BS 4504 was the British standard for circular flanges for pipes, valves and fittings designated by PN. Section 3.1 covered steel flanges. It has been superseded by BS EN 1092-1, but BS 4504 flanges remain in service in plants, water works and buildings built in the UK, the Middle East, Africa and Asia, and replacements are still specified by that name.
Raaj Fittings supplies flanges to BS 4504 dimensions, or to the equivalent BS EN 1092-1 type and PN, made at our two plants in India in carbon and stainless steel and other grades.
BS 4504 and the German DIN standards shared a common PN system, and their dimensions were largely carried into EN 1092-1. For most sizes, a BS 4504 PN 16 flange matches an EN 1092-1 PN 16 flange of the same type, but there are differences in some sizes, facings and flange thicknesses. When ordering replacements, quote the standard on the drawing, or send the measured outside diameter, bolt circle, number and size of bolt holes and thickness.
BS 4504 flanges do not bolt to ASME B16.5 flanges, nor to the older BS 10 "Table" flanges (Table D, E, F, H) still found in some older UK installations. Check the standard of every mating flange.
Every BS 4504 flange is made from PMI-verified material, dimensionally inspected against the ordered standard and marked with material, size, rating and heat number. Orders are supplied with EN 10204 3.1 certificates; EN 10204 3.2 certification and inspection by the buyer's nominated third-party agency are available on request.
No. BS 4504 has been superseded by BS EN 1092-1, but flanges to BS 4504 dimensions are still supplied for existing installations and for drawings that specify it.
In most sizes and PN ratings they match, because EN 1092-1 was based on the earlier national standards. Some details differ, so check dimensions for critical replacements.
No. BS 10 used "Table" designations (Table D, E, F and others) and has different dimensions. BS 4504 uses PN ratings.
Yes, BS 4504 / EN 1092-1 flanges are available in stainless steel, carbon steel and other grades.