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

Product Overview

The ROSS Controls Full-Size Series is a family of modular diaphragm pressure regulators covering port sizes from 1/4" to 3/4" with a maximum flow capacity of 155 scfm (4390 l/min). The Full-Size body accommodates 3/4" ports while maintaining modular mounting compatibility with other Full-Size Series FRL components, providing a higher-flow path than the Mid-Size and MD3 Series when 3/4" port sizes are required.

The Series uses diaphragm construction exclusively, delivering high sensitivity to downstream pressure changes and fast pressure recovery under variable load. Maximum inlet pressure is 300 psig (21 bar) with outlet adjustable up to 175 psig (12 bar) using standard springs, or higher with optional adjusting springs.

The series offers comprehensive configuration options: three adjustment ranges covering 0 to 50 psig through 0 to 175 psig, reverse flow for downstream pressure release applications, knob or T-Handle adjustment, and a removable locking key for tamper resistance. Pressure gauge options range from 0 to 200 psig (0 to 14 bar) as standard, with 1/4 NPT gauge ports on front and rear for installation flexibility.

The zinc body and 40 to 175 degrees F (4 to 79 degrees C) ambient temperature rating make the series suitable for the same range of warm industrial environments as the MD3 Series. Panel mounting requires a 2-1/16 inch (52 mm) hole, compatible with MD3 and MD4 panel cutouts.

Key Engineering Features

• Port Sizes to 3/4" - Expands the modular regulator range to 3/4" port sizes, bridging the gap between the MD3 Series (1/2" max) and the High-Capacity Series (3/4" minimum).
• Diaphragm Construction - Provides high sensitivity and fast pressure response under variable downstream load, with pressure settings stable across a wide range of flow conditions.
• Maximum Flow 155 scfm (4390 l/min) - Highest flow capacity among the modular pressure regulators in the ROSS FRL line, supporting large actuators and multi-actuator circuits.
• Maximum Inlet Pressure 300 psig (21 bar) - Rated for high-pressure supply systems, with optional springs enabling outlet pressure up to 175 psig (12 bar) for demanding applications.
• Reverse Flow Option - Available for weld gun and downstream pressure release applications, providing regulated forward pressure and quick exhaust capability in a single body.
• Modular Mounting - Connects directly to Full-Size Series FRL filters and lubricators without additional fittings, forming compact integrated air preparation assemblies.
• Knob and T-Handle Adjustment - Standard knob for most applications; T-Handle for higher adjustment torque, glove-friendly operation, and high-spring-force set point changes.
• Removable Locking Key - Prevents unauthorized set point changes after commissioning. Key can be reinstalled when adjustment is required.
• Wide Temperature Range - Rated for 40 to 175 degrees F (4 to 79 degrees C) ambient, suitable for warmer industrial environments than the Bantam and Miniature Series.

Technical Specifications

General Specifications

Certifications & Compliance

Typical Applications & Industries

Welding and Metal Fabrication

• High-force resistance welding circuits requiring 3/4" port size for adequate air flow to maintain electrode force through extended weld sequences.
• Robotic MIG and TIG welding cell pneumatic circuits where modular Full-Size assemblies provide centralized air preparation with 3/4" supply.
• Large-bore pneumatic clamp and fixture circuits in heavy fabrication where 3/4" regulated supply supports high-force workholding.
• Weld gun reverse flow circuits using the series reverse flow option to provide both weld pressure regulation and inter-weld quick exhaust at 3/4" port sizes.

Automotive Assembly

• Body shop main air preparation stations using modular Full-Size filter-regulator-lubricator assemblies to supply multiple downstream circuits from a single regulated 3/4" source.
• Assembly line pneumatic tool supply risers requiring regulated 3/4" air at 100 to 175 psig for high-torque assembly tools.
• Transfer line pneumatic circuits supplying multiple simultaneous actuator operations at the high flow rates enabled by 3/4" port sizes.
• Paint booth actuator supply using the elevated ambient temperature rating of the Full-Size Series in heated paint curing environments.

Industrial Pneumatics

• Large-bore cylinder supply circuits where 155 scfm flow capacity prevents pressure drop during rapid actuator cycling.
• Pneumatic press and forming machine supply where 3/4" regulated air at higher pressures maintains consistent press force.
• Multi-actuator machine centers using modular Full-Size assemblies for centralized air preparation at each machining station.
• High-pressure pneumatic circuits requiring regulated outlet pressure from 125 to 175 psig using the appropriate spring option.

Oil and Gas and Process Industries

• Instrument air supply at process plant pneumatic panels requiring regulated 3/4" air at elevated pressures for pneumatic valve positioners.
• Actuator supply regulators in process plant environments where the 175 degrees F ambient temperature rating accommodates heat from process equipment.
• Modular FRL assemblies at remote pneumatic instrument air supply points, combining Full-Size filter and regulator in a single assembly.

Ordering and Model Number Configuration

Related Products & Accessories

• MD3 Series Pressure Regulators - Modular diaphragm regulators, port sizes 1/4" to 1/2", flow to 120 scfm, outlet to 200 psig. https://www.rosscontrols.com/en/series/115-md3-series
• MD4 Series Pressure Regulators - Modular diaphragm regulators, port sizes 3/8" to 3/4", flow to 220 scfm, highest flow modular regulator. https://www.rosscontrols.com/en/series/117-md4-series
• 118 High-Capacity Series Pressure Regulators - Inline piston regulators for high-flow applications at port sizes 3/4" to 1-1/2", flow to 800 scfm. https://www.rosscontrols.com/en/series/118-high-capacity-series
• ROSS FRL Filters Full-Size Series - Full-Size Series filters for modular assembly with Full-Size Series regulators. https://www.rosscontrols.com/en/categories/36-air-preparation-frls

Frequently Asked Questions (FAQ)

Q: What port sizes are available for the Full-Size Series?

A: The Full-Size Series is available in 1/4", 3/8", 1/2", and 3/4" port sizes in both NPTF and G (BSPP) thread forms.

Q: What is the maximum flow capacity?

A: The Full-Size Series has a maximum flow capacity of 155 scfm (4390 l/min), the highest flow rate of any modular regulator in the ROSS FRL line.

Q: How does the Full-Size Series differ from the MD3 Series?

A: The Full-Size Series adds 3/4" port sizes not available in the MD3 Series, and has a higher maximum flow (155 vs. 120 scfm). The MD3 Series has a higher maximum outlet pressure range (200 vs. 175 psig) and a configurable model number with more gauge and adjustment options. Select Full-Size when 3/4" ports are required; select MD3 when higher outlet pressure or configurable model numbering is the priority.

Q: What is the maximum inlet pressure?

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

Q: What outlet pressures can the Full-Size Series regulate to?

A: Standard models regulate up to 175 psig (12 bar) with the 0 to 175 psig spring. Optional adjusting springs are available for other ranges. Three standard ranges are offered: 0 to 50 psig, 0 to 125 psig, and 0 to 175 psig.

Q: Is the series self-relieving?

A: Yes. The Full-Size Series is self-relieving as standard, automatically exhausting excess downstream pressure when the set point is reduced. Non-relieving configurations are available by consulting ROSS Controls.

Q: What is the reverse flow option?

A: Reverse flow models provide regulated pressure in the forward direction and quick exhaust in the reverse direction, designed for weld gun circuits that require fast inter-weld pressure release. Available with knob or T-Handle adjustment at 0 to 125 psig pressure range.

Q: What adjustment types are available?

A: Knob and T-Handle adjustment options are available. The T-Handle provides more adjustment torque for high-spring-force set points and glove-friendly operation.

Q: Does the Full-Size include a pressure gauge?

A: Yes. 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.

Q: What panel mounting hole is required?

A: The Full-Size Series requires a 2-1/16 inch (52 mm) panel mounting hole, the same as the MD3 and MD4 Series.

Q: What body material is used?

A: The body is zinc. The dome is nylon, or aluminum with the optional 0 to 175 psig spring. The knob is acetal. Seals are nitrile.

Q: Are G (BSPP) thread models available?

A: Yes. G thread models are available by prefixing the model number with 'C' (e.g., C5211B5027 for a 3/4" G thread regulator at 0 to 125 psig).

Q: What is the ambient temperature range?

A: The Full-Size Series is rated for 40 to 175 degrees F (4 to 79 degrees C), accommodating warmer industrial environments.

Q: Can I mix Full-Size and MD3 Series modular components?

A: Full-Size and MD3 Series components share the same 2-1/16 inch (52 mm) panel mounting hole but have different modular interface dimensions. Consult ROSS Controls to confirm compatibility before mixing series components in a modular assembly.

Installation & Maintenance Guidelines

• Install the Full-Size Series with the inlet port connected to the supply side and the outlet connected to the downstream circuit. Do not reverse flow through a standard (non-reverse flow) model.
• For modular assemblies, align all Full-Size Series interface connections properly before pressurizing. Misaligned modular faces can cause leakage and cross-port contamination.
• Apply thread sealant only to male port connections. Avoid applying sealant to the first two threads to prevent contamination of internal valve components.
• For dome removal clearance, allow at least 0.63 inches (16 mm) above the top of the dome. For cap removal, allow at least 0.5 inches (13 mm) below the cap.
• Set the outlet pressure under no downstream load by rotating the adjustment knob or T-Handle clockwise to increase and counterclockwise to decrease pressure.
• Monitor the gauge during adjustment to confirm the outlet pressure reaches the desired set point before locking.
• Remove or secure the locking key after final set point confirmation.
• For reverse flow models, test both forward pressure regulation and reverse exhaust before placing the machine in service.
• Do not exceed 300 psig (21 bar) inlet pressure.
• For panel mounting, use a 2-1/16 inch (52 mm) hole and ensure the gauge is accessible from the maintenance position.
• Inspect all connections for leaks after initial pressurization using an appropriate leak detection method.
• Ensure upstream filtration protects the regulator from particulate contamination. The nitrile seals and brass valve seat are sensitive to hard particulate damage.

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, modular assembly documentation, and catalog downloads, visit the ROSS Controls Full-Size Series product page at rosscontrols.com or contact ROSS Controls directly.

Download Catalog: https://www.rosscontrols.com/en/series/116-full-size-series