Shutdown valve symbol

Also called SDV, ESDV, Emergency shutdown valve

A shutdown valve closes automatically to isolate a section of plant when the safety system trips. It is on/off only and is designed to fail to its safe position.

Shutdown valve P&ID symbol
Shutdown valve symbol, as drawn on a P&ID

What the shutdown valve symbol means

A shutdown valve closes automatically to isolate a section of plant when the safety system trips. It is on/off only and is designed to fail to its safe position.

How it is drawn

A ball or gate valve body with an actuator on top, a solenoid or a piston, and an S or ESD marking. Its tag bubble connects to the safety instrumented system.

The shutdown valve symbol in each standard

ISA 5.1

Drawn as ISA 5.1 defines it, as on most US and international legends.

Not in ISO 10628-2
ISO 10628-2

ISO 10628-2 does not draw actuators. Actuators come from ISO 14617-4, and how a valve is controlled is shown with the instrumentation, usually to IEC 62424.

German (DIN): Schnellschlussarmatur. See DIN P&ID symbols.

Where you see it on a P&ID

At unit boundaries, on wells, on vessel inlets and outlets, and on fuel supplies.

Tag codes

The shutdown valve is commonly tagged:

  • XV
  • SDV
  • ESDV
  • BDV (blowdown)

Tag formats follow the project numbering procedure. For instruments, the letters follow ISA 5.1, explained on the instrument symbols page.

Frequently asked questions

What does the shutdown valve symbol look like on a P&ID?

A ball or gate valve body with an actuator on top, a solenoid or a piston, and an S or ESD marking. Its tag bubble connects to the safety instrumented system.

What is a shutdown valve used for?

A shutdown valve closes automatically to isolate a section of plant when the safety system trips. It is on/off only and is designed to fail to its safe position. You will find it at unit boundaries, on wells, on vessel inlets and outlets, and on fuel supplies.

What tag does a shutdown valve have?

It is commonly tagged XV, SDV, ESDV, BDV (blowdown). The exact tag format comes from the project numbering procedure and the legend sheets.

Is the shutdown valve symbol the same in ISA and ISO?

ISO 10628-2 does not draw actuators. Actuators come from ISO 14617-4, and how a valve is controlled is shown with the instrumentation, usually to IEC 62424. Companies vary the details, so always check the legend sheets at the front of the P&ID set.

What is the shutdown valve called in German?

Schnellschlussarmatur. On a German R&I-Fließschema it is drawn to DIN EN ISO 10628-2.

Every shutdown valve on your drawings, found for you.Deskely Extract reads ISA and ISO P&IDs alike, finds each tag with its type, system and subsystem, and hands your engineers a register to check instead of a spreadsheet to type.
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