly must be rated for the system operating pressure; the polycarbonate bowl is the limiting factor in mixed configurations.

Q: Can I select different bowl types for different stages in the same assembly?

A: Yes, bowl type can be mixed across stages within the MD4 Clean Air Package assembly. However, the maximum allowable pressure for the complete assembly is determined by the lowest-rated bowl type installed. Consult ROSS Controls when specifying mixed bowl configurations to confirm pressure rating compatibility.

Q: What are the benefits of the extended aluminum bowl on the adsorbing stage?

A: The extended bowl accommodates the R-A115-118E9 activated carbon cartridge, which provides up to 50 percent greater air flow through the adsorbing stage compared to the standard R-A115-117E9 cartridge. This increases the flow capacity of the adsorbing stage without requiring a larger port size, and also extends the service interval between element replacements by increasing the mass of activated carbon available for adsorption.

Installation & Maintenance Guidelines

• Install the MD4 Clean Air Package with flow direction matching the directional marking on the filter body. Air must enter the particulate filter first and exit through the adsorbing filter last.
• Mount the assembly in the vertical position with bowls facing downward to optimize condensate collection and automatic drain operation.
• Verify that no lubricated air enters the filter assembly. Install any downstream lubricators after the complete filter assembly, never upstream of any filtration stage.
• For automatic drain stages: ensure that inlet pressure will remain above the minimum drain activation pressure (15 psig for automatic drain; 30 psig for float drain) during all phases of system operation.
• Monitor the coalescing filter differential pressure gauge during operation. Replace the coalescing element when the gauge reading reaches the element replacement threshold to maintain air quality and avoid excessive pressure drop.
• Replace the adsorbing element on a scheduled basis determined by air volume throughput and inlet contamination concentration. Confirm element performance by periodic outlet air hydrocarbon testing.
• When installing the L-O-X lockout valve option, ensure that the lockout valve model matches the assembly inlet pressure and pipe size, and update plant lockout/tagout procedures to identify the new energy isolation point.
• Account for bowl removal clearance when specifying the installation space: add 3.1 inches (79 mm) for standard bowls and 6.1 inches (155 mm) for the extended adsorbing bowl. The modular assembly requires clear access to all three bowl positions for element replacement.
• Purge the filter assembly with compressed air for a minimum of 10 minutes after initial installation or after element replacement before returning to production service.
• In high-vibration installation environments, use bracket hardware to secure the assembly and prevent vibration-induced loosening of inter-unit connections and bowl retaining rings.

Warranty & Global Support

ROSS Controls provides a one-year warranty on all products, covering defects in material and workmanship from 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 +1-248-764-1800 or visit rosscontrols.com for product configuration, technical support, and distributor locator services.

For complete technical data, dimensional drawings, and ordering information, visit the ROSS Controls MD4 Clean Air Package product page or contact ROSS Controls at (800) 438-7677.

Download Catalog: https://www.rosscontrols.com/en/series/88-md4-series