High Capacity Series Port Sizes 3/4" to 1-1/2"; Flow to 800 scfm (16992 l/min)

Product Overview

The ROSS Controls High-Capacity Series is a family of inline piston pressure regulators covering port sizes from 3/4" to 1-1/2" with a maximum flow capacity of 800 scfm (22,656 l/min). The High-Capacity Series addresses applications where the flow requirements of the MD4 Series (220 scfm maximum) are insufficient, bridging the gap to very large compressed air circuits supplying multiple actuators, high-throughput pneumatic systems, or large-bore cylinder drives.

Piston construction is used throughout the series, maximizing air flow through the large port body. All models are self-relieving as standard. A reverse flow option is available in the 3/4" port size with either knob or T-Handle adjustment, providing simultaneous regulated forward pressure and quick exhaust for weld gun and downstream pressure release circuits.

The Series is an inline design rather than modular, connecting directly into the compressed air main line or branch circuits using threaded pipe connections. Both NPT (NPTF) and G (BSPP) thread forms are available for all port sizes, accommodating both North American and international pneumatic system standards.

Maximum inlet pressure is 300 psig (21 bar) with outlet adjustable up to 100 psig (7 bar) using standard models. An optional locking key prevents unauthorized set point changes after commissioning. Pressure gauge output is 0 to 200 psig (0 to 14 bar) with 1/4 NPT gauge ports on front and rear. The aluminum body and 40 to 175 degrees F (4 to 79 degrees C) ambient temperature rating provide durability in warm industrial environments.

Key Engineering Features

• Maximum Flow 800 scfm (22,656 l/min) - Highest flow capacity of any standard pressure regulator in the ROSS FRL line, more than three times the MD4 Series flow, for the largest pneumatic circuits.
• Port Sizes 3/4" to 1-1/2" - Covers large-bore pipe sizes common in compressed air main lines, distribution headers, and large pneumatic equipment supply branches.
• Piston Construction - Maximizes air flow through large-body regulators, providing high flow capacity with consistent self-relieving operation across the full port size range.
• Self-Relieving Standard - Automatically exhausts excess downstream pressure when the set point is reduced, eliminating the need for a separate relief valve in most installations.
• Reverse Flow Option (3/4" port) - Available at 3/4" port size with knob or T-Handle adjustment for weld gun and downstream pressure release circuits requiring quick inter-weld exhaust.
• Maximum Inlet Pressure 300 psig (21 bar) - Rated for high-pressure supply systems, consistent with the MD3, Full-Size, and MD4 Series in the ROSS modular FRL platform.
• Aluminum Body Construction - The aluminum body provides lighter weight and better resistance to atmospheric corrosion than zinc-bodied regulators for equivalent structural performance.
• Optional Locking Key - Removable key prevents unauthorized set point changes after commissioning, supporting tamper-resistant installations in shared or public-access environments.
• NPT and G Thread Options - Available in both NPTF and G (BSPP) thread forms for all port sizes, enabling use in North American and international compressed air systems.

Technical Specifications

General Specifications

Certifications & Compliance

Typical Applications & Industries

Compressed Air Distribution

• Compressed air main header pressure regulation at 1" to 1-1/2" supply pipe sizes, establishing zone pressure for entire plant sections or manufacturing cells.
• Sub-header regulation supplying multiple downstream branch circuits from a single 800 scfm capacity regulator installed in the main distribution header.
• Pressure zone establishment at facility air distribution manifolds, reducing system pressure from compressor output to the operating level required by production equipment.
• Outdoor compressor station pressure regulation where the 40 to 175 degrees F temperature rating accommodates ambient temperature variation.

Large Pneumatic Equipment

• Supply pressure regulation for large-bore pneumatic cylinders and actuators in presses, clamps, and transfer machinery requiring port sizes of 1" or larger.
• Pneumatic power pack feed circuits where regulated air at high flow rates drives hydraulic boosters, intensifiers, or pneumatic power cylinders.
• Large-format packaging machine pneumatic supply where 800 scfm capacity handles multiple simultaneous high-speed actuator operations.
• Blow molding machine main air supply regulation where 1" to 1-1/2" port sizes and high flow rates match the air demand of large-volume blow circuits.

Industrial Process

• Pneumatic instrument air supply risers in process plants where regulated pressure at 3/4" to 1-1/2" serves multiple downstream instrument controllers.
• Actuator supply regulation in process plant air distribution where the aluminum body and 175 degrees F rating accommodate elevated process ambient temperatures.
• Pneumatic conveying system air supply regulation where large port sizes and high flow rates match the demands of dense-phase and dilute-phase conveying systems.
• Food and beverage processing plant pneumatic supply where inline High-Capacity regulators maintain consistent regulated pressure across high-flow air circuits.

Automotive and Heavy Manufacturing

• Main air supply regulation at automotive body shop pneumatic distribution headers, supplying entire welding cells or assembly stations from a single 1" regulator.
• Engine test cell air supply regulation where 800 scfm flow capacity accommodates simultaneous actuator and instrumentation air demand during engine testing.
• Stamping press pneumatic circuit regulation at 1" to 1-1/2" supply sizes, maintaining consistent counterbalance and die cushion pressures across press strokes.
• Foundry and forge shop pneumatic regulation where the aluminum body resists atmospheric corrosion in high-temperature industrial environments.

Ordering and Model Number Configuration

Related Products & Accessories

• MD4 Series Pressure Regulators - Modular piston or diaphragm regulators, port sizes 3/8" to 3/4", flow to 220 scfm, for modular assembly applications. https://www.rosscontrols.com/en/series/117-md4-series
• 116 Full-Size Series Pressure Regulators - Modular diaphragm regulators, port sizes 1/4" to 3/4", flow to 155 scfm. https://www.rosscontrols.com/en/series/116-full-size-series
• 119 High-Pressure Series Pressure Regulators - Inline piston regulators for high-pressure applications, port sizes 1/8" to 3/8", inlet to 400 psig, outlet to 390 psig. https://www.rosscontrols.com/en/series/119-high-pressure-series
• ROSS FRL Filters High-Capacity Series - High-Capacity Series particulate filters for inline installation upstream of Series regulators. https://www.rosscontrols.com/en/categories/36-air-preparation-frls

Frequently Asked Questions (FAQ)

Q: What port sizes are available for the High-Capacity Series?

A: The High-Capacity Series is available in 3/4", 1", 1-1/4", and 1-1/2" port sizes in both NPTF and G (BSPP) thread forms.

Q: What is the maximum flow capacity?

A: The High-Capacity Series has a maximum flow capacity of 800 scfm (22,656 l/min), more than three times the flow capacity of the MD4 Series.

Q: Why is the series an inline design rather than modular?

A: At port sizes of 3/4" to 1-1/2", inline installation is the standard approach for main line and large-diameter branch circuit regulation. The inline design installs directly into the pipe run without modular interface hardware.

Q: What is the maximum inlet pressure?

A: The maximum inlet pressure is 300 psig (21 bar).

Q: What outlet pressures can the High-Capacity Series regulate to?

A: Standard models regulate up to 100 psig (7 bar) with the 0 to 100 psig spring. An optional 0 to 150 psig spring extends outlet pressure to 150 psig. Two standard pressure ranges are offered: 0 to 50 psig and 0 to 100 psig.

Q: Is the series self-relieving?

A: Yes. All High-Capacity Series regulators are self-relieving as standard, automatically exhausting excess downstream pressure when the set point is reduced.

Q: Is reverse flow available at all port sizes?

A: Yes. Reverse flow models are available at 3/4", 1", 1-1/4", and 1-1/2" port sizes with either knob or T-Handle adjustment at 0 to 100 psig pressure range.

Q: What body material is used?

A: The body is aluminum. The dome is nylon as standard, or aluminum with the optional 0 to 150 psig spring. The knob is acetal. Seals are nitrile.

Q: What gauge is included?

A: A pressure gauge rated 0 to 200 psig (0 to 14 bar) is included with each regulator, with 1/4 NPT gauge ports on both front and rear of the body.

Q: Are G (BSPP) thread models available?

A: Yes. G thread models are available for all port sizes by prefixing the standard model number with 'C' (e.g., C5211D6017 for a 1" G thread regulator at 0 to 100 psig).

Q: What is the ambient temperature range?

A: The High-Capacity Series is rated for 40 to 175 degrees F (4 to 79 degrees C), the same as the MD3, Full-Size, and MD4 Series.

Q: How does the optional locking key work?

A: The locking key, when installed, prevents rotation of the adjustment knob, securing the outlet pressure set point against unauthorized changes. Remove the key to permit adjustment, then reinstall to lock.

Q: Does the series require upstream filtration?

A: Yes. Filtered compressed air is required. Install an appropriate particulate filter upstream of the regulator to protect the nitrile seals and brass valve seat from contamination damage.

Installation & Maintenance Guidelines

• Install the High-Capacity Series inline in the compressed air circuit with the inlet port connected to the supply side and the outlet port connected to the downstream circuit. Arrow markings on the body indicate the correct flow direction.
• Apply thread sealant to male pipe thread connections only. Keep sealant away from the first two threads to prevent contamination of internal passages and downstream equipment.
• For dome removal during maintenance, allow at least 0.63 inches (16 mm) of clearance above the dome top. For cap removal, allow at least 0.65 inches (16.5 mm) below the cap.
• Support the regulator body independently of the connected piping at 1-1/4" and 1-1/2" port sizes to prevent stress on the pipe connections during vibration.
• Set the outlet pressure by rotating the adjustment knob or T-Handle clockwise to increase and counterclockwise to decrease pressure. Monitor the gauge during adjustment.
• Install the optional locking key after final set point confirmation to prevent unauthorized adjustment.
• For reverse flow models, verify both regulated forward pressure and reverse exhaust functionality after installation and before placing the machine or circuit in service.
• Do not exceed 300 psig (21 bar) inlet pressure. Exceeding this rating risks body damage and loss of downstream pressure control.
• Inspect all pipe connections for leaks after initial pressurization using an appropriate leak detection solution.
• Ensure upstream air filtration is installed before the regulator. Large-port regulators serving entire plant sections should have appropriately sized particulate filters to protect internal valve components.
• Mount the regulator so the adjustment knob and gauge are accessible from the normal maintenance position. Consider lockout/tagout compliance when locating the regulator in areas with limited access.
• In installations near the rated maximum temperature of 175 degrees F (79 degrees C), confirm that the gauge and seals are rated for the application temperature.

Warranty & Global Support

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

Technical support is available through ROSS Controls USA at (800) 438-7677 or by visiting rosscontrols.com.

For product configuration, dimensional drawings, and catalog downloads, visit the ROSS Controls High-Capacity Series product page at rosscontrols.com or contact ROSS Controls directly.

Download Catalog: https://www.rosscontrols.com/en/series/118-high-capacity-series