Dished & Flanged Heads
“Dished head” is used broadly. A torispherical profile includes a crown and a knuckle transition; F&D, shallow-dished and dished-only descriptions should be checked against the actual drawing.
Technical specification information
Specifications to confirm
Crown radius, knuckle radius, depth and straight flange describe different parts of the head.
- Diameter and its ID or OD basis.
- Crown radius and knuckle radius.
- Depth, overall height and straight-flange dimension.
- Thickness basis, units and tolerances.
General Notes
- Provide a profile or section drawing.
- State the intended geometry standard and edition.
- Identify whether a straight flange is part of the requirement.
A geometry designation does not identify every requirement of a pressure-vessel component. Keep the design code, material specification and inspection requirements distinct.
- Material grade and product form.
- Applicable geometry and design requirements.
- Inspection scope and required records.
The project drawing and responsible engineer define the vessel or system design. Confirm the scope for the actual component before ordering.
Standards
Identify the applicable design, geometry, material and inspection standards and their editions. A similar head profile does not by itself establish compliance with a standard or certification requirement.
Application
Describe the intended vessel or tank service, medium and design conditions. Confirm the suitability of the head profile, material and supply requirements with the responsible project engineer.
Preparing your SIDA enquiry
Include the drawing revision and quantity. If a term in an existing specification is unclear, show the required profile and highlight the dimension that needs confirmation.
Request a quotation or review the quotation preparation guide.
Product views & technical information
Photographs from the SIDA catalogue. Use your drawing to establish the required dimensions, material and finish.
View the dimensions & drawing guideBefore you enquire.
Are all dished-head terms interchangeable?
No. Confirm the geometry and standard rather than assuming that torispherical, F&D, shallow-dished and dished-only mean the same profile.
Read the main guide →Which radii should I include?
Where the profile uses them, provide the crown and knuckle radii separately, together with the diameter, height and straight-flange dimensions.
Read the main guide →