Shand & Jurs 94126 Pressure Rim Vent

For floating-roof tank designers, petroleum terminal engineers, and specifying engineers, the Shand & Jurs 94126 Pressure Rim Vent provides low-pressure overpressure protection for floating-roof storage tanks and small low-pressure vessels.

Unlike conventional conservation vents intended for fixed-roof nozzles, the 94126 installs directly on the floating-roof rim and relieves excess vapor pressure that can develop between the floating roof and tank shell during rapid product movement, thermal expansion, or seal malfunction.

The vent remains closed during normal operation and opens when internal pressure exceeds the set threshold, preventing structural damage to roof pontoons, rim seals, and associated roof components. A weight-loaded pallet delivers repeatable opening without reliance on springs or complex mechanisms.

Supplied in a 6″ NPT connection and constructed in corrosion-resistant cast aluminum for exposed outdoor service, the 94126 uses a standard setting of 1/2 oz/in² (0.865 in. W.C.) with higher setpoints available up to 5.7 oz/in². ATEX and CE certified versions are available.

Features

Provides controlled opening at defined pressure without spring fatigue or calibration drift, delivering long-term mechanical stability on exposed floating-roof installations.

Supports low-pressure roof protection consistent with floating-roof design limits, matching typical rim-space allowable pressure across common petroleum storage configurations.

Higher relief thresholds accommodate specialized rim or auxiliary relief applications where floating-roof design permits elevated pressure tolerance between breathing events.

Corrosion-resistant construction suits exposed outdoor floating-roof environments where weather, humidity, and hydrocarbon vapor attack drive premature failure on uncoated steel.

Protects internal components from rain, snow, and debris intrusion, preserving pallet movement and sealing integrity during exposed outdoor service on floating roofs.

Standardized threaded connection simplifies installation and mounting to floating-roof rim assemblies, removing the need for flange-matching on floating-roof nozzle layouts.

Applications

Floating-Roof Tanks: Delivers rim-space overpressure protection on external and internal floating-roof tanks where vapor pressure can develop between roof and shell during routine operation.
Crude Oil Storage: Protects floating roofs on crude storage from rim-space pressure buildup during rapid product movement, thermal expansion, or rim seal degradation events.
Refined Product Tanks: Suits gasoline, diesel, and distillate floating-roof tanks where vapor generation and thermal expansion require defined rim-space pressure relief to protect roof structure.
Tank Farm Installations: Standardized 6" NPT configuration streamlines specification and installation across multiple floating-roof vessels on petroleum and refined product tank farms.
Petrochemical Storage: Provides rim-space relief on petrochemical floating-roof tanks where vapor pressure development threatens pontoon integrity and rim seal performance during routine operation.
Auxiliary Pressure Relief: Serves as auxiliary low-pressure relief on small low-pressure vessels where defined setpoint and simple weight-loaded construction satisfy protective pressure relief requirements.

Specifications

Parameter

Specification

Device Type

Floating-roof pressure rim vent

Function

Floating-roof pressure relief

Standard Set Pressure

1/2 oz/in² (0.865 in. W.C.)

Maximum Available Setting

5.7 oz/in² (10 in. W.C.)

Sealing Method

Weight-loaded pallet

Loading Method

Gravity / weight loading

Connection

6″ NPT screwed

Nominal Size

6″

Body Material

Cast Aluminum

Cover Material

Cast Aluminum

Screen Options

Galvanized Steel or 316 Stainless Steel

Certifications

ATEX (optional); CE (optional)

Temperature Range

Suitable for ambient outdoor tank-roof service

Options

Non-standard set pressure; 316 SS screen; ATEX certified version; CE certified version; custom tagging; protective coating options

2026 COST ESTIMATE

Contact Support

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

When should the 94126 be specified?

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The 94126 is specifically designed for floating-roof tanks where vapor pressure can accumulate in the rim space between the floating roof and the tank shell. It is installed directly on the floating-roof rim and provides low-pressure overpressure protection during product movement, thermal expansion, or rim seal malfunction events.

What is the standard set pressure?

Standard set pressure is 1/2 oz/in², equivalent to 0.865 in. W.C. Higher setpoints are available up to 5.7 oz/in² (10 in. W.C.) depending on configuration. Non-standard set pressures are available as an ordering option for specialized rim or auxiliary applications.

Why weight-loaded rather than spring-loaded?

The weight-loaded design provides repeatable opening without reliance on springs that fatigue over time or require periodic recalibration. On floating-roof installations exposed to outdoor weather, this simplicity reduces inspection and service requirements and supports long-term mechanical stability.

Are ATEX and CE certified versions available?

Yes. ATEX certified and CE certified versions are available as ordering options for installations where hazardous-area compliance or CE-regulated market requirements apply. Specify certification needs at order entry.

What body material options are available?

Standard body and cover construction is cast aluminum, selected for corrosion resistance in exposed outdoor floating-roof environments. Protective coating options are available for installations in severe atmospheric conditions where additional surface protection is required.

What screen options are offered?

Standard galvanized steel screen is offered for general service. 316 stainless steel screen is available as an option for enhanced corrosion resistance in aggressive environments, including coastal installations and sites with elevated atmospheric corrosion exposure.

How does the 94126 connect to the floating roof?

The 94126 uses a 6″ NPT screwed connection that mounts directly to floating-roof rim assemblies. This standardized threaded interface simplifies installation across multiple tanks and removes the need for flange-matching on floating-roof nozzle layouts.

Summary

With over a century of tank-safety heritage inside Cognesense, the Shand & Jurs 94126 Pressure Rim Vent is chosen for floating-roof tanks requiring rim-space overpressure protection during product movement, thermal expansion, and rim seal events. A weight-loaded pallet, cast-aluminum construction, integrated weather hood, and 6″ NPT connection deliver predictable low-pressure relief and simplified installation across crude oil, refined product, and petrochemical floating-roof service. For floating-roof pressure protection, it is trusted wherever you need to measure, monitor, and protect what matters most.

94126 Pressure Rim Vent