9406X
↵
94080
↵
94069
↵
01

FRP Vents & Hatches

Corrosion-proof breathing and access for chemical storage.

What It Is & How It Works

FRP vents and hatches are fiberglass-reinforced polymer (FRP) tank fittings that provide pressure and vacuum breathing and personnel access on tanks storing highly corrosive liquids. They address the problem that metallic vents and hatches corrode and fail in concentrated acid, caustic, bleach, and brine service, creating safety and emissions risks as sealing surfaces degrade.

FRP pressure and vacuum vents operate on the same pallet-and-seat principle as metallic conservation vents, opening at defined pressure and vacuum set points to relieve breathing while controlling emissions. The difference is material: FRP resists the chemical attack that destroys carbon and stainless steel in aggressive vapor. FRP gauge hatches and manway covers provide gas-tight inspection and personnel access with corrosion-resistant sealing surfaces that hold integrity over years of exposure.

FRP vents and hatches mount to standard FRP or lined-steel tank nozzles. Selection depends on the stored chemical, its vapor composition, the required breathing rate, and the tank design pressure. Where the product would corrode metallic alternatives within months, FRP devices provide service lives measured in years without seal degradation or set-point drift.

FRP Vents vs. Metallic Vents

Metallic conservation vents serve most petroleum and chemical storage where vapor corrosivity is manageable. FRP vents are specified when the vapor would corrode metallic alternatives, typically concentrated acids, caustics, bleach, and aggressive brines. The choice is driven by chemical compatibility, not pressure or breathing performance.

When to Specify FRP Vents & Hatches

FRP vents and hatches are specified when the stored product’s vapor environment would corrode metallic tank fittings:

  • Concentrated Acid Storage: Tanks storing sulfuric, hydrochloric, phosphoric, or nitric acid where acid vapor destroys metallic vent pallets and sealing surfaces within weeks or months.
  • Caustic and Bleach Storage: Sodium hydroxide and sodium hypochlorite tanks where alkaline or oxidizing vapors attack metallic components, causing seal failure and uncontrolled emissions.
  • Chemical Manufacturing and Processing: Process tanks, day tanks, and intermediate storage handling multiple corrosive products where metallic vent replacement frequency is operationally unacceptable.
  • Water and Wastewater Chemical Feed: Chemical feed tanks at water treatment plants storing ferric chloride, alum, polymer, or hypochlorite that corrode standard fittings.
  • FRP and Lined Tank Installations: Fiberglass or rubber-lined steel tanks where the vessel is corrosion-resistant and the vent or hatch must match it to avoid being the weakest point.
Shand & Jurs 94060
02

Why It Excels

01

Tanks Where Metallic Vents Fail Within Months

FRP resists the chemical attack that destroys carbon steel, aluminum, and stainless steel vent components in aggressive vapor, giving service lives measured in years rather than months.

02

Facilities Where Frequent Vent Replacement Disrupts Operations

Replacing a corroded metallic vent means taking the tank out of service, draining or purging, and installing a new device; FRP vents match their life to the tank and break that cycle.

03

Applications Requiring Consistent Set-Point Performance

Corroded metallic pallet and seat surfaces drift, opening early or leaking; FRP sealing surfaces hold their dimensional accuracy and finish throughout the device's service life.

04

FRP and Lined Tanks Requiring Material Consistency

A metallic vent on an FRP tank creates a corrosion-vulnerable point atop an otherwise corrosion-proof vessel; FRP vents and hatches match the tank's material from nozzle to pallet.

05

FRP and Lined Tanks Requiring Material Consistency

Installing a metallic vent on an FRP tank creates a corrosion-vulnerable point at the top of an otherwise corrosion-proof vessel. FRP vents and hatches match the tank’s material capability from nozzle to pallet.

03

FRP Vents vs. FRP Hatches — Selection Guide

Attribute FRP Pressure & Vacuum Vents FRP Gauge Hatches & Manway Covers  
Primary Function
Pressure and vacuum breathing control with emissions containment Gas-tight inspection and personnel access to the tank interior  
Operating Mode
Opens automatically at defined pressure and vacuum set points Opened manually for gauging, sampling, or entry  
Normal-condition State
Sealed; opens only when a set point is reached Sealed; closed until operator access is required  
Sizing Basis
Breathing rate per API 2000 and tank filling/emptying Standard gauging or personnel access dimensions  
Regulatory Driver
EPA 40 CFR 60/63 emissions control, API 2000 API 653 inspection access, OSHA confined-space entry  
Sealing Technology
FRP pallet and seat with corrosion-resistant sealing surface FRP cover with corrosion-resistant gasket or bolted closure  
Recommendation
  • Specify for every corrosive-service tank needing controlled breathing and emissions compliance
  • Specify when the tank needs routine interior access and the vapor would corrode metallic hatch components
 

What to Consider Alongside FRP Vents & Hatches

Consider an alternative when:

  • The vapor environment does not attack metallic components. Standard conservation vents in carbon steel, aluminum, or stainless steel give equivalent breathing at lower cost. See Pressure & Vacuum Conservation Vents.
  • The tank requires fire-case relief in addition to normal breathing. FRP emergency vents are not standard; metallic emergency vents sized per API 2000 are required.
  • The vapor space contains flammable vapors needing certified flame interruption at the outlet. See Flame, Deflagration & Detonation Arresters.

How Frp Vents and Hatches Fit Into a Larger System

Pair FRP pressure and vacuum vents with FRP gauge hatches and manway covers so every opening in the roof matches the corrosion resistance of the FRP or lined vessel below. See Gauge Hatches & Manway Covers.

Combine with L&J Technologies radar or capacitance level gauges rated for corrosive service feeding Clairvoyance, so both the vent and the gauge resist chemical attack while inventory stays visible. See Radar Level Gauges and FuelsManager®.

04

Featured Products

01

Shand & Jurs 94060 FRP Pressure & Vacuum Conservation Vent

Fiberglass-reinforced conservation vent for corrosive service, providing controlled breathing at defined set points on acid, caustic, and bleach storage tanks.

02

Shand & Jurs 94069 FRP Gauge Hatch

Corrosion-resistant gauging and inspection access for tanks where metallic hatches fail in aggressive chemical vapor.

03

Shand & Jurs 94063 FRP Manway Cover

Corrosion-resistant personnel access for corrosive-service tank interiors, holding a gas-tight seal across years of chemical exposure.

05

Storing an aggressive chemical and worried about vent corrosion?

Talk to an engineer
↵
Shand & Jurs
Measure.
Monitor.
Protect.