MD4 Series Port Sizes 3/8" to 3/4"; Flow to 230 scfm (6514 l/min)

Actual product may differ from above image. Product details should be verified before purchase.

Filter and regulator consolidated into a single assembly
Modular mounting
Pressure gauge included; two gauge ports
Add on L-O-X® valve – option
Polycarbonate plastic bowl with steel shatterguard, ormetal bowl with sight glass
Automatic drain, or manual drain
Self-relieving diaphragm-type regulator, or non-relieving
Pressure adjustment locking key; tamper-resistant pressure setting

Integrated Filter/Regulators MD4 Series Product Overview

The MD4 Series of Integrated Filter/Regulators provide a streamlined solution by consolidating a filter and regulator into a single assembly. These units are designed for modular mounting, offering easy integration into your system. They come with a pressure gauge and two gauge ports for comprehensive monitoring.

For added functionality, you can opt for an add-on L-O-X® valve. Depending on your specific requirements, you can choose between a polycarbonate plastic bowl with a steel shatterguard or a metal bowl with a sight glass. Additionally, you have the choice between an automatic or manual drain for maintenance.

The regulators in this series are self-relieving and diaphragm-type, although non-relieving options are available. To ensure secure pressure settings, a pressure adjustment locking key is included, offering tamper-resistant control. The MD4 Series Integrated Filter/Regulators provide a versatile and reliable solution for precise air quality management.

Please refer to the side and below for Integrated Filter/Regulators MD4 Series catalogs, installation instructions, and technical data. Additionally, you have the option to filter through all available Integrated Filter/Regulators MD4 Series variant that meets your requirements.

Series Overview ❯

Product Overview

The ROSS Controls MD4 Series Integrated Filter/Regulator is the full-size version of the ROSS MD-series integrated air preparation platform, providing the highest flow capacity in the diaphragm-regulator integrated FR product line. With port sizes from 3/8" to 3/4" and flow capacity to 230 scfm (6514 l/min), the MD4 Series delivers combined filtration and pressure regulation for large industrial pneumatic systems where precise high-pressure regulation and optional integrated lockout capability are required.

The diaphragm-type regulator provides outlet pressure to 175 psig (12 bar) when ordered with a metal bowl, significantly exceeding the capability of standard piston-type full-size units. This higher outlet pressure range makes the MD4 Series well suited for pneumatic pressing, clamping, and high-force actuation circuits that operate at pressures above 125 psig. The diaphragm design also delivers superior pressure sensitivity and lower hysteresis compared to piston regulators, providing tighter regulation under varying flow conditions.

A key feature of the MD4 Series is the optional integrated L-O-X Lockout Valve, which can be added directly to the assembly to provide OSHA-compliant pneumatic energy isolation at the filter/regulator point. This eliminates the need for separate lockout plumbing in the supply line and creates a single consolidated air preparation and energy isolation point. Two gauge ports (front and rear) and a removable pressure adjustment locking key are standard features.

The MD4 Series configurable ordering system allows precise specification of bowl material, filter element type and rating, drain configuration, port size (NPT or BSPP), lockout valve option, gauge range, and reverse flow capability. This makes the MD4 Series a highly versatile platform for full-size pneumatic air preparation across industrial automation, process industry, and machine safety applications.

Key Engineering Features

Highest Flow in MD-Series Diaphragm FR Line - Flow capacity to 230 scfm (6514 l/min) at 3/4" port connections, the highest available in the ROSS MD-series integrated filter/regulator product family, accommodating the main air supply requirements of large automation cells and industrial machinery.
Diaphragm Regulator to 175 psig (12 bar) with Metal Bowl - Diaphragm-type regulator with metal bowl delivers outlet pressure to 175 psig (12 bar), exceeding the capability of standard piston-type full-size FRs and supporting high-force pneumatic circuits in clamping, pressing, and forming applications.
Optional L-O-X Lockout Valve Integration - An L-O-X Lockout Valve can be added directly to the MD4 assembly for integrated OSHA-compliant lockout/tagout energy isolation without separate lockout plumbing, creating a single consolidated air preparation and energy isolation assembly.
Two Gauge Ports (Front and Rear) - Independent gauge ports on both front and rear surfaces allow the pressure gauge to be positioned for optimal visibility regardless of installation orientation, panel layout, or enclosure constraints.
Pressure Adjustment Locking Key - Removable locking key is standard on all MD4 units. After pressure is set to specification, the key is removed to prevent unauthorized adjustment, supporting process consistency and machine safety requirements.
Configurable Part Number System - Structured ordering code allows specification of bowl material, filter element type, drain type, port size, lockout valve option, gauge range, adjustment spring range, and reverse flow configuration, enabling precise unit configuration for each application requirement.
Multiple Filter Element Options - Standard 5-micron polyethylene and optional 40-micron sintered bronze elements provide filtration options. Additional sintered bronze ratings may be available; contact ROSS Controls for the full element range.
Polycarbonate Bowl with Steel Shatterguard - Standard 9-oz (266 ml) polycarbonate bowl provides visual condensate inspection; steel shatterguard protects the bowl and contains fragments for the higher pressures typical of full-size supply circuits.
Metal (Aluminum) Bowl with Clear Nylon Sight Glass - 9-oz (266 ml) aluminum metal bowl extends maximum outlet pressure to 175 psig, operating pressure to 200 psig (auto drain), and upper temperature rating to 175 degrees F (80 degrees C). Must be specified for 175 psig outlet adjustment range.
Reverse Flow Option - Reverse flow configurations allow downstream equipment to back-feed regulated pressure through the unit, useful for multi-source pneumatic circuits and test applications where bidirectional flow capability is required.

Technical Specifications

General Specifications

Parameter	Specification
Series	MD4 Series Full-Size
Mounting Type	Modular
Port Sizes	3/8", 1/2", and 3/4" (NPTF or BSPP/G)
Maximum Flow	230 scfm (6514 l/min)
Regulator Type	Diaphragm; self-relieving (standard) or non-relieving
Filter Element Options	5 micron polyethylene (standard); 40 micron sintered bronze (optional)
Outlet Pressure Range - Standard Spring	Adjustable up to 125 psig (9 bar)
Outlet Pressure Range - High-Pressure Spring (Metal Bowl Only)	Adjustable up to 175 psig (12 bar)
Operating Pressure - Polycarbonate Bowl (Auto Drain)	Up to 150 psig (10 bar)
Operating Pressure - Metal Bowl (Auto Drain)	Up to 200 psig (14 bar)
Operating Pressure - Polycarbonate Bowl (Manual Drain)	0 to 150 psig (0 to 10 bar)
Operating Pressure - Metal Bowl (Manual Drain)	0 to 200 psig (14 bar)
Ambient/Media Temperature - Polycarbonate Bowl	40 to 125 degrees F (4 to 52 degrees C)
Ambient/Media Temperature - Metal Bowl	40 to 175 degrees F (4 to 80 degrees C)
Bowl Capacity	9 oz (266 ml) for both polycarbonate and metal bowl options
Pressure Gauge	0 to 200 psig (0 to 14 bar); 1/4 NPT ports front and rear
Pressure Adjustment	Removable locking key (tamper-resistant)
Panel Mounting Hole	2.05 inch (52.1 mm) diameter
Flow Media	Compressed air

Certifications & Compliance

Typical Applications & Industries

Machine Safety and Lockout/Tagout Compliance

Full-size pneumatic machine air preparation with integrated L-O-X lockout valve, providing a single combined air conditioning and energy isolation point for OSHA 29 CFR 1910.147 compliance without separate lockout hardware in the pneumatic supply line.
Large automated production cells where each machine requires both high-flow air preparation (to 230 scfm at 3/4" connections) and integrated OSHA-compliant lockout capability, enabling maintenance personnel to lock out the machine at the FR assembly with a standard padlock.
Manufacturing lines with multiple machines where standardizing on the MD4 Series with integrated lockout provides consistent energy isolation procedures across all machines in the facility, simplifying lockout/tagout training and documentation.
Heavy automation equipment requiring both high-pressure operation (to 175 psig with metal bowl) and energy isolation, where the MD4 Series with metal bowl and L-O-X option meets both requirements in a single assembly.

High-Pressure and High-Force Applications

Pneumatic pressing and clamping circuits operating at pressures from 125 to 175 psig where the MD4 Series with metal bowl and high-pressure spring option provides the outlet pressure range needed while maintaining the superior pressure sensitivity characteristics of a diaphragm regulator.
Die casting machine pneumatic circuits where high-pressure air supply for ejector cylinders, clamping, and die locking requires reliable filtration and precise pressure control at full-size port connections.
Hydraulic press auxiliary pneumatic circuits where air-operated pre-fill valves, counterbalance circuits, and part detection systems require high-pressure regulated air at 3/4" port connections.
Tire manufacturing and rubber processing pneumatic circuits where consistent high-pressure regulation ensures consistent mold closing forces and cure cycle precision.

Automotive and Heavy Manufacturing

Assembly plant main air preparation serving large automated welding, assembly, and test cells where 230 scfm flow capacity at 3/4" ports accommodates simultaneous operation of multiple high-cycle pneumatic fixtures, nut runners, and transfer actuators.
Automotive stamping and body shop clamping fixture air preparation where the high-pressure diaphragm regulator maintains consistent clamp forces across all fixtures during the production cycle, with the locking key preventing set point drift between shifts.
Engine assembly and powertrain test cell air preparation where precise pressure regulation, high flow capacity, and the option for electronic gauge with reed switch output enable integration with process monitoring and SPC systems.
Tier 1 supplier automation air preparation where modular FRL assemblies combining MD4 Series with compatible ROSS lubricators and lockout valves provide standardized, documented air preparation points across multiple production lines.

Process Industry and Infrastructure

Instrument air preparation in chemical and petrochemical plants where the aluminum bowl resists chemical exposure, high flow capacity serves distributed pneumatic instrument headers, and the diaphragm regulator provides precise pressure control for critical control valve positioners.
Compressed air distribution in manufacturing facilities where MD4 Series units at each major branch provide localized air conditioning with integrated lockout capability, supporting both air quality management and maintenance safety programs.
Natural gas compressor station pneumatic control air preparation where the high-pressure metal bowl configuration and diaphragm regulator precision support critical control functions, and the tamper-resistant locking key maintains set points in remote or unattended installations.

Ordering and Model Number Configuration

The MD4 Series uses a configurable part number system. Build the model number by selecting from the available option codes. Contact ROSS Controls at (800) 438-7677 for assistance configuring the correct model number for your application, particularly for lockout valve and high-pressure spring configurations.

Metal bowl (53M) must be specified when ordering the 0-175 psig (0-12 bar) pressure adjustment range (option code A for adjustment range).

For L-O-X Lockout Valve configurations, add the lockout code (1 for outlet lockout) to the model number.

For reverse flow configurations, specify the appropriate reverse flow option code (F, G, H, or J) based on the required pressure range.

For electronic gauge with reed switch output (options E and C), the switch provides a dry contact signal when regulated pressure drops below or rises above a threshold, enabling integration with machine controls or alarms.

Contact ROSS Controls at (800) 438-7677 for configurations combining multiple options, stainless steel variants, or for high-volume order configurations. All options in red on the ROSS product page must be selected to complete the model number.

Accessories

L-O-X Lockout Valve Add-On

The ROSS L-O-X Lockout Valve integrates directly with the MD4 Series assembly, providing OSHA 29 CFR 1910.147-compliant pneumatic energy isolation with hasp-style lockout capability at the filter/regulator assembly. Available in outlet lockout configuration (code 1). Contact ROSS Controls for L-O-X compatibility and complete integrated model numbers.

Replacement Filter Elements

Four filter element options are available for the MD4 Series. Standard 5-micron polyethylene element is model R-A115-106PE5. Sintered bronze options: 5-micron (R-A115-106E5), 20-micron (R-A115-106E4), and 40-micron (R-A115-106E3). Sintered bronze elements can be cleaned and reused, providing cost-effective service in high-contamination environments.

Rating	Material	Model Number
5 micron (standard)	Polyethylene	R-A115-106PE5
5 micron (optional)	Sintered Bronze	R-A115-106E5
20 micron (optional)	Sintered Bronze	R-A115-106E4
40 micron (optional)	Sintered Bronze	R-A115-106E3

External Drain and Differential Gauge Options

External bowl drain connections and differential pressure gauge options are available for the MD4 Series. External drains allow remote condensate collection. Differential pressure gauges indicate filter element loading status directly. Contact ROSS Controls for model numbers and specifications for these options.

Electronic Gauge with Reed Switch

The MD4 Series supports an electronic gauge option with either normally open (NO, code E) or normally closed (NC, code C) reed switch output. This allows integration of a low-pressure alarm signal with machine controls or centralized monitoring systems. Contact ROSS Controls for the electronic gauge specifications and wiring details.

Frequently Asked Questions (FAQ)

Q: What is the maximum flow capacity of the MD4 Series?

A: The MD4 Series is rated for flow to 230 scfm (6514 l/min). This is the highest flow capacity in the ROSS diaphragm-regulator integrated filter/regulator product line and accommodates the full air preparation requirements of large industrial pneumatic systems at 3/4" port connections.

Q: What is the maximum outlet pressure?

A: The standard configuration provides outlet pressure adjustable up to 125 psig (8.6 bar). When ordered with an aluminum (metal) bowl and the high-pressure spring option (adjustment range code A), outlet pressure is adjustable up to 175 psig (12 bar). The metal bowl must be specified for the 175 psig outlet range.

Q: Why use a diaphragm regulator for a full-size unit?

A: The diaphragm regulator in the MD4 Series provides several advantages over piston-type regulators at full-size flow rates: superior pressure sensitivity (lower droop under varying flow), lower hysteresis, and higher maximum outlet pressure capability when ordered with the high-pressure spring and metal bowl. For applications requiring precise pressure control under varying load conditions or outlet pressures above 125 psig, the MD4 diaphragm design offers meaningful performance advantages.

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

A: Automatic drain models require a minimum inlet pressure of 30 psig (2 bar) for proper float drain operation. Manual drain models have no minimum inlet pressure requirement.

Q: How does the integrated L-O-X Lockout Valve work?

A: The L-O-X Lockout Valve is a separate valve element integrated into the MD4 assembly at the outlet port. When closed and locked, it isolates the downstream pneumatic circuit from the supply, exhausting residual downstream air through the lockout valve exhaust port. A hasp allows one or more padlocks to be applied, physically preventing the valve from being opened during maintenance. This provides OSHA 29 CFR 1910.147-compliant energy isolation at the filter/regulator assembly point.

Q: When must the metal bowl be specified?

A: The metal (aluminum) bowl must be specified when ordering the 0-175 psig (0-12 bar) pressure adjustment range (option code A). The metal bowl is also recommended for applications with inlet pressures above 150 psig, temperatures above 125 degrees F, or environments with chemical exposure that would attack polycarbonate.

Q: What filter element options are available for the MD4 Series?

A: Four element options are available: 5-micron polyethylene (standard, R-A115-106PE5), 5-micron sintered bronze (R-A115-106E5), 20-micron sintered bronze (R-A115-106E4), and 40-micron sintered bronze (R-A115-106E3). The standard polyethylene element provides good general-purpose filtration. Sintered bronze elements are more durable in high-contamination or high-condensate environments and can be cleaned and reused.

Q: What is the reverse flow option?

A: Reverse flow configurations allow air to flow from the downstream (outlet) side back through the regulator to the supply side. This is used in multi-source pneumatic systems or test applications where the downstream circuit may be pressurized by an external source, and the regulator must accommodate bidirectional flow without damaging the diaphragm or check ball mechanism. Four reverse flow pressure ranges are available (codes F, G, H, J).

Q: How does the MD4 compare to the Series 74 Full-Size?

A: Both are full-size modular integrated FRs for 3/8" to 3/4" port sizes. Key differences: the MD4 uses a diaphragm regulator (higher pressure sensitivity, outlet to 175 psig with metal bowl) while the Series 74 uses a piston regulator (maximum outlet 125 psig). The MD4 offers L-O-X lockout valve option, reverse flow options, and electronic gauge with reed switch. The Series 74 offers an external automatic drain option. Select the MD4 when higher outlet pressure capability, lockout valve integration, or reverse flow is required.

Q: Can a stainless steel MD4 version be ordered?

A: Yes. Stainless steel filter/regulator with L-O-X lockout valve combination units are available in the MD4 platform. Contact ROSS Controls at (800) 438-7677 for stainless steel configuration model numbers, appropriate for corrosive environments, marine applications, food and beverage washdown, and pharmaceutical GMP equipment.

Q: Can the MD4 Series be assembled with a lubricator?

A: Yes. The MD4 modular mounting design supports direct assembly with compatible ROSS full-size modular lubricators, creating a complete FR+L or FRL assembly. Contact ROSS Controls for modular interface hardware model numbers and compatible lubricator specifications for the MD4 platform.

Q: What is the panel mounting hole size?

A: The MD4 Series requires a 2.05 inch (52.1 mm) diameter hole for panel mounting. Allow clearance below the unit for bowl removal during maintenance.

Q: What is the warranty?

A: ROSS Controls provides a one-year warranty on all products covering defects in material and workmanship from the date of purchase. Contact ROSS Controls USA at (800) 438-7677 for technical support or warranty claims.

Installation & Maintenance Guidelines

Mount with the bowl oriented downward for proper condensate collection and drain operation.
For automatic (float) drain models, ensure minimum inlet pressure of 30 psig is maintained for proper float drain operation.
Do not exceed rated inlet pressures: 150 psig for polycarbonate bowl, 200 psig for metal bowl (auto drain), 200 psig for metal bowl (manual drain).
For the 175 psig outlet range (adjustment range code A), only the metal bowl configuration (53M) is acceptable. Do not use the high-pressure spring with a polycarbonate bowl.
Set the regulated outlet pressure within the specified adjustment range, then remove the locking key. Store the key securely with authorized maintenance personnel.
When installing with an integrated L-O-X lockout valve, verify the lockout valve is in the OPEN (unlocked) position before pressurizing the system.
For modular FRL assembly with a lubricator, follow ROSS Controls modular assembly instructions to ensure proper interface seal engagement and correct fastener torque.
Use thread sealant or PTFE tape on NPTF connections; apply sparingly to prevent contamination of the air circuit.
Replace the filter element on a scheduled interval based on system contamination level or when pressure drop increases noticeably.
Allow minimum clearance per dimensional data for bowl removal; allow additional clearance for lockout valve length when specified (add 2.3 inches / 58 mm to width dimension).

Warranty & Global Support

ROSS Controls provides a one-year warranty on all products, covering defects in material and workmanship from the 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 (800) 438-7677 or visit rosscontrols.com for product configuration, technical support, and distributor locator services.

For complete technical data, dimensional drawings, and product configurator access, visit the ROSS Controls MD4 Series product page or contact ROSS Controls directly.

Download Catalog: https://www.rosscontrols.com/en/series/75-md4-series