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Medium – Low Pressure Gas Regulators

Reliable pressure regulation for medium to low pressure gas distribution networks.

This page lists Pietro Fiorentini medium pressure gas regulators for district stations, distribution networks, commercial users and small and medium industry. Most models are classified under EN 334.

Pilot operated and direct operated designs, also known as gas pressure reducing valves or PRVs, cover inlet pressure up to 25 bar, outlet settings from 5 mbar to 12 bar and sizes 1 to 10 inches, supplied and supported from Al Khobar for gas networks and industry in Saudi Arabia and the GCC: the UAE, Qatar, Kuwait, Bahrain and Oman.

Pilot Operated

Aperval pilot operated medium pressure gas regulator, flanged body with pilot, fail open, by Pietro Fiorentini H2 Ready
Pilot Operated

Aperval

Pilot operated regulator for medium-low pressure gas distribution applications.

  • Design Pressure: Up to 25 bar
  • Sizes: 1″ - 4″
  • Classification: Fail Open (EN 334)
  • Connections: 150 RF, PN 16, PN 25
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Aperval 101 pilot operated medium-low pressure gas regulator, flanged body with pilot, by Pietro Fiorentini H2 Ready
Pilot Operated

Aperval 101

Pilot operated regulator for medium-low pressure gas distribution networks.

  • Design Pressure: Up to 18.9 bar
  • Sizes: 2″ - 4″
  • Classification: Fail Open (EN 334)
  • Connections: 125 FF, 125 RF, 150 RF, PN 16
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Dixi pilot operated medium-low pressure gas regulator, flanged body with pilot, by Pietro Fiorentini H2 Ready
Pilot Operated

Dixi

Pilot operated regulator for medium-low pressure gas distribution applications.

  • Design Pressure: Up to 16 bar
  • Sizes: 1″ - 2″
  • Classification: Fail Close / Fail Open (EN 334)
  • Connections: 150 RF, PN 16, PN 25
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Reval 182 pilot operated gas pressure regulator for distribution networks, flanged, by Pietro Fiorentini H2 Ready
Pilot Operated

Reval 182

Pilot operated regulator for medium-low pressure gas applications.

  • Design Pressure: Up to 25 bar
  • Sizes: 1″ - 10″
  • Classification: Fail Close / Fail Open (EN 334)
  • Connections: 150 RF or RTJ, PN 16/25/40
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Terval/A pilot operated gas regulator with monitor and slam shut on one body by Pietro Fiorentini H2 Ready
Pilot Operated

Terval/A

Pilot operated regulator for medium-low pressure gas distribution.

  • Design Pressure: Up to 25 bar
  • Sizes: 2″ - 4″
  • Classification: Fail Open (EN 334)
  • Connections: 150 RF or RTJ, PN 25/40
View Details
Terval/R fail close pilot operated gas regulator with monitor and slam shut on one body by Pietro Fiorentini H2 Ready
Pilot Operated

Terval/R

Pilot operated regulator for medium-low pressure gas applications.

  • Design Pressure: Up to 25 bar
  • Sizes: 2″ - 4″
  • Classification: Fail Close (EN 334)
  • Connections: 150 RF or RTJ, PN 25/40
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Direct Operated

Cirval lever operated medium-low pressure gas regulator, fail open, by Pietro Fiorentini H2 Ready
Direct Operated

Cirval

Direct operated regulator for medium-low pressure gas distribution.

  • Design Pressure: Up to 8.6 bar
  • Sizes: 1-1/4″ - 2″
  • Classification: Fail Open (EN 334)
  • Connections: Threaded NPT, ANSI 125 FF
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Cirval CE lever operated medium-low pressure gas regulator, fail open (EN 334), by Pietro Fiorentini H2 Ready
Direct Operated

Cirval CE

CE certified direct operated regulator for medium-low pressure applications.

  • Design Pressure: Up to 8.6 bar
  • Sizes: 1-1/2″ - 2″
  • Classification: Fail Open (EN 334)
  • Connections: Threaded ISO 228-1, PN 16, ANSI 150RF
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Dival 500 direct operated medium-low pressure gas regulator, 1 inch threaded body, by Pietro Fiorentini H2 Ready
Direct Operated

Dival 500

Direct operated regulator for medium-low pressure gas distribution.

  • Design Pressure: Up to 20 bar
  • Sizes: 1″ x 1″, 1″ x 1-1/2″
  • Classification: Fail Open (EN 334)
  • Connections: Rp, NPT
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Dival 507-512 direct operated gas pressure regulator, threaded body, by Pietro Fiorentini H2 Ready
Direct Operated

Dival 507-512

Direct operated regulator series for medium-low pressure applications.

  • Design Pressure: Up to 20 bar
  • Sizes: 1″ - 1-1/2″
  • Classification: Fail Open (EN 334)
  • Connections: Threaded Rp, NPT
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Dival 600 direct operated gas pressure regulator, flanged, by Pietro Fiorentini H2 Ready
Direct Operated

Dival 600

Direct operated regulator for medium-low pressure gas distribution.

  • Design Pressure: Up to 20 bar
  • Sizes: 1″ - 2″
  • Classification: Fail Open (EN 334)
  • Connections: 150 RF, PN 16, PN 25
View Details
Dival 700 direct operated low pressure gas regulator, flanged, by Pietro Fiorentini H2 Ready
Direct Operated

Dival 700

Direct operated regulator for medium-low pressure gas applications.

  • Design Pressure: Up to 20 bar
  • Sizes: 1″ - 2″
  • Classification: Fail Open (EN 334)
  • Connections: 150 RF, PN 16, PN 25
View Details
Dival SQD-1 direct operated gas regulator with built-in cartridge filter, 1½ inch flanged, by Pietro Fiorentini H2 Ready
Direct Operated

Dival SQD-1

Direct operated regulator for medium-low pressure distribution networks.

  • Design Pressure: Up to 6 bar
  • Sizes: 1½″
  • Classification: Fail Open (EN 334)
  • Connections: Class 150 RF, PN 16/25
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Dival SQD-2 direct operated gas regulator with built-in cartridge filter, 2 inch flanged, by Pietro Fiorentini H2 Ready
Direct Operated

Dival SQD-2

Direct operated regulator with diaphragm and spring control.

  • Design Pressure: Up to 6 bar
  • Sizes: 2″
  • Classification: Fail Open (EN 334)
  • Connections: Class 150 RF, PN 16/25
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Dival SQD-6 direct operated gas regulator with built-in cartridge filter, 2 inch inlet, 3 inch outlet, by Pietro Fiorentini H2 Ready
Direct Operated

Dival SQD-6

Direct operated regulator for filtered gaseous fluids in distribution networks.

  • Design Pressure: Up to 6 bar
  • Sizes: 2″ inlet, 3″ outlet
  • Classification: Fail Open (EN 334)
  • Connections: Class 150 RF, PN 16/25
View Details
Norval direct operated medium-low pressure gas regulator, flanged, fail open, by Pietro Fiorentini H2 Ready
Direct Operated

Norval

Direct operated regulator for medium-low pressure gas distribution.

  • Design Pressure: Up to 18.9 bar
  • Sizes: 1″ - 8″
  • Classification: Fail Open (EN 334)
  • Connections: 150 RF, PN 16
View Details
Trias direct operated medium-low pressure gas regulator, flanged, fail open, by Pietro Fiorentini H2 Ready
Direct Operated

Trias

Direct operated regulator for medium-low pressure gas applications.

  • Design Pressure: Up to 17 bar
  • Sizes: 1-1/2″ - 2″
  • Classification: Fail Open (EN 334)
  • Connections: 150 RF, PN 16
View Details

How to choose a medium pressure gas regulator

Start with three numbers: the inlet pressure range, the outlet set point and the flow at the lowest inlet pressure.

  • Cg and minimum differential

    Pietro Fiorentini brochures size each regulator with its flow coefficient Cg; check the minimum differential pressure too: Reval 182, Dixi and the Dival models work from 0.1 bar, while Aperval needs 0.45 bar.

  • Pilot operated models

    Pilot operated models suit larger flows and tighter control: Reval 182 covers 1 to 10 inches, inlet up to 25 bar and outlet from 7 mbar to 12 bar, with accuracy class up to 2.5.

  • Fail Open or Fail Close

    Aperval and Terval/A are Fail Open, Terval/R is Fail Close, and Dixi and Reval 182 can be either, depending on the pilot fitted.

  • Direct operated, spring loaded

    Simpler direct operated regulators fit smaller stations and end users: Dival 500 (1 inch threaded), Dival 600 (flanged 1 to 2 inch, outlet to 4.2 bar), Norval (1 to 8 inches, inlet to 18.9 bar).

  • Protection on the same body

    Many models accept an incorporated slam shut, a monitor or both: Terval/A and Terval/R carry an emergency monitor and a slam shut on the same body as the active regulator.

  • Trias versions, SQD filter

    Trias comes in pre-defined BM (monitor plus slam shut) and BB (double slam shut) versions; the Dival SQD models add a built-in replaceable cartridge filter.

  • What to send us

    For district stations in Riyadh or Dammam, or industrial users in Jubail and Doha, send us the gas data, pressures and flows, and our Al Khobar team will propose a model and configuration.

Most models are declared compatible with biomethane and with natural gas blended with 10 or 20 percent hydrogen, depending on the model.

Frequently asked questions

When is a direct operated regulator enough, and when do I need a pilot operated one?

A direct operated regulator, such as the Dival 500, Dival 600 or Norval, moves the valve with a diaphragm and spring. It is compact, simple to maintain and suits moderate flows. A pilot operated regulator, such as the Aperval, Reval 182 or Terval/R, uses a pilot to drive the main valve and handles larger flows with tighter accuracy, up to class 2.5 on Reval 182 and Dixi. Our guide on pilot operated vs direct operated regulators explains the trade-off.

Can a gas regulator have a built-in slam shut valve or monitor?

Yes. Most models on this page accept an incorporated slam shut, and several accept a monitor. Terval/A and Terval/R hold the active regulator, a PM/182 monitor and an SA slam shut on one body. Dival 500, Dival 600 and Dival 700 offer an LA slam shut and a monitor version. Norval takes an SN slam shut and an ER monitor attachment, and Trias BM combines a monitor and a slam shut.

How do I size a gas pressure regulator for flow and pressure drop?

Use the flow coefficient Cg given in each technical brochure. With Cg, the inlet pressure and the outlet pressure you can calculate the flow at full opening, or find the Cg needed for a given flow. Check the minimum differential pressure of the model, and allow for accessories: the brochures reduce Cg by 5% for an incorporated monitor and suggest 20% for an in-line monitor. Send us your data and we will check the selection.

What do Fail Open and Fail Close mean under EN 334?

EN 334 classifies how a regulator reacts if it fails. A Fail Open regulator reacts by opening, so a monitor or slam shut downstream must handle the pressure rise. A Fail Close regulator reacts by closing. On this page Aperval, Terval/A, Norval, Trias and the Dival models are Fail Open, Terval/R is Fail Close, and Dixi and Reval 182 are Fail Close or Fail Open depending on the pilot installed.

Do you supply these regulators across the GCC?

Yes. Pietro Fiorentini Saudi Industry in Al Khobar supplies and supports the regulators on this page for gas networks, district stations and industrial users in Saudi Arabia, the UAE, Qatar, Kuwait, Bahrain and Oman. Send us the gas type, inlet and outlet pressures, flow rate and the safety devices you need, and we will propose a model and prepare a quotation.

Need Help Selecting the Right Regulator?

Our technical team can help you choose the optimal medium-low pressure regulator for your application requirements.

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