What is a Dished End? Types, Standards & Industrial Applications

Introduction

In industrial process equipment, dished ends (also known as pressure vessel heads or ASME heads) are critical components used to close the ends of cylindrical vessels. These engineered shapes ensure safe pressure containment, structural integrity, and long service life.

From storage tanks to high-pressure reactors, selecting the right dished end design is essential for performance, safety, and cost optimization.

What is a Dished End?

A dished end is a formed metal component welded to the ends of a pressure vessel or tank. It is manufactured from flat plates using forming processes such as pressing, spinning, or segmental fabrication.

Key Advantages

• Uniform pressure distribution

• Reduced stress concentration

• Lower thickness requirement vs flat plates

• Improved fatigue life

Dished ends are therefore essential for safe operation under pressure and temperature conditions in process industries.

Types of Dished Ends

1. Ellipsoidal Dished Ends (2:1 Elliptical Heads)

• Ideal for high-pressure applications 

• Excellent stress distribution

• Optimized thickness vs strength

2. Torispherical Heads (Flanged & Dished Heads)

• Most economical

• Widely used in moderate pressure vessels 

• Defined crown & knuckle radii as per ASME

3. Hemispherical Heads

• Best for very high-pressure applications 

• Uniform stress distribution

• Higher fabrication cost

4. Flat Dished Ends

• Used in low-pressure systems 

• Cost-effective and simple

• Common in tanks and columns

5. Conical Dished Ends

• Used where flow or discharge is required 

• Common in hoppers, silos, reactors, and separators 

• Allows gravity-assisted material flow

Key Features

• Custom cone angle based on process requirement

• Can be eccentric or concentric

• Often combined with cylindrical shells

👉 Ideal for industries handling powders, chemicals, and bulk solids

6. Segmental Dished Ends

• Used for large diameter vessels beyond press capacity

• Fabricated by welding multiple petal segments 

• Enables manufacturing of heads up to very large sizes

Key Features

• Suitable for heavy thickness plates 

• Requires precise welding and NDT

• Cost-effective for large-scale fabrication

👉 Common in refineries, petrochemical plants, and large storage systems

Standards & Codes for Dished Ends

To ensure safety and compliance, dished ends are manufactured according to:

• ASME Section VIII Division 1 & 2 

• PED (European Pressure Equipment Directive) 

• DIN 28011 / DIN 28013 

• IS / IBR Codes (India) 

These standards define geometry, thickness, stress limits, and inspection requirements.

Materials Used in Dished Ends

• Carbon Steel (CS)

• Stainless Steel (SS 304 / 316 / 310)

• Duplex & Super Duplex

• Nickel Alloys (Hastelloy, Inconel, Monel)

Material selection depends on:

• Corrosion resistance

• Temperature limits

• Pressure conditions

Industrial Applications of Dished Ends

Industries Served

• Oil & Gas

• Petrochemical

• Power & Boilers

• Aerospace & Defense

• Water Treatment

• Food & Pharma

Equipment Applications

• Pressure vessels

• Reactors & autoclaves

• Storage tanks

• Heat exchangers

Dished ends are critical for safe containment and process efficiency across industries.

How to Choose the Right Dished End

Key selection factors:

• Design pressure & temperature

• Diameter and thickness

• Process requirement (flow, storage, reaction)

• Applicable codes (ASME/PED)

• Manufacturing capability

Why Choose a Trusted Dished End Manufacturer

A reliable dished end manufacturer ensures:

• ASME-compliant fabrication

• Precision forming & welding

• Advanced manufacturing capability (press + segmental)

• Strict QA/QC and NDT

• Global project execution

KRR Engineering delivers custom-engineered dished ends with high precision, large capacity forming, and global standards compliance.

Conclusion

From ellipsoidal and torispherical heads to conical and segmental designs, dished ends are vital components in pressure vessel engineering. Each type serves a specific purpose based on pressure, application, and fabrication feasibility.

Choosing the right design and manufacturer ensures long-term reliability, safety, and performance in demanding industrial environments.

🚀 Request Custom Dished End Fabrication

Looking for a reliable dished end manufacturer in India for your next project?

📩 Email: bd@krr.co.in📞 Call / WhatsApp: +91 99400 98749

👉 Request custom dished end fabrication today and get precision-engineered solutions tailored to your exact requirements.