BSI Code

BRITISH STANDARD

The European Standard EN ISO 16812:2007 has the status of a
British Standard

ICS 75.180.20; 27.060.30

12 &23 375 to u 750 (15 to 30)

± 0,15 (0,006)

> 51 to u 1 125 (31 to 45)

± 0,20 (0,008)

> 1 125 (45)

18

Tolerance

± 0,20 (0,008)

LICENSED TO INDIAN INSTITUTE OF TECHNOLOGY - KHARAGPUR, FOR INTERNAL USE AT THIS LOCATION ONLY, SUPPLIED BY BOOK SUPPLY BUREAU.

9.7.1

EN ISO 16812:2007

9.8.4 The flatness tolerance on pass-partition grooves and mating pass partition plate edges shall be
0,8 mm (1/32 in).
9.8.5 The flatness of gasket contact surfaces shall be measured with a dial gauge. However, the flatness of the pass partition grooves and mating pass partition plate edges may be measured with a straight edge.
9.8.6 Flange flatness tolerance and surface finish shall be measured after the flange has been attached to the component cylinder or the cover, and after any post-weld heat treatment.

9.9

Tube holes

9.9.1

Tube-hole grooves shall be square-edged, concentric and free from burrs.

9.9.2 If austenitic stainless steel, duplex stainless steel, titanium, cupro-nickel or nickel-alloy tubes are specified, the tube holes shall be machined in accordance with TEMA (8th edition), Table RCB-7.41, column (b) (Special Close Fit).

9.10 Tube-to-tubesheet joints
9.10.1 If roller-expanded joints are utilized, the tube wall thickness reduction shall be in accordance with
Table 4.
Table 4 — Maximum allowable tube wall thickness reduction for roller-expanded tube-to-tubesheet joints
Material

Maximum tube wall thickness reduction
%

Carbon steel and low-alloy (max. 9 % chromium) steel

8a

Stainless and high-alloy steel

6a

Titanium and work-hardening non-ferrous

5a

Non-ferrous non-work-hardening (e.g. admiralty brass)

8a

a

These may be increased by a further 2 % if approved by the purchaser.

9.10.2 If welded-and-expanded joints are specified, tube-wall thickness