Shand & Jurs 94103 Static Pressure Vacuum Vent

For petroleum terminal engineers, chemical storage specifiers, and tank designers, the Shand & Jurs 94103 provides vacuum relief for pressure-rated storage tanks that must withstand elevated internal static pressure when not relieving.

Unlike atmospheric vacuum vents that cannot tolerate significant between-event static pressure, the 94103 is designed for static pressures up to 150 PSIG, protecting against structural damage from rapid product withdrawal, cooling contraction, or vapor removal without compromising vessel pressure integrity.

A peripheral and stem-guided vacuum pallet ensures stable lift and controlled reseating during high-differential vacuum events. A cushion-seated Buna-N-coated nylon diaphragm enhances sealing integrity. Standard vacuum settings range from 1.0 to 16 oz/in², with extended settings up to 32 oz/in² available.

The self-draining body with drip ring reduces condensate at the seat. Supplied in 4″ nominal size with ANSI Class 150 raised-face flange, operating −50°F to +200°F, the 94103 is spec-ready for pressure-rated petroleum and chemical storage. CE is available to 0.5 barg service.

Features

Maintains structural integrity under elevated internal pressure, allowing vacuum protection on pressure-rated tanks without separate hardware on additional nozzles.

Controls lift alignment and reseating during repeated high-differential vacuum events, reducing chatter and uncontrolled airflow spikes across cyclic operation.

Buna-N-coated nylon diaphragm limits nuisance air infiltration while maintaining consistent seat contact through repeated thermal breathing and pump-out cycles.

Standard 1.0–16 oz/in² with extended capability up to 32 oz/in² supports low-to-elevated vacuum tolerance requirements across pressure-rated tank services.

Directs condensate away from seating surfaces, preserving sealing integrity on wet-vapor service and reducing maintenance exposure from corrosion and seat fouling.

4″ raised-face flange integrates directly into pressure-rated piping systems, removing the need for adapter spools or transition hardware on new installations.

Applications

Pressure-Rated Tanks: Delivers vacuum relief on storage tanks rated up to 150 PSIG static pressure where atmospheric vacuum vents would fail during between-event operation.
Petroleum Terminals: Protects against vacuum-induced roof and shell deformation on pressurized petroleum storage during rapid product withdrawal, cooling, or vapor removal events.
Chemical Storage: Buna-N-coated diaphragm and cast steel construction suit chemical tanks where vacuum protection must coexist with elevated static pressure and compatible vapor chemistry.
Static Pressure Service: Supports tanks intentionally held under static positive pressure between breathing events, where vacuum protection must tolerate continuous internal pressure up to 150 PSIG.
Rapid Product Withdrawal: Peripheral and stem-guided pallet geometry delivers stable vacuum admission during rapid pump-out, preventing structural damage from transient high-vacuum events.
Condensate-Prone Environments: Self-draining body and drip ring reduce condensate accumulation at seating surfaces, supporting reliable operation in wet-vapor and cold-weather service conditions.

Specifications

Parameter

Specification

Device Type

Static pressure vacuum vent

Standard Set Vacuum

Min 1.0 oz/in² (Al trim); 1.75 oz/in² (SS trim). Std max 16 oz/in² (lead); 12 oz/in² (SS). Extended max 32 oz/in² (lead); 20 oz/in² (SS)

Static Pressure Capability

Up to 150 PSIG (recommended service pressure 20 PSIG max). CE available for 0.5 barg max service pressure

Sealing Method

Cushion-seated diaphragm

Loading Method

Vacuum pallet

Nominal Size

4″

Flanged Connection

ANSI Class 150 Raised Face

Temperature Range

−50°F (−46°C) to +200°F (+93°C)

Body

Cast Steel or Cast Stainless Steel

Seat

Cast Aluminum (normal); Cast Stainless Steel (severe service)

Pallets

Aluminum; Stainless Steel available

Diaphragm

Buna-N-coated nylon

Screen

Galvanized Steel (normal); Stainless Steel (severe service); 30-mesh SS (Coast Guard option)

Weights

Lead (standard); Stainless Steel available

Hardware

Stainless Steel

Pallet Guide and Stem

Stainless Steel

Sizing Basis

Shand & Jurs WinSize

Approvals

CE available (0.5 barg max service pressure)

Options

Stainless steel 30-mesh screen (U.S. Coast Guard); cast stainless steel body; elevated vacuum settings; alternate diaphragm materials; custom flange drilling; special coatings

2026 COST ESTIMATE

Contact Support

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

How is the 94103 different from the 94100 high-pressure vacuum vent?

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Both provide vacuum protection on pressure-rated tanks. The 94103 is a 4″ unit rated up to 150 PSIG static pressure, with peripheral and stem-guided pallet geometry and Buna-N-coated nylon diaphragm sealing. The 94100 covers 6″ (125 PSIG) and 10″ (75 PSIG) sizes with balanced-pallet construction. Selection follows tank size and static pressure rating.

What vacuum settings are available?

Standard settings range from 1.0 oz/in² (with aluminum trim) up to 16 oz/in² (lead weights) or 12 oz/in² (stainless weights). Extended settings go up to 32 oz/in² (lead) or 20 oz/in² (SS). Minimum setting with stainless trim is 1.75 oz/in².

What is the maximum recommended service pressure?

The 94103 is rated for 150 PSIG static pressure capability, but recommended service pressure is 20 PSIG maximum. CE approval is available for service up to 0.5 barg. Specify actual service conditions at order entry so factory selection matches the application.

Is a U.S. Coast Guard option available?

Yes. A 30-mesh stainless steel screen option meets U.S. Coast Guard requirements when specified. This option is commonly selected on marine-adjacent terminals and petroleum storage sites falling under USCG jurisdiction.

What is the operating temperature range?

The 94103 operates from −50°F (−46°C) to +200°F (+93°C). The lower bound covers cold-climate and thermal contraction service, and the upper bound covers most petroleum and compatible chemical storage without requiring specialty-temperature construction.

How is relief capacity sized?

Capacity is sized using Shand & Jurs WinSize based on anticipated vacuum flow rates and allowable pressure drops. Sizing documentation supports defensible engineering selection and integrates with the applicable code-of-construction review at the site.

Can the body be supplied in stainless steel?

Yes. A cast stainless steel body option is available for aggressive vapor service where cast steel construction would corrode. Stainless screen and alternate diaphragm materials are also available for more severe service conditions.

Summary

With over a century of tank-safety heritage inside Cognesense, the Shand & Jurs 94103 Static Pressure Vacuum Vent is chosen when vacuum relief must coexist with static pressure up to 150 PSIG on pressure-rated storage tanks. A peripheral and stem-guided pallet, Buna-N-coated diaphragm, self-draining body with drip ring, and wide vacuum setting range deliver predictable vacuum admission and spec-ready integration into petroleum and chemical storage. For pressure-rated tank service, it is trusted wherever you need to measure, monitor, and protect what matters most.

94103 Static Pressure Vacuum Vent