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Shand & Jurs 94069 FRP Gauge Hatch

FRP Corrosion-Resistant Gauge Hatch

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Shand & Jurs 94069 FRP Gauge Hatch

For terminal operators, chemical storage engineers, and wastewater specialists, the Shand & Jurs 94069 FRP Gauge Hatch provides controlled sampling and manual gauging access on atmospheric tanks handling corrosive vapors without degrading the sealing geometry that conservation vent control depends on.

Unlike metallic hatches that corrode at the seating surface and begin leaking continuously after repeated exposure to acids, caustics, or aggressive solvents, the 94069 uses a fiberglass reinforced plastic body in Derakane 470 vinyl ester resin and a PTFE air-cushion seal so the tank reseals predictably after every access event.

A weighted self-closing cover returns the hatch to a closed condition without operator intervention, restoring normal tank breathing behavior and limiting fugitive vapor loss. The hatch also provides supplemental pressure relief during abnormal pressure rise while remaining closed during standard operation.

Available in 4″, 6″, and 8″ sizes with flat-face flange mounting, the 94069 suits acid and caustic storage, wastewater digesters, and chemical processing tanks where corrosive service and repeatable sealing must coexist.

Shand & Jurs 94069
Shand & Jurs 94069 FRP Gauge Hatch
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Features

FRP Body Construction

Derakane 470 vinyl ester resin maintains sealing surfaces in corrosive vapor environments where metallic hatches degrade and begin leaking over time.

PTFE Air-Cushion Seal

Returns the tank to a vapor-tight condition after each access event, preserving conservation vent control and limiting continuous emissions between openings.

Weighted Self-Closing Cover

Automatically reseats after gauging without operator intervention, reducing operator-dependent vapor release events during routine sampling and manual gauging.

Supplemental Pressure Relief

Provides additional venting capacity during abnormal pressure rise while remaining closed during standard operation, reducing overpressure exposure on corrosive tanks.

Corrosion-Resistant Hardware

Stainless steel hinge hardware (Hastelloy optional) preserves consistent cover movement in aggressive atmospheres where standard fasteners would seize or fail.

Flat-Face Flange Mounting

Stable installation on non-metallic or lined tank nozzles, matching the corrosion-resistant construction of the tank rather than a metallic transition.

Applications

  • Acid Storage: Maintains vapor-tight resealing on sulfuric, hydrochloric, and similar acid tanks where metallic hatch components corrode rapidly and disrupt conservation vent control.
  • Caustic Tanks: Handles sodium and potassium hydroxide service where aggressive alkaline vapors attack standard hatch hinges, covers, and seating surfaces over time.
  • Wastewater Digesters: Provides sampling and gauging access on anaerobic and chemical-treatment tanks where hydrogen sulfide and organic acids degrade conventional hatch materials.
  • Chemical Processing: Supports solvent, specialty chemical, and process intermediate storage where metallic hatches lose sealing reliability within a few seasons of service.
  • Corrosive Vapor Service: Installs on tanks handling aggressive vapor spaces where conservation vent performance depends on a hatch that stays sealed between manual access events.
  • Sampling Access: Allows repeatable thief sampling on corrosive stocks while limiting the operator-dependent leakage path that drives chronic emissions at standard hatches.
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Specifications

Parameter

Specification

Device Type

Gauge/thief hatch

Nominal Sizes

4 in., 6 in., 8 in.

Mounting

Flat-face flange

Opening Method

Manual lift, self-closing

Sealing Method

PTFE air-cushion seal

Relief Function

Supplemental pressure relief

Standard Set Pressure

0.5 oz/in²

Maximum Pressure

8 oz/in² (4″, 6″); 4 oz/in² (8″)

Lock-Down Design Pressure

1 psig

Body

Derakane 470 Vinyl Ester (Standard); Derakane 411 or Furan available

Cover

FRP weighted lid

Hardware

Stainless steel (Standard); Hastelloy available

Options

Corrosion barrier construction; encapsulated weight assembly; alternative resin (Derakane 411 or Furan); lockdown cover (no supplemental relief); manual closing configuration; metric flange drilling (EN PN10/16); Hastelloy hardware

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Why use an FRP gauge hatch instead of an aluminum or stainless steel hatch?

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On tanks handling acids, caustics, or aggressive solvents, metallic hatches corrode at the seating surface and begin leaking continuously after repeated vapor exposure. The 94069’s Derakane 470 vinyl ester body and PTFE air-cushion seal maintain sealing geometry in environments where conventional materials degrade, preserving conservation vent control across the service life of the tank.

How does the 94069 reseal after a gauging or sampling event?

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A weighted self-closing cover returns the hatch to a closed condition automatically, without operator intervention. The PTFE air-cushion seal reseats against the FRP seat to restore vapor containment and normal conservation vent behavior between access events.

Does the 94069 provide any pressure relief function?

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Yes. The hatch provides supplemental pressure relief during abnormal pressure rise while remaining normally closed during standard operation. It is not a substitute for a primary relief device, but adds a secondary venting path on corrosive tanks where a metallic P/V valve might itself be compromised.

Can the 94069 be used on tanks with custom resin compatibility requirements?

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Yes. Derakane 470 is standard; Derakane 411 and Furan are available for specific chemical compatibility. Encapsulated weight assemblies and corrosion barrier construction can be specified for extended protection in aggressive vapor service.

What sizes and mounting options are available?

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The 94069 is offered in 4-inch, 6-inch, and 8-inch nominal sizes with flat-face flange mounting. ANSI flange drilling is standard; metric EN PN10/16 drilling is available for non-ANSI tank nozzle patterns.

How is the 94069 configured when supplemental relief is not desired?

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A lockdown cover option disables the supplemental pressure relief function, providing controlled access without a secondary vent path. This configuration suits tanks where the primary conservation vent architecture already provides required overpressure protection.

Summary

With over a century of tank-safety heritage inside Cognesense, the Shand & Jurs 94069 FRP Gauge Hatch is chosen when corrosive service would quickly degrade a metallic hatch and compromise conservation vent control. Its Derakane 470 vinyl ester body, PTFE air-cushion seal, and weighted self-closing cover return the tank to a predictable sealed condition after every access event. Across acid storage, wastewater digesters, and aggressive chemical tanks, the 94069 is trusted wherever you need to measure, monitor, and protect what matters most.

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