Enter a flange or pick one from the list, or give the number of holes and their diameter. Below, an offered set such as 8 x M16 can be checked against the result.
On the count and size alone: the length, the material and the grade are checked separately.
Flanged joints on pipes, pumps, valves and tanks are held by a set of bolts or studs whose number and size the flange standard sets. Enter the flange (DN100 PN16, 4" 150#, NPS 4 Class 300, 10K 100A) or the holes you counted and measured, or pick a flange from the list: the finder gives the number and size of the studs and nuts, the stud length where the ASME B16.5 table gives one, draws the flange face, checks an offered set and writes an RFQ line.
It covers EN 1092-1 PN6 to PN40 (DN10 to DN300), ASME B16.5 Class 150 and 300 (NPS 1/2 to 12) and JIS B 2220 5K, 10K and 16K (10A to 300A). Bolt torques, bolt loads and gasket stresses are not given here: they depend on the gasket, the bolt grade and the service, and come from the gasket maker or the assembly procedure of the joint.
For each size and rating the standard sets the number of holes and their diameter, and with them the bolt: EN 1092-1 DN100 PN16 takes eight M16, ASME B16.5 NPS 4 Class 150 eight 5/8 in, JIS 10K 100A eight M16. The same size in another rating may take other bolts.
ASME B16.5 tables give a stud length for raised face flanges. EN 1092-1 and JIS B 2220 do not: the length follows from the two flanges, the gasket and the nuts, so it is measured or added up.
A stud takes two nuts, a bolt one. The grade (8.8, A4-70, B7 with 2H nuts) is chosen for the service and the flange material and goes in the request; the marking on the old bolt shows what was fitted.
| Size | PN6 | PN10 | PN16 | PN25 | PN40 | Class 150 | Class 300 | 5K | 10K | 16K |
|---|---|---|---|---|---|---|---|---|---|---|
| DN10, 10A | 4 holes of 11 mm | 4 x M12 | 4 x M12 | — | — | — | — | 4 holes of 12 mm | 4 x M12 | 4 holes of 15 mm |
| DN15, NPS 1/2, 15A | 4 x M10 | 4 x M12 | 4 x M12 | 4 x M12 | 4 x M12 | 4 x 1/2 in, L 2 1/4 in | 4 x 1/2 in, L 2 1/2 in | 4 x M10 | 4 x M12 | 4 x M12 |
| DN20, NPS 3/4, 20A | 4 x M10 | 4 x M12 | 4 x M12 | 4 x M12 | 4 x M12 | 4 x 1/2 in, L 2 1/2 in | 4 x 5/8 in, L 3 in | 4 x M10 | 4 x M12 | 4 x M12 |
| DN25, NPS 1, 25A | 4 x M10 | 4 x M12 | 4 x M12 | 4 x M12 | 4 x M12 | 4 x 1/2 in, L 2 1/2 in | 4 x 5/8 in, L 3 in | 4 x M10 | 4 x M16 | 4 x M16 |
| DN32, NPS 1 1/4, 32A | 4 x M12 | 4 x M16 | 4 x M16 | 4 x M16 | 4 x M16 | 4 x 1/2 in, L 2 3/4 in | 4 x 5/8 in, L 3 1/4 in | 4 x M12 | 4 x M16 | 4 x M16 |
| DN40, NPS 1 1/2, 40A | 4 x M12 | 4 x M16 | 4 x M16 | 4 x M16 | 4 x M16 | 4 x 1/2 in, L 2 3/4 in | 4 x 3/4 in, L 3 1/2 in | 4 x M12 | 4 x M16 | 4 x M16 |
| DN50, NPS 2, 50A | 4 x M12 | 4 x M16 | 4 x M16 | 4 x M16 | 4 x M16 | 4 x 5/8 in, L 3 1/4 in | 8 x 5/8 in, L 3 1/2 in | 4 x M12 | 4 x M16 | 8 x M16 |
| DN65, NPS 2 1/2, 65A | 4 x M12 | 8 x M16 | 8 x M16 | 8 x M16 | 8 x M16 | 4 x 5/8 in, L 3 1/2 in | 8 x 3/4 in, L 4 in | 4 x M12 | 4 x M16 | 8 x M16 |
| DN80, NPS 3, 80A | 4 x M16 | 8 x M16 | 8 x M16 | 8 x M16 | 8 x M16 | 4 x 5/8 in, L 3 1/2 in | 8 x 3/4 in, L 4 1/4 in | 4 x M16 | 8 x M16 | 8 x M20 |
| DN100, NPS 4, 100A | 4 x M16 | 8 x M16 | 8 x M16 | 8 x M20 | 8 x M20 | 8 x 5/8 in, L 3 1/2 in | 8 x 3/4 in, L 4 1/2 in | 8 x M16 | 8 x M16 | 8 x M20 |
| DN125, NPS 5, 125A | 8 x M16 | 8 x M16 | 8 x M16 | 8 x M24 | 8 x M24 | 8 x 3/4 in, L 3 3/4 in | 8 x 3/4 in, L 4 3/4 in | 8 x M16 | 8 x M20 | 8 x M22 |
| DN150, NPS 6, 150A | 8 x M16 | 8 x M20 | 8 x M20 | 8 x M24 | 8 x M24 | 8 x 3/4 in, L 4 in | 12 x 3/4 in, L 4 3/4 in | 8 x M16 | 8 x M20 | 12 x M22 |
| DN200, NPS 8, 200A | 8 x M16 | 8 x M20 | 12 x M20 | 12 x M24 | 12 x M27 | 8 x 3/4 in, L 4 1/4 in | 12 x 7/8 in, L 5 1/2 in | 8 x M20 | 12 x M20 | 12 x M22 |
| DN250, NPS 10, 250A | 12 x M16 | 12 x M20 | 12 x M24 | 12 x M27 | 12 x M30 | 12 x 7/8 in, L 4 1/2 in | 16 x 1 in, L 6 1/4 in | 12 x M20 | 12 x M22 | 12 x M24 |
| DN300, NPS 12, 300A | 12 x M20 | 12 x M20 | 12 x M24 | 16 x M27 | 16 x M30 | 12 x 7/8 in, L 4 3/4 in | 16 x 1 1/8 in, L 6 3/4 in | 12 x M20 | 16 x M22 | 16 x M24 |
A bolt size, count or stud length is given only where at least two independent tables give it; what they do not agree on is left out. Left out: the thread for DN10 PN6, 5K 10A and 16K 10A (one table each); the hole diameter of NPS 1/2 Class 300 (the tables differ); stud lengths for ring joint flanges. EN 1092-1 DN65 PN10 to PN40 has eight holes; cast iron flanges to EN 1092-2 may have four. A dash: the size is not in that rating here.
The flange drilling comes from the flange identifier on this site. The bolt sizes and counts were checked against five published EN 1092-1 tables, two JIS B 2220 tables and four ASME B16.5 bolting tables of flange, valve and bolt makers and engineering references; the ASME stud lengths against three bolting tables, two in inches and one in millimetres.
Eight M16 bolts or studs in 18 mm holes, by EN 1092-1. DN100 PN10 has the same drilling; PN25 and PN40 take eight M20 in 22 mm holes, and PN6 four M16. Two flanges bolted together share one set: eight studs and sixteen nuts.
The B16.5 table gives a stud length for each size and class of raised face flange: for NPS 4 Class 150 it is 3 1/2 in, for NPS 4 Class 300 4 1/2 in. It allows for two flanges, a gasket and two nuts. Ring joint flanges, spacers, wafer valves or a thick gasket need longer studs.
EN 1092-1 and JIS B 2220 set the flange and its holes, not the bolt length: that depends on the flange type, the gasket and what sits between the flanges. Measure the old stud, or add both flange thicknesses at the holes, the gasket, two nuts and some thread beyond each nut.
A 5/8 in bolt passes through an 18 mm hole, but its thread and nuts are inch: they do not match an M16 set, and a mixed set is hard to keep on board. Order the size the standard of the flange sets, and say so in the request if the flange was drilled to another standard.
The flange with its standard, the number and size of the studs, the nuts, the length, the material or grade and the number of sets: bolt set for flange DN100 PN16 (EN 1092-1), 8 x M16 stud bolts with 16 nuts, the length as measured on the old stud, grade 8.8, 4 sets. If the marking on the old bolts can be read, give it as well.
The table gives the bolting the standard sets, not the bolts fitted on board. Attach a photograph of the flange and an old stud, and Vessel Core checks them before an offer goes back.
