Standard & Approvals

British Standard (BS 3505:1968)
Normal Size Outside Diameter Class B - 06 Bar Class C - 09 Bar Class D - 12 Bar Class E - 15 Bar
Wall Thickness Wall Thickness Wall Thickness Wall Thickness
Inch Min Max Min Max Min Max Min Max Min Max
0.50 21.20 21.50             1.70 2.10
0.75 26.60 26.90             1.90 2.50
1.00 33.70 33.70             2.20 2.70
1.25 42.10 42.40         2.20 2.70 2.70 3.20
1.50 48.10 48.40         2.50 3.00 3.10 4.50
2.00 60.20 60.50     2.50 3.00 3.10 3.70 3.90 4.50
3.00 88.70 89.10 2.90 3.40 3.50 4.10 4.60 5.30 5.70 6.60
4.00 114.10 114.50 3.40 4.00 4.50 5.20 6.00 6.90 7.30 8.40
5.00 140.00 140.40 3.80 4.40 5.50 6.40 7.30 8.40 9.00 10.40
6.00 168.00 168.50 4.50 5.20 6.60 7.60 8.80 10.20 10.80 12.50
8.00 218.80 219.40 5.30 6.10 7.80 9.00 10.20 11.90 12.60 14.50
9.00 244.10 244.80 5.90 6.80 8.70 11.00 11.50 13.30 14.10 15.80
10.00 272.60 273.40 6.60 7.60 9.70 11.20 12.80 14.80 15.70 18.10
12.00 323.40 324.40 7.80 9.00 11.50 13.30 15.20 17.50 18.70 21.60
14.00 355.00 356.00 8.50 9.80 12.60 14.50 16.70 19.20 20.50 23.60
16.00 405.00 406.90 9.70 11.20 14.50 16.70 19.00 21.90 23.40 27.00
18.00 456.70 457.70 11.00 12.70 16.30 18.80 21.40 24.60    
20.00 507.50 508.50 12.20 14.10 18.10 20.90        


BS 3506:1969
Normal Size Outside Diameter Class O (Non-Pre) Class 6 Class 7
Wall Thickness Wall Thickness Wall Thickness
Inch Min Max Min Max Min Max Min Max
0.50 21.20 21.50     2.80 3.10 3.70 4.30
0.75 26.60 26.90     2.90 3.20 3.90 4.50
1.00 33.40 33.70     3.40 3.80 4.50 5.20
1.25 42.10 42.40     3.60 4.00 4.80 5.50
1.50 48.10 48.40 1.80 2.10 3.70 4.10 5.10 5.90
2.00 60.20 60.50 1.80 2.10     5.50 6.30
3.00 88.70 89.10 1.80 2.10        
4.00 114.10 114.50 2.30 2.60        
5.00 140.00 140.40 2.60 2.90        
6.00 168.00 168.50 3.10 3.40        
8.00 218.80 219.40 3.10 3.40        
9.00 244.10 244.80 3.10 3.40        
10.00 272.60 273.40 3.10 3.40        
12.00 323.40 324.30 3.10 3.40        
14.00 355.00 356.00 3.60 3.90        
16.00 405.90 406.90 4.10 4.50        
18.00 456.70 457.70 4.60 5.10