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Slam Shut Valves

Safety devices that quickly stop the gas flow when the monitored pressure reaches a pre-set limit.

A slam shut valve (SSV), also called a safety shut-off valve, closes the gas line when downstream pressure rises above its over pressure shut-off (OPSO) setting.

It closes when pressure falls below its under pressure shut-off (UPSO) setting too. Seven models designed to EN 14382 cover design pressures from 16 bar (SCN) to 250 bar (SBC 187 and SBC Mini), 1 inch to 12 inch (HBC 975), for gas networks and industry in Saudi Arabia and the GCC: the UAE, Qatar, Kuwait, Bahrain and Oman.

Slam Shut Valves: products

Dilock slam shut valve (OPSO/UPSO) for medium and low pressure gas distribution by Pietro Fiorentini H2 Ready
Slam Shut Valve

Dilock

Slam shut valve for medium and low pressure gas distribution networks.

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HBC 975 top-entry slam shut valve for high pressure gas by Pietro Fiorentini
Slam Shut Valve

HBC 975

Slam shut valve for high-pressure transmission systems.

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SBC 187 slam shut valve for high pressure gas up to 250 bar by Pietro Fiorentini
Slam Shut Valve

SBC 187

Slam shut valve for high-pressure transmission systems and medium pressure distribution networks.

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SBC 782 slam shut valve (safety shut-off) for gas stations by Pietro Fiorentini
Slam Shut Valve

SBC 782

Slam shut valve for high-pressure transmission systems and medium pressure distribution networks.

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SBC Mini compact slam shut valve, for CNG trailers and high pressure gas, by Pietro Fiorentini
Slam Shut Valve

SBC Mini

Compact slam shut valve for high-pressure transmission systems and medium pressure distribution networks.

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SCN compact slam shut valve for gas distribution networks up to 16 bar and 8 inch by Pietro Fiorentini H2 Ready
Slam Shut Valve

SCN

Compact slam shut valve for medium and low pressure gas distribution networks.

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SSX 176 compact slam shut valve for gas transmission and distribution by Pietro Fiorentini
Slam Shut Valve

SSX 176

Compact slam shut valve for high-pressure transmission systems and medium pressure distribution networks.

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How to choose a slam shut valve

Start with the design pressure and the network, then match size and connections.

  • Medium/low pressure networks

    Distribution and district stations: Dilock (up to 20 bar, 1 to 2 inch) and SCN (up to 16 bar, 1 to 8 inch) cover OPSO settings from tens of mbar to about 5 bar.

  • High pressure transmission

    For high pressure transmission, city gates and compressor stations, the SSX 176, SBC 782 and HBC 975 are rated to 102 bar, with OPSO settings up to 90 barg.

  • Size and connections

    The compact SSX 176 covers 1 to 6 inch, the SBC 782 1 to 10 inch with Class 150 to 600 RF/RTJ or PN 16/25/40 flanges, and the HBC 975 4 to 12 inch.

  • 250 bar in 1 inch

    Choose the SBC 187 with ANSI 1500 flanges, or the SBC Mini, which also comes with threaded NPT ends and is mainly used on CNG trailers.

  • Accuracy class and functions

    High pressure models reach accuracy class AG 2.5 for OPSO and UPSO, the Dilock AG 5 for OPSO; limit switch and remote tripping options let the control room see valve position and close it remotely.

  • Gas and hydrogen

    The Dilock and SCN are compatible with biomethane and 20 percent hydrogen blending, and the SBC 782 has a dedicated 100 percent hydrogen version, the SBC 782 H.

  • What to send us

    Our Al Khobar team can size a slam shut valve for a city gate near Riyadh or a district station in Kuwait City.

All seven trip within one second and are reset by hand after the cause has been found.

Frequently asked questions

How does a slam shut valve work (OPSO and UPSO)?

A pressure-sensing device on the valve monitors the downstream pressure. If the pressure rises above the over pressure shut-off (OPSO) setting, or falls below the under pressure shut-off (UPSO) setting, the valve closes the line within one second. It can also be tripped by hand at the installation point or, with the remote tripping option, from a distant control point.

How is a slam shut valve reset after it trips?

Reset is manual on all Pietro Fiorentini models. After a trip, the operator first finds and solves the cause, then restores the valve to the open position at the installation point. This keeps a protective shutdown from being undone automatically. Most models also include an internal bypass and a push button for tripping tests.

Do I need a relief valve as well as a slam shut valve?

In most stations, yes. The slam shut valve is the final protection and stops the supply completely. A relief valve, such as the VS/AM 65 or VS/AM 58, vents small pressure rises caused by thermal expansion or pressure shocks, so short events can be handled without a full shutdown. See our relief valves for the full range.

What does EN 14382 cover?

EN 14382 is the European standard for gas safety shut-off devices. Pietro Fiorentini slam shut valves are designed to it, and most models are also certified to the Pressure Equipment Directive 2014/68/EU (PED). Leakage is bubble tight, better than class VIII to ANSI/FCI 70-3, and end-to-end dimensions follow EN 334 and EN 14382 on most models.

Related categories

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Complete PRMS engineered and commissioned from Al Khobar.

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