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Shand & Jurs 94225 P&V Emergency Vent and Manhole Cover

Hinged P&V Emergency Vent Manhole

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Shand & Jurs 94225 P&V Emergency Vent and Manhole Cover

For tank-farm specifiers, refinery engineers, and digester-cover designers, the Shand & Jurs 94225 integrates pressure relief, vacuum relief, emergency venting, and tank access within a single hinged manhole assembly, reducing nozzle count and tank-top hardware complexity.

Unlike split designs that use separate P/V vents, emergency vents, and manway covers — multiplying leak paths and roof reinforcement — the 94225 handles all four functions at one penetration, with a hinged full-lift emergency cover that opens wide for fire-case discharge.

Weight-loaded pressure and independently adjustable spring vacuum pallets control routine breathing. Setpoints span 2.5 to 16 oz/in² pressure and 0.57 to 2.9 oz/in² vacuum. Optional Expanda-Seal reduces vapor emissions and fugitive leakage to under 0.5 SCFH at 95 percent.

Sized per API 2000 with WinSize support. Available 16, 18, 20, 24, 30, 36, and 42 inches with ANSI Class 150 mounting; 20-inch and 24-inch sizes are also available for API-650 manway installation.

Shand & Jurs 94225
Shand & Jurs 94225 P&V Emergency Vent and Manhole Cover
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Features

Integrated P/V and Emergency Assembly

Combines routine pressure and vacuum breathing with hinged emergency relief and manway access inside a single tank-roof opening for simplified layout.

Hinged Full-Lift Emergency Cover

Opens wide during abnormal overpressure events for high-capacity discharge, reaching roughly 60 percent of perfect-orifice flow at 40 percent overpressure.

Independent Vacuum Adjustment

Spring-loaded vacuum assembly is adjustable without affecting the pressure setpoint, keeping operating-balance tuning decoupled during commissioning and service.

Serviceable Manway Design

Routine inspection and maintenance are performed through the hinged cover without unbolting the main flange or replacing the gasket seal.

Expanda-Seal Pressure Pallet Option

Self-energizing diaphragm holds leakage under 0.5 SCFH at 95 percent of setpoint, reducing fugitive emissions during normal tank operation near setpoint.

Wide Pressure Envelope

Pressure settings span 2.5 to 16 oz/in² with vacuum settings 0.57 to 2.9 oz/in², covering low-pressure through elevated tank operating programs on one platform.

Applications

  • Atmospheric Storage Tanks: Consolidates routine P/V breathing, emergency venting, and inspection access on a single penetration, reducing nozzle count and tank-top reinforcement requirements.
  • Fire Case Protection: Hinged full-lift cover delivers high-capacity emergency discharge sized per API 2000, limiting structural stress during external fire exposure or rapid vapor generation.
  • Petroleum Terminals: Protects product and intermediate tanks across a 2.5 to 16 oz/in² pressure envelope, matching the operating range common on terminal storage installations.
  • Chemical Storage: Aluminum, carbon steel, and 316 stainless steel bodies with alternate diaphragm elastomers extend service life in corrosive and aggressive vapor environments.
  • Tank Farms: Eliminates separate vent and manway installations, lowering total roof hardware count on large terminal and refinery storage fields.
  • Fixed Digester Covers: Protects covered wastewater and anaerobic digester vessels against biogenic and thermal pressure events while preserving inspection access through the same opening.
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Specifications

Parameter

Specification

Device Type

Combined P/V vent, hinged full-lift emergency vent, and manhole cover

Pressure Settings

2.5 oz/in² to 16 oz/in²

Vacuum Settings

0.57 to 2.9 oz/in² (adjustable)

Emergency Relief

Hinged full-lift cover

Flow Efficiency

~60% @ 40% overpressure; ~75% higher

Leakage (Expanda-Seal)

<0.5 SCFH at 95% of setpoint

Sealing Method

Diaphragm-sealed pressure pallet

Loading Method

Weight-loaded pressure; spring vacuum

Nominal Sizes

16″, 18″, 20″, 24″, 30″, 36″, 42″

Connections

ANSI Class 150; API-650 (20″ and 24″)

Sizing Basis

API 2000 (WinSize / EZ-Flow support)

Body and Seat

Aluminum, Carbon Steel, or 316 Stainless Steel

Pallets

Aluminum or 316 Stainless Steel

Diaphragm

FEP / FKM / PFA (Expanda-Seal optional)

Spring

Stainless Steel

Weights

Lead and Steel (standard); 316 Stainless Steel available

Hardware

316 Stainless Steel

Options

Expanda-Seal pallet, API-650 manway mounting, stainless steel construction, raised-face flange (CS/SS only), adjustable vacuum spring range, limit switches for remote indication

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

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How does the 94225 differ from the 94221?

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Both consolidate P/V venting, emergency relief, and manway access into one roof penetration. The 94221 uses a limited-lift emergency cover and is offered in 20″ and 24″ sizes with a lower pressure setpoint range. The 94225 uses a hinged full-lift emergency cover for higher-capacity emergency discharge, offers 16″ through 42″ sizes, and supports a wider pressure envelope (2.5 to 16 oz/in²) with independently adjustable vacuum.

Is the vacuum setpoint independent of the pressure setpoint?

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Yes. The 94225 uses a spring-loaded vacuum assembly that is adjustable without disturbing the pressure setpoint, so commissioning and field tuning of routine breathing balance remain decoupled from pressure relief tuning.

What emergency capacity does the hinged cover deliver?

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The hinged full-lift emergency cover reaches roughly 60% of perfect-orifice flow at 40% overpressure and approximately 75% at higher excursions, supporting API 2000 fire-case sizing. Capacity is confirmed per configuration through WinSize (EZ-Flow) software.

What sizes and mountings are available?

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The 94225 is offered in 16″, 18″, 20″, 24″, 30″, 36″, and 42″ sizes with ANSI Class 150 drilling. API-650 manway mounting is available in 20″ and 24″ for direct tank-roof installation. Larger or custom configurations can be confirmed with the factory.

When should Expanda-Seal be specified?

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Expanda-Seal is recommended where continuous vapor leakage near setpoint would carry an emissions, odor, or product-value penalty. It is an optional self-energizing pressure pallet that holds leakage under 0.5 SCFH at 95% of setpoint, compared with roughly 1.0 SCFH at 90% on a standard pallet.

Are limit switches available for remote indication?

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Yes. Limit switches can be specified to provide remote indication when the emergency cover is open, supporting DCS integration and alarm handling on monitored tank installations.

Summary

With over a century of tank-safety heritage inside Cognesense, the Shand & Jurs 94225 integrates pressure relief, vacuum relief, emergency venting, and manway access into a single hinged assembly, protecting atmospheric storage tanks and fixed digester covers during routine and fire-case events. Independently adjustable vacuum, a hinged full-lift emergency cover, and optional Expanda-Seal support stable operation and reduced fugitive emissions. Sized per API 2000 with WinSize support, the 94225 helps refineries, terminals, and chemical sites measure, monitor, and protect what matters most.

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Measure.
Monitor.
Protect.