Pressure Vessel Manway Assembly

Product Specifications

Technical details and manufacturing context for Pressure Vessel Manway Assembly

Definition

A standardized manway assembly providing safe, pressure-tight access to the interior of metal tanks, reservoirs, and pressure vessels. This critical component enables inspection, maintenance, and cleaning operations while maintaining structural integrity and containment. It serves as an essential interface point in industrial storage systems, manufactured by specialized metal fabricators for integration into larger containment structures. The assembly is supplied to tank manufacturers and industrial plant operators as a certified sub-assembly. The assembly typically consists of a flanged opening welded or bolted to the vessel shell, a removable cover plate, a gasket, and bolting. The cover plate is secured by multiple bolts that compress the gasket to create a leak-tight seal. The design allows for full access when opened, facilitating internal inspection, cleaning, and maintenance. The manway is engineered to withstand the design pressure and temperature of the vessel, with materials selected for compatibility with the contained media. Common materials include carbon steel and stainless steel 316L, with material grades such as Q245R, Q345R, 304, and 316L. The assembly is available in standard nominal diameters from 400 to 600 mm, with design pressures from 1.0 to 1.6 bar, and design temperatures from -20°C to 350°C. Flange thickness ranges from 30 to 50 mm, bolt circle diameter from 480 to 680 mm, and cover plate thickness from 20 to 40 mm. Sealing surface finish is typically Ra 3.2 to 6.3 μm, and leakage rate at design pressure is ≤0.1 mL/min. Weight varies from 50 to 150 kg depending on size and material. These parameters are reference ranges and must be verified for the specific model and application. The assembly is designed and tested according to material standards GB/T 713 and ASTM A240. Always confirm model-specific values and standards with the legal manufacturer or supplier.

Working Principle

The manway assembly operates as a flanged opening with a removable cover plate that seals against a gasket using multiple bolts. When closed, the bolts compress the gasket between the flange and cover, creating a pressure-tight barrier that prevents leakage. When opened, the cover is removed to provide full access to the vessel interior. The sealing effectiveness depends on proper bolt torque, gasket condition, and surface finish. The design ensures that the seal remains intact under design pressure and temperature conditions.

Common Materials

Carbon Steel, Stainless Steel 316L

Technical Parameters

Parameter	Typical range	Notes & selection driver
Nominal DiameterRequired	400–600 mm	Standard opening size (DN400, DN500, DN600)ISO 5208
Design PressureRequired	1.0–1.6 bar	Maximum allowable working pressureISO 5208
Design TemperatureRequired	-20–350 °C	Operating temperature rangeISO 5208
Flange ThicknessRequired	30–50 mm	Thickness of mounting flangeISO 5208
Bolt Circle DiameterRequired	480–680 mm	Diameter of bolt hole patternISO 5208
Cover Plate ThicknessRequired	20–40 mm	Thickness of removable coverISO 5208
Material Grade	Q245R, Q345R, 304, 316L	Carbon steel or stainless steelGB/T 713, ASTM A240
Sealing Surface Finish	Ra 3.2–6.3 μm	Smoother finish improves sealISO 5208
Leakage Rate	≤0.1 mL/min	At design pressureISO 5208
Weight	50–150 kg	Depends on size and material

Ranges are indicative industry figures for RFQ preparation, not a supplier commitment. Confirm every value and standard with the legal manufacturer before ordering.

Components / BOM

Flange Ring Part
Provides mounting surface and structural connection to vessel wall

Material: Carbon Steel or Stainless Steel
Cover Plate Part
Removable pressure barrier with lifting lugs

Material: Carbon Steel or Stainless Steel
Gasket Part
Creates pressure-tight seal between flange and cover

Material: Graphite or PTFE
Bolting Set Part
Secures cover plate to flange with specified torque

Material: Alloy Steel
Hinge Assembly Optional
Optional swinging mechanism for cover plate

Material: Carbon Steel

Industry Taxonomies & Aliases

Commonly used trade names and technical identifiers for Pressure Vessel Manway Assembly.

Manufacturers of Pressure Vessel Manway Assembly

Manufacturer profiles associated with Pressure Vessel Manway Assembly.

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Frequently Asked Questions

What is the purpose of a manway assembly?

It provides a pressure-tight access point for inspection, maintenance, and cleaning of metal tanks and pressure vessels.

What materials are commonly used?

Carbon steel and stainless steel 316L, with grades such as Q245R, Q345R, 304, and 316L.

What are typical design parameters?

Nominal diameter 400-600 mm, design pressure 1.0-1.6 bar, design temperature -20 to 350°C, and leakage rate ≤0.1 mL/min at design pressure.

How should I verify the assembly for my application?

Confirm all model-specific values, materials, and standards with the legal manufacturer or supplier before procurement.

Data Basis

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Preliminary Technical Classification

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pressure:	Up to 150 psi (standard), custom designs up to 300 psi
other spec:	Slurry concentration: Up to 60% solids by weight, Flow rate: Dependent on vessel size and application
temperature:	-40°C to 200°C

Product Specifications

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