Shand & Jurs Model 9431X Series Detonation Flame Arresters

The 9431X Series Detonation Flame Arresters are designed for tank farm safety engineers, HSE and compliance managers, marine terminal operations leaders, and EPC project specifiers who need certified protection in piping systems where flame acceleration can transition from deflagration to detonation.

Installed within vapor recovery lines and long piping runs, the arrester stops a supersonic flame front before it reaches storage tanks or process equipment, protecting against catastrophic failure modes that deflagration arresters are not intended to address.

A 316 stainless steel tube bank absorbs heat and dissipates pressure energy from the combustion wave, while the reinforced housing withstands instantaneous pressures exceeding 500 psig with flame approach from either direction.

Welded to ASME Section VIII and IX, the series is available in 2–24 in. sizes with ANSI Class 150 or 300 flanges, and supports NEC Group D or C&D gases with Factory Mutual and USCG marine approvals, depending on model.

Applications

Vapor Recovery Headers and Long Piping Runs: Installed in vapor recovery headers and extended piping runs where flame acceleration to detonation is credible, protecting upstream tanks and process equipment from a supersonic flame front.
Marine Loading Lines and Terminal Piping: USCG-approved variants support flame protection on marine loading arms, dock piping, and vapor return lines where regulatory compliance for vessel-to-shore transfer is required.
Tank Interconnections and Process Vapor Systems: Applied at tank interconnections, manifold headers, and process vapor piping where confined runs can support flame transition from deflagration to detonation.
Digester Gas and Biogas Distribution Piping: Protects digester gas and biogas distribution piping from detonation propagation while maintaining the flow characteristics required for normal vapor movement.

Technical Specifications

Parameter

Specification

Series

Shand & Jurs® 9431X Series Detonation Flame Arresters

Included Models

94311, 94312, 94313, 94314

Technology

Detonation-rated 316 stainless steel tube bank flame arrester

Size Range

2 in. to 24 in.

Flame Type

Detonation (supersonic flame front)

Protection Direction

Bidirectional — flame approach from either direction

Max Instantaneous Pressure

> 500 psig

Hydrostatic Test Pressure

Class 150 at 425 psig; Class 300 at 750 psig

Gas Groups

NEC Group D (94311, 94312); NEC Groups C & D (94313, 94314)

Approvals

Factory Mutual (FM) and USCG marine approvals — model dependent

Construction Standard

Welded in accordance with ASME Section VIII and IX

Installation

Inline piping

Flange Options

ANSI Class 150 or Class 300; EN 1092-1 metric drilling available

Body and Seat

Carbon Steel or 316 Stainless Steel

Tube Bank and Shell

316 Stainless Steel

Hardware

316 Stainless Steel

Material Options

Duplex stainless for severe corrosion environments

Accessory Ports

Optional pressure and temperature instrumentation taps; drain plug

Typical Applications

Vapor recovery headers, long piping runs, marine loading lines, process vapor systems, digester gas piping, tank interconnections.

2026 COST ESTIMATE

Support

If you have questions not covered here, please contact the Cognesense support team for assistance.

When should I specify a detonation arrester instead of a deflagration arrester?

−

Detonation protection is required where piping length and confinement allow flame acceleration to transition from subsonic deflagration to a supersonic detonation. In those conditions, a deflagration arrester is under-specified. For confined piping where detonation cannot develop, the Shand & Jurs 9440X Inline Deflagration Series is the appropriate option.

How does the Model 9431X Series stop a detonation wave?

The 316 stainless steel tube bank absorbs heat and dissipates pressure energy from the approaching combustion wave, quenching the flame while maintaining element and housing integrity. The reinforced construction is designed to withstand instantaneous flame-front pressures exceeding 500 psig.

Is the arrester bidirectional?

Yes. The 9431X Series provides bidirectional protection, so ignition can approach from either side of the arrester. This eliminates the need to predict the ignition source location when specifying protection for interconnected piping or vapor recovery headers.

Which models carry marine and FM approvals?

Factory Mutual and USCG approvals vary by model. The 94311 and 94312 cover NEC Group D service, while the 94313 and 94314 extend coverage to NEC Groups C and D. Confirm the specific approvals required for your installation against the model selection and the latest certification documents.

What pressure class and material options are available?

The series is available with ANSI Class 150 or Class 300 flanges — hydrostatically tested at 425 psig and 750 psig respectively — plus EN 1092-1 metric drilling. Body and seat can be carbon steel or 316 stainless steel, with duplex stainless available for severe corrosion environments. Tube bank, shell, and hardware are 316 stainless steel.