High-Capacity Precision Series Port Sizes 3/4" thru 1-1/2"; Flow to 800 scfm (22656 l/min)

Product Overview

The ROSS Controls is a family of high-capacity inline precision pressure regulators designed for large-volume pneumatic systems requiring accurate, repeatable pressure control at flow rates up to 800 scfm (22656 l/min). Available in 3/4", 1", 1-1/4", and 1-1/2" port sizes, the series accepts inlet supply pressures up to 300 psig (21 bar) and delivers regulated outlet pressures from 15 to 250 psig (1 to 17 bar).

At the heart of the series is the same precision diaphragm mechanism found across the ROSS precision regulator family: a small valve seat working against a large diaphragm sensing area. This geometric relationship provides the high sensitivity to downstream pressure changes needed for precision regulation, holding set pressures within 3 psig (0.2 bar) even at the high flow rates typical of central supply stations and production main headers. The result is consistent working pressure delivered to multiple downstream circuits simultaneously without the significant pressure droop common in standard regulators at high flow demand.

The Series is designed as an inline regulator, making it the appropriate choice for central air supply stations, production main headers, and facility-level pressure conditioning where modular manifold mounting is not practical. The aluminum body provides corrosion resistance and reduced weight at the large port sizes, while the zinc dome and acetal bonnet components resist the corrosive oil-mist atmospheres typical near compressor and FRL rooms.

Extended temperature operation to 175 F (79 C) allows the series to be located in warmer areas of industrial facilities, including near furnaces, ovens, or in hot-weather outdoor installations, without requiring special seal options. Both NPTF and G (BSPP) thread standards are available across all port sizes.

Key Engineering Features

• Highest Flow Precision Regulation - Delivers flow up to 800 scfm (22656 l/min) through the 1-1/2" port configuration, making the series the highest-flow inline precision regulator in the ROSS FRL lineup, suitable for central supply headers and large production machines.
• Extended Temperature Range - Standard configuration operates to 175 F (79 C) ambient and media temperature, 50 F above the miniature and full-size precision series, enabling installation in warmer industrial locations without special seals or configurations.
• Precision Diaphragm Design - Small valve seat with large diaphragm sensing area holds regulated pressure within 3 psig (0.2 bar) at all flow conditions from zero demand to 800 scfm, providing consistent pressure for multi-circuit supply systems.
• Inline Installation - Direct inline pipe installation in 3/4" to 1-1/2" piping systems without requiring a separate manifold or modular mounting structure, making it the natural choice for central supply and header-level pressure regulation.
• High Inlet Pressure Rating - Accepts inlet supply pressures up to 300 psig (21 bar), accommodating high-pressure storage receivers and headers while delivering regulated precision working pressure to downstream systems.
• Two Standard Pressure Ranges - Available in 15-200 psig (1-13.8 bar) and 15-250 psig (1-17.2 bar) configurations for standard and high-pressure application requirements.
• Self-Relieving Design - Standard self-relieving design allows downstream pressure to vent through the regulator body on set point reduction, eliminating the need for separate downstream relief valves in most central supply configurations.
• Aluminum Body Construction - Aluminum body at 3/4" through 1-1/2" port sizes provides corrosion resistance and reduced weight compared to cast iron at large port sizes, facilitating installation in overhead or wall-mounted central supply locations.
• Large Gauge Ports - 1/4" NPT gauge ports front and rear for compatible pressure gauge installation; optional gauges reading 0 to 200 psig (0 to 14 bar) allow outlet pressure monitoring at the regulator body.
• NPTF and G Thread Standards - All port sizes available in both NPTF and G (BSPP) thread standards for compatibility with North American and international piping systems at large installation sizes.

Technical Specifications

General Specifications

Temperature Ratings

The Series is rated for higher temperature operation than the miniature and full-size precision series, with both ambient and media limits of 175 F (79 C), enabling installation in warmer areas of industrial facilities.

Flow Performance Data

Flow performance measured at 91 psig (6.3 bar) inlet pressure. Maximum 800 scfm is at 1-1/2" port size. Flow capacity is proportionally lower at smaller port sizes.

Certifications & Compliance

Typical Applications & Industries

Central Compressed Air Supply and Distribution

• Facility-level central supply precision regulators installed at the compressed air header entering a production area, reducing storage receiver pressure (often 150-200 psig) to the facility working pressure (typically 90-125 psig) with high flow capacity and tight pressure accuracy for all downstream zones.
• Main production machine supply regulation where a single large-bore precision regulator serves an entire machine's pneumatic system, ensuring consistent working pressure across all actuators and tools on that machine despite highly variable aggregate demand.
• Multi-machine zone supply regulation in manufacturing cells where one Series unit conditions supply for a group of machines operating at the same regulated pressure, with sufficient flow capacity to serve simultaneous peak demand.
• Compressor room outlet conditioning before distribution into facility headers, where consistent outlet pressure from the series prevents downstream actuator and tool performance variation caused by compressor pressure cycling.
• High-pressure gas cylinder manifold regulation for nitrogen, argon, or compressed air cylinders in industrial process and laboratory settings, reducing storage pressure to process working pressure at high flow rates.

Large Production Machinery

• Transfer line and flexible manufacturing system central air supply regulation serving dozens of actuators, cylinders, and pneumatic tools across the entire production line from a single Series unit.
• Press line supply regulation for pneumatic cushions, counterbalance systems, and die-change actuators on large stamping and forming presses, where the high flow capacity of the 1-1/2" Series accommodates rapid cushion refill demand.
• Injection molding machine air supply regulation for mold actuators, ejector systems, and core pulls, where the machine's high aggregate actuator demand requires a large-bore precision regulator at the machine's main air inlet.
• Industrial robot cell supply regulation for multi-robot installations where all robots in a cell are served from a common regulated supply point, requiring both high flow capacity and tight pressure accuracy for consistent robot performance.
• Paint booth and spray finishing line main supply regulation where atomization pressure uniformity across multiple spray guns or spindles requires a high-capacity precision regulator at the supply header.

Process Industries and Heavy Manufacturing

• Steel mill and metals processing compressed air supply regulation for rolling, forming, and heat treatment line pneumatic systems, where the extended 175 F (79 C) temperature rating allows installation in hot mill environments.
• Foundry and casting facility supply regulation for pneumatic sand handling, core blowing, and pattern actuator systems requiring high flow capacity and tolerance for elevated ambient temperatures.
• Chemical and petrochemical plant air supply regulation for instrument and utility air headers, where high flow precision regulation ensures consistent pilot air pressure for large valve positioners and actuated control valves.
• Paper mill and converting line supply regulation for pneumatic actuators, nip roll loading systems, and tension control devices in high-speed paper and packaging machinery.
• Mining and mineral processing supply regulation for large-bore pneumatic conveying, screening, and separation equipment requiring high flow precision air at process working pressures.

Aerospace and Defense Manufacturing

• Large aircraft assembly jig and fixture supply regulation providing consistent, precision air pressure to hundreds of pneumatic clamps, riveting tools, and assembly actuators simultaneously on large airframe assembly fixtures.
• Aerospace structure test facility supply regulation for pneumatic load application systems and actuated test fixtures requiring traceable, documented regulated pressure at high flow rates.
• Defense system assembly line supply conditioning where high-volume pneumatic tool circuits require precision pressure maintained within 3 psig of set point across highly variable demand cycles.

Ordering and Model Number Configuration

The ROSS model numbers are structured by port size and pressure range. Two standard ranges are available: 15-200 psig and 15-250 psig. G thread models are prefixed with C.

Standard pressure range: 15 to 200 psig (1 to 13.8 bar) with model 5213 series. Extended range to 250 psig available with model 5214 series.

G (BSPP) thread models are identified by prefix C (e.g., C5213D5017). Verify required thread standard before ordering.

Gauge ports are 1/4" NPT front and rear; plug unused port when gauge is installed in one location only.

Panel mounting through a 1-3/16" (30 mm) cutout is available, though the series is primarily used in inline pipe installations at these large port sizes.

Contact ROSS Controls for special pressure ranges or application-specific configurations outside standard catalog offerings.

Standard Model Numbers

Accessories

Pressure Gauges

0 to 200 psig (0 to 14 bar) pressure gauges available for 1/4" NPT gauge ports on the series. Install in front or rear port as required by installation layout.

Upstream Particulate Filters

ROSS Controls high-capacity inline filters are available for upstream installation to provide 5-micron particulate protection for the series valve seat and diaphragm in large-bore central supply applications.

Related Products & Accessories

• 121 Series Full-Size Precision Regulator - Modular precision regulator for 1/4" to 3/4" ports, flow to 155 scfm, for lower-flow precision applications. https://www.rosscontrols.com/en/series/121-full-size-precision-series
• 122 Series MD4 Precision Regulator - MD4 modular precision regulator for 3/8" to 3/4" ports, flow to 170 scfm, for MD4 FRL manifold systems. https://www.rosscontrols.com/en/series/122-md4-precision-series
• 126 Series High-Capacity Remote Pilot Regulator - High-capacity inline remote pilot regulator for 3/4" to 2" ports, flow to 4000 scfm, for remote pressure set point adjustment. https://www.rosscontrols.com/en/series/126-high-capacity-series-remote-pilot-reg
• 120 Series Miniature Precision Regulator - Miniature inline precision regulator for 1/8" and 1/4" ports, flow to 40 scfm, for instrument and tool applications. https://www.rosscontrols.com/en/series/120-miniature-precision-series
• ROSS High-Capacity Filters - Large-bore inline filters for upstream particulate removal in high-flow central supply applications. https://www.rosscontrols.com/en/categories/filters
• ROSS High-Capacity Lubricators - Large-bore inline lubricators for oil-mist addition in high-flow tool supply circuits. https://www.rosscontrols.com/en/categories/lubricators

Frequently Asked Questions (FAQ)

Q: What applications require a high-capacity precision regulator like the series?

A: The Series is appropriate when both high flow capacity (above 155 scfm) and precision pressure accuracy (within 3 psig) are simultaneously required. Typical applications are central compressed air supply stations serving multiple circuits, main production machine headers, large-bore transfer line supplies, and any application where standard precision regulators are too small and standard high-capacity regulators lack the required accuracy.

Q: How does the series differ from the 121 Series?

A: The Series provides significantly higher flow (800 vs. 155 scfm maximum) through larger port sizes (3/4" to 1-1/2" vs. 1/4" to 3/4"), uses inline rather than modular mounting, and is rated for higher ambient temperature (175 F vs. 125 F). Both series maintain the same 3 psig pressure accuracy specification. Choose the 121 Series for modular FRL station integration at moderate flow, and the series for inline central supply or header-level regulation at high flow.

Q: What is the maximum flow the series provides?

A: The Series provides flow up to 800 scfm (22656 l/min) through the 1-1/2" port configuration. This is the highest flow capacity in the ROSS precision regulator family. For applications requiring flow above 800 scfm with precision accuracy requirements, consult ROSS Controls for application-specific solutions.

Q: What is the maximum inlet pressure rating?

A: The Series accepts inlet pressures up to 300 psig (21 bar), identical to the 120 and 121 Series. The outlet pressure range is 15 to 200 psig standard, or 15 to 250 psig with the extended-range model.

Q: What is the operating temperature range and how does it compare to other precision regulator series?

A: The Series operates from 40 F to 175 F (4 C to 79 C), which is 50 F higher than the 120, 121, and 122 Series (limited to 125 F). This extended temperature tolerance is built into the standard configuration without requiring special seal options, making the series suitable for hot mill environments, outdoor installations in warm climates, and locations near heat sources.

Q: Is the series designed for modular or inline installation?

A: The Series is designed for inline installation in 3/4" to 1-1/2" piping systems. It does not use modular manifold mounting. For modular FRL assemblies at 3/4" port size and below, the 121 Series (standard full-size platform) or 122 Series (MD4 platform) are appropriate.

Q: What pressure ranges are available?

A: Two standard pressure ranges: 15 to 200 psig (1 to 13.8 bar) with model 5213D series, and 15 to 250 psig (1 to 17.2 bar) with model 5214D series. The outlet pressure range specification should match the target working pressure for optimum spring sensitivity and regulation accuracy.

Q: How accurate is the pressure regulation at high flow rates?

A: The Series maintains pressure within 3 psig (0.2 bar) of set point across the full flow range from zero demand to maximum rated flow. This accuracy is achieved by the same small-seat, large-diaphragm sensing geometry used in all ROSS precision regulators, scaled appropriately for the larger flow path.

Q: What filtration is required upstream of the series?

A: A minimum 5-micron upstream filter is recommended to protect the precision valve seat. At the large port sizes of the series, ROSS Controls high-capacity inline filters should be used. Contact ROSS Controls for appropriate filter model selection matched to the series port size.

Q: Can the series be used for gases other than compressed air?

A: The Series is rated for compressed air service. Nitrogen and other inert dry gases may be compatible given the aluminum body and Nitrile seals, but this must be verified with ROSS Controls for each application, including confirming adequate material compatibility and system safety requirements.

Q: Are both NPTF and G thread options available at all port sizes?

A: Yes. NPTF and G (BSPP) thread options are available for all Series port sizes from 3/4" through 1-1/2". G thread models use the C prefix in the model number. Confirm the required thread standard for the installation piping system before ordering.

Q: What is the physical size of the series?

A: The 3/4" and 1" port models measure 4.4" x 4.6" x 2.4" (111 x 112 x 62 mm) and weigh 2.0 lb (0.91 kg) without gauge. The 1-1/4" and 1-1/2" port models measure 4.9" x 4.9" x 2.1" (124 x 125 x 54 mm) and weigh 2.38 lb (1.08 kg) without gauge. These dimensions must be accounted for in piping layout and support planning.

Installation & Maintenance Guidelines

• Install the series in an accessible location in the compressed air supply piping system where the set point can be adjusted and the pressure gauges can be read.
• Install a minimum 5-micron upstream particulate filter to protect the precision valve seat from contamination at the large port sizes where higher flow velocities can entrain particulate.
• Ensure inlet supply pressure does not exceed 300 psig (21 bar). Exceeding maximum inlet pressure can damage the diaphragm and valve seat assembly.
• Support the series independently in the piping system. Do not allow pipe weight and thermal expansion loads to bear on the regulator body connections.
• Install the regulator with the adjusting knob accessible for set point adjustment. Vertical installation with the dome up is preferred for optimum diaphragm performance.
• Set the desired outlet pressure by turning the adjusting knob clockwise to increase and counterclockwise to decrease. Verify with a calibrated gauge at the front or rear 1/4" NPT gauge port.
• Plug the unused gauge port with a 1/4" NPT plug when only one gauge is installed. At central supply pressures, an open gauge port represents a significant uncontrolled air release.
• Verify that system piping flow capacity (pipe ID, run length, fittings) is sufficient for the series maximum rated flow at the installation pipe size. Undersized piping reduces effective flow capacity regardless of regulator rating.
• Maintain ambient temperature within 40 to 175 F (4 to 79 C). The Series Nitrile seals are rated for this extended temperature range in standard configuration.
• Perform a commissioned pressure test at the installed location: verify outlet pressure at zero flow (no downstream demand) and at full downstream demand to confirm the 3 psig accuracy specification is met under actual system conditions.

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 and application engineering support for the series central supply applications is available through ROSS Controls USA at (800) 438-7677.

Global support is available through ROSS Controls offices in Canada, Brazil, Germany, France, United Kingdom, India, China, and Japan.

Visit rosscontrols.com for technical data, dimensional drawings, application notes, and distributor locator services for the series.

Download Catalog: https://www.rosscontrols.com/en/documents