Full-Size Precision Series Port Sizes 1/4" to 3/4"; Flow to 155 scfm (4490 l/min)

Product Overview

The ROSS Controls is a family of full-size modular precision pressure regulators designed for industrial applications requiring accurate, repeatable outlet pressure control with flow capacities up to 155 scfm (4490 l/min). Available in 1/4", 3/8", 1/2", and 3/4" port sizes, the series accepts inlet supply pressures up to 300 psig (21 bar) and provides regulated outlet pressures from 15 to 250 psig (1 to 17 bar), with a standard range of 15 to 200 psig (1 to 13.8 bar).

The Series employs diaphragm construction with internal pilot design, a configuration that provides improved torque control for pneumatic tools by isolating the regulator's sensing from downstream pressure fluctuations caused by tool actuation. This internal pilot arrangement, combined with a large diaphragm sensing area and small valve seat geometry, holds pressure settings within 3 psig (0.2 bar) over a wide range of flow demand - a performance level that directly translates to consistent torque output on assembly lines.

As a modular regulator, the series is designed for integration into ROSS FRL manifold assemblies, allowing direct connection to modular filters, lubricators, and other preparation equipment without intervening pipe fittings. This modular capability enables compact FRL station construction with minimum pressure drop across connections and simplified maintenance through individual module replacement.

The self-relieving design ensures that downstream pressure bleeds back through the regulator body whenever the set point is adjusted downward, preventing pressure build-up above the new set point and eliminating the need for separate downstream relief devices in most pneumatic circuits. Both NPTF and G (BSPP) thread standards are available, and front and rear 1/4" NPT gauge ports allow pressure monitoring in either direction.

Key Engineering Features

• Internal Pilot Diaphragm Design - Precision internal pilot arrangement isolates downstream pressure fluctuations from the sensing element, enabling pressure settings held within 3 psig (0.2 bar) and improved torque control for pneumatic tools across all flow conditions.
• Modular Mounting Compatibility - Designed for direct integration into ROSS FRL modular manifold assemblies, enabling compact filter-regulator-lubricator combinations without pipe fittings between modules.
• Self-Relieving Design - Automatically vents downstream pressure through the regulator body when set point is reduced, simplifying circuit design by eliminating separate downstream relief valves in most applications.
• High Flow Capacity - Delivers up to 155 scfm (4490 l/min) through 3/4" port configurations, supporting high-demand multi-tool stations and central FRL supply points.
• Wide Pressure Range - Standard range covers 15 to 200 psig (1 to 13.8 bar) outlet; optional spring extends to 15 to 250 psig (1 to 17 bar), accommodating high-pressure tool and process requirements.
• High Inlet Pressure Rating - Accepts inlet supply pressures up to 300 psig (21 bar), accommodating high-pressure headers and compressed gas systems while delivering precise working pressure downstream.
• Dual Gauge Port Orientation - Front and rear 1/4" NPT gauge ports allow pressure gauge installation in either orientation, with options for 0 to 200 psig (0 to 14 bar) gauges as accessories.
• Panel Mount Capability - Accepts panel mounting through a 2-1/16" (52 mm) cutout for flush installation in control panels and operator stations.
• NPTF and G Thread Options - Available in both NPTF and G (BSPP) thread standards for worldwide pneumatic system compatibility.
• Zinc Body Construction - Die-cast zinc body with nylon dome (aluminum dome available with higher-pressure spring) and acetal knob provides durability in industrial environments.

Technical Specifications

General Specifications

Temperature Ratings

Temperature limits apply to both ambient environment and compressed air media.

Flow Performance Data

Flow performance measured at 100 psig (6.9 bar) inlet. Flow capacity varies with port size; 155 scfm is the maximum at 3/4" port size.

Certifications & Compliance

Typical Applications & Industries

Automotive and Assembly Manufacturing

• Precision air supply for pneumatic torque tools (nutrunners, pulse tools, torque wrenches) at assembly stations, where the 3 psig pressure accuracy band directly limits torque variation and ensures fastener joint quality.
• Multi-spindle assembly cell FRL station supply regulation for production lines running multiple concurrent tools from a single regulated circuit, requiring consistent pressure across variable aggregate demand.
• Robot end-of-arm tool supply regulation for pneumatic grippers, suction cups, and pneumatic actuators on robotic assembly and material handling equipment.
• Engine and transmission assembly line supply conditioning for sensitive leak and flow test fixtures requiring stable reference pressures to distinguish acceptable from defective parts.
• Body shop paint application equipment supply regulation for pneumatic actuators controlling spray gun positioning and part fixturing in automated painting cells.

General Manufacturing and Fabrication

• Precision clamp and fixture supply for pneumatic workholding on CNC machining centers, where consistent clamping force ensures part positioning repeatability and surface finish quality.
• Stamping and forming press cushion supply regulation where air pressure controls the die cushion force in metal stamping operations, directly affecting part draw depth and springback.
• Spray coating and lubrication system supply regulation for controlled atomization pressure in lubricant application, adhesive dispensing, and part cleaning stations.
• Plastic blow molding and thermoforming process air supply regulation where consistent forming pressure determines part wall thickness uniformity.
• Palletizer and packaging line actuator supply regulation for consistent cycle times and throughput on high-speed automated packaging equipment.

Modular FRL Station Integration

• Central compressed air supply preparation station combining Series precision regulator with upstream filtration and downstream lubrication in a modular manifold assembly, serving multiple downstream pneumatic circuits from a common service point.
• Zone pressure control in large facilities where building-wide supply cannot be regulated to precision levels; zone regulators at point-of-use provide the required accuracy.
• Redundant FRL station construction using two Series units in parallel with isolation valves, allowing one unit to be serviced without interrupting production.
• Machine tool pneumatic circuit supply conditioning for air bearings, tool changers, and drawbar actuation on high-precision machining equipment.

Pneumatic Control Systems

• Pilot supply conditioning for pneumatic directional control valves requiring stable supply pressure to ensure consistent valve response time and consistent actuator speed.
• Differential pressure instrumentation supply regulation where supply stability is critical to measurement accuracy.
• Positioner supply regulation for pneumatically actuated process control valves where precise supply pressure ensures proper actuator sizing and valve authority.
• Pneumatic press brake and shear actuator supply regulation where consistent pressure produces consistent force and stroke speed for sheet metal fabrication quality.

Ordering and Model Number Configuration

The ROSS uses model numbers based on port size and pressure range. Two standard pressure ranges are offered: 15-200 psig (1-13.8 bar) and 15-250 psig (1-17.2 bar). G (BSPP) thread models are prefixed with C.

Standard pressure range: 15 to 200 psig (1 to 13.8 bar). Optional higher range: 15 to 250 psig (1 to 17.2 bar) - specify model 5214 series for higher range.

Dome removal clearance requires adding 0.63" (16 mm) to dimension B. Cap removal clearance requires adding 0.5" (13 mm) to dimension C. Account for these dimensions in space planning.

G (BSPP) thread models are identified by prefix C (e.g., C5213C2018). Verify thread standard before ordering.

Non-relieving option available for applications where downstream pressure must be maintained when regulator set point is raised. Consult ROSS Controls for non-relieving model configuration.

Pressure gauge (0-200 psig) and panel mount nut are available as accessories. Gauge ports are 1/4" NPT front and rear.

Standard Model Numbers - 15-200 psig Range

Standard Model Numbers - 15-250 psig Range

Accessories

Pressure Gauges

ROSS Controls offers 0 to 200 psig (0 to 14 bar) pressure gauges compatible with the 1/4" NPT gauge ports on the series. Front and rear port locations allow gauge installation in the most accessible orientation for the installation layout.

Panel Mount Nut

Panel mount nut for flush mounting the series through a 2-1/16" (52 mm) panel cutout. Required for control panel installations where the regulator must be fixed and accessible from the front of the panel.

Modular FRL Components

The Series is designed for modular connection with ROSS Controls filters, lubricators, and other FRL components. Modular manifold assemblies combine multiple units into compact service stations.

Related Products & Accessories

• 120 Series Miniature Precision Regulator - Inline precision regulator for 1/8" and 1/4" port sizes, flow to 40 scfm, for compact and instrument air installations. https://www.rosscontrols.com/en/series/120-miniature-precision-series
• 122 Series MD4 Precision Regulator - Modular MD4-platform 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
• 123 Series High-Capacity Precision Regulator - Inline high-capacity precision regulator for 3/4" to 1-1/2" ports, flow to 800 scfm, for central supply regulation. https://www.rosscontrols.com/en/series/123-high-capacity-precision-series
• 124 Series Full-Size Remote Pilot Regulator - Full-size modular remote pilot regulator sharing the same body platform as the series, adding remote pressure set point capability. https://www.rosscontrols.com/en/series/124-full-size-series-remote-pilot-reg
• ROSS FRL Filters (Full-Size Series) - Full-size modular filters for upstream air preparation, removing particulates before the precision regulator. https://www.rosscontrols.com/en/categories/filters
• ROSS FRL Lubricators (Full-Size Series) - Full-size modular lubricators for downstream oil-mist introduction to tool supply circuits following the precision regulator. https://www.rosscontrols.com/en/categories/lubricators

Frequently Asked Questions (FAQ)

Q: What is an internal pilot regulator and how does it differ from a standard regulator?

A: An internal pilot regulator uses a small auxiliary pilot circuit to sense downstream pressure and control the main valve. This isolates the sensing element from the full downstream pressure dynamics, resulting in tighter regulation with less droop across varying flow demand. The Series holds pressure within 3 psig (0.2 bar) - a level of accuracy that directly improves torque tool repeatability.

Q: What is the maximum flow capacity of the series?

A: The Series provides flow up to 155 scfm (4490 l/min) at 3/4" port size. Flow capacity varies with port size, ranging from approximately 55 scfm at 1/4" up to 155 scfm at 3/4". For higher flow precision regulation, the 123 Series (800 scfm) with larger port sizes should be evaluated.

Q: Can the series be used in modular FRL assemblies?

A: Yes. The Series is specifically designed for modular mounting with ROSS Controls FRL components including filters and lubricators. Modular connections eliminate intervening pipe fittings, reduce pressure drop, and create compact, easily serviced FRL stations.

Q: What pressure ranges are available?

A: The standard range is 15 to 200 psig (1 to 13.8 bar) for model 5213 series. An extended range of 15 to 250 psig (1 to 17.2 bar) is available with the 5214 model series, which uses a different internal spring and an aluminum dome instead of nylon.

Q: What is the maximum inlet supply pressure?

A: The Series accepts inlet supply pressures up to 300 psig (21 bar). This accommodates high-pressure header systems and high-pressure gas cylinders while delivering regulated working pressure within the 15 to 250 psig outlet range.

Q: Is a non-relieving option available?

A: Yes. While the standard Series is self-relieving, a non-relieving option is available for applications where downstream pressure must be maintained when inlet pressure drops below set point. Contact ROSS Controls for non-relieving model configurations.

Q: How does the series mount in a control panel?

A: Panel mounting is accomplished through a 2-1/16" (52 mm) diameter cutout using an optional panel mount nut. The regulator body depth of 2.8" (71 mm) without gauge must be accommodated behind the panel. Dome removal requires an additional 0.63" (16 mm) of clearance above the mounted unit.

Q: What are the gauge port specifications?

A: The Series has 1/4" NPT gauge ports located both front and rear. Compatible gauges read 0 to 200 psig (0 to 14 bar). Always plug the unused gauge port with a 1/4" NPT plug when a gauge is installed in one port only.

Q: What thread standards are available?

A: NPTF (American National Taper Pipe Thread, dryseal) is standard. G (BSPP, ISO 228-1) thread models are available and identified by the prefix C in the model number. Verify the required thread standard before ordering to avoid thread incompatibility with existing piping.

Q: Can the adjusting knob be removed for tamper resistance?

A: Yes. The adjusting knob is removable and can be withdrawn after setting the desired pressure to provide tamper resistance in production environments. Retain the knob for future set point adjustments.

Q: What filtration level is required upstream?

A: A minimum of 5-micron particulate filtration is recommended upstream of the series to protect the valve seat and diaphragm. ROSS Controls modular filters designed for the full-size FRL platform connect directly to the series without fittings.

Q: What is the operating temperature range?

A: The Series with standard Nitrile seals operates from 40 F to 125 F (4 C to 52 C) for both ambient and media temperatures. This covers standard indoor industrial environments. Higher-temperature applications should be reviewed with ROSS Controls engineering.

Installation & Maintenance Guidelines

• Install a minimum 5-micron upstream particulate filter to protect the precision regulator valve seat and diaphragm from contamination.
• Mount in any orientation; however, vertical mounting with the gauge port accessible is recommended for optimum serviceability.
• For modular installation, follow ROSS Controls modular manifold assembly procedures to ensure proper port alignment and sealing between modules.
• Ensure inlet supply pressure does not exceed 300 psig (21 bar) maximum. Exceeding this limit may damage the diaphragm and internal sealing components.
• Set the desired outlet pressure by turning the adjusting knob clockwise to increase and counterclockwise to decrease. Verify with a calibrated gauge at the downstream gauge port.
• Do not exceed 250 psig (17 bar) outlet pressure even when using the extended-range spring option. Operating beyond rated pressure limits reduces regulator service life.
• For panel mounting, use a 2-1/16" (52 mm) diameter cutout and secure with the optional panel mount nut. Allow 0.63" (16 mm) dome removal clearance above the mounted unit.
• Plug the unused 1/4" NPT gauge port when only one gauge is installed. An open gauge port will result in uncontrolled air release at regulated pressure.
• Verify ambient operating temperature remains within 40 to 125 F (4 to 52 C). Temperatures outside this range degrade diaphragm performance and seal integrity.
• After installation, perform a full operating cycle test: increase set pressure to maximum, verify output, reduce to minimum, verify self-relieving action and downstream pressure drop.

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 support for the series is available through ROSS Controls USA at (800) 438-7677, with global support through ROSS offices in Canada, Brazil, Germany, France, United Kingdom, India, China, and Japan.

Replacement parts, seal kits, and service documentation for the series are available through ROSS Controls and its authorized distributor network.

Visit rosscontrols.com for product configuration tools, technical data downloads, dimensional drawings, and distributor locator services.

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