Shand & Jurs Model 94406 Vertical Inline Deflagration Flame Arrester

The 94406 Vertical Inline Deflagration Flame Arrester is designed for tank farm safety engineers, HSE and compliance managers, process operations leaders, and EPC project specifiers who need certified inline flame protection for low-pressure vapor piping where ignition can occur downstream of the protected equipment.

A spiral-wound crimped ribbon tube bank absorbs heat from the flame front, dropping gas temperature below the ignition point and extinguishing combustion while maintaining high flow capacity and minimal pressure drop.

The vertical configuration supports installation above pressure-vacuum vents and within upright piping where condensate drainage is required. The removable tube bank allows inspection without removing the unit from the piping.

Designed to ISO 16852 and ATEX EN 12874 for IIA / NEC Group D service, the arrester is available in 2–12 in. sizes with ANSI or EN 1092-1 flanges. Sizing can be verified with Shand & Jurs WinSize against API 2000 venting requirements.

Applications

PVRV Discharge and Tank Vent Piping: Installed above pressure-vacuum relief vents and on tank vent headers to stop deflagration from traveling back into the tank vapor space while preserving venting capacity.
Digester Gas and Biogas Piping: Protects digester and biogas distribution piping where wet, low-pressure combustible vapor must move through upright runs without flashback risk, with vertical drainage supporting condensate handling.
Vapor Recovery Headers and Process Vent Manifolds: Applied in vapor recovery headers and process vent manifolds where a certified inline deflagration boundary is required to protect upstream tanks and equipment.
Flare Header Branches: Safeguards flare header branch connections from flame travel into connected process systems while maintaining the flow capacity needed for routine and upset vapor release.

Technical Specifications

Parameter

Specification

Model

Shand & Jurs® 94406 Vertical Inline Deflagration Flame Arrester

Technology

Spiral-wound crimped ribbon tube bank, vertical inline configuration

Size Range

2″, 3″, 4″, 6″, 8″, 10″, 12″

Max Static Pressure

3.45 barg (50 psig)

Operating Pressure

2–6″: 1.10 bara (16.20 psia); 8–12″: 1.09 bara (15.95 psia)

Max Operating Temperature

140 °F (60 °C)

Min Operating Temperature

−4 °F (−20 °C)

Gas Group

IIA / NEC Group D

Factory Approvals

Designed to ISO 16852 (Short Term Burn) and ATEX EN 12874

Installation

Vertical inline

Installation Run-Up

2–4″: 50 pipe diameters; 6″: 20 pipe diameters; 8–12″: 10 pipe diameters

Body Materials

Aluminum (ISO 16852 only, FF), Carbon Steel, or 316 Stainless Steel

Flame Element

Carbon Steel or 316 Stainless Steel tube bank

Hardware

316 Stainless Steel

Gaskets

High-temperature synthetic composition

Flange Options

ANSI 125/150 or EN 1092-1 PN10/16; FF or RF

Monitoring Ports

Optional differential pressure taps and temperature monitor connection

Sizing Support

Shand & Jurs WinSize software; API 2000 venting compatibility

Typical Applications

Inline vapor piping, PVRV discharge lines, digester gas piping, vapor recovery headers, process vent manifolds, flare header branches

2026 COST ESTIMATE

Support

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

When should I use the Model 94406 instead of an end-of-line or horizontal inline arrester?

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The Model 94406 is the correct choice for vertical inline installation in low-pressure vapor piping, including above PVRV outlets and within upright runs where condensate drainage is needed. For open vents, use the Shand & Jurs 9430X end-of-line series, and for horizontal inline installations use the Model 94407 Horizontal Series.

How does the Model 94406 stop a deflagration?

The spiral-wound crimped ribbon tube bank absorbs heat from the advancing flame front, dropping gas temperature below its ignition point and extinguishing combustion before it can propagate further. The element geometry holds pressure drop low so that venting capacity is preserved during normal operation.

What are the installation run-up distances to the ignition source?

Maximum run-up from the ignition source to the arrester is 50 pipe diameters for 2–4 in. sizes, 20 pipe diameters for 6 in., and 10 pipe diameters for 8–12 in. sizes. Observing these limits is critical to the certified deflagration-arresting performance of the unit.

Which certifications and gas groups does the Model 94406 cover?

The arrester is designed to ISO 16852 (Short Term Burn) and ATEX EN 12874 for IIA / NEC Group D gas groups. Aluminum body construction is approved for ISO 16852 only (FF flanges); carbon steel and 316 stainless steel bodies support both ISO 16852 and ATEX EN 12874 service.

How is element condition monitored in service?

Optional differential pressure taps allow measurement of pressure drop across the tube bank so inspection and cleaning intervals can be based on measured condition. A temperature monitor connection on the unprotected side supports condition-based maintenance and regulatory compliance monitoring.