Düker Glass-Lined
Steel Pipe and Fittings Dimensions and Tolerances |
Lengths of welded pipe and fittings (before glass-lining) = Nominal Length of glass-lined
parts minus 2 mm ; applicable tolerance +1 mm / -2 mm
Tolerance and limit dimensions for glass-lined parts adhere to DIN 2873 resp. 28007.
Glass must be tested at 20,000 volts DC initially with
a follow-up test at 12,000 volts immediately before shipping. Visual inspection must
be made by refraction of the glass surface.
Glass thickness to be 1 to 2 mm (40 to 80 mils) in accordance with DIN standard 2873,.
X-rays to be carried out on 5 percent of all circumfernetial welds (non-lethal service). 100 percent on lethal service.
1) Pipes must be straight. Deviation in (mm) must not exceed 1.25 times the length in (m).
Ex. Pipe (L) = 1 meter, then deviation can not be greater than 1.25 mm
2) Angularity
| Diameter | Tolerance in mm Angularity Pipe Length 20 |
Tolerance in mm Angularity Pipe Length > 20 |
Tolerance in mm Angularity for a fitting |
| 1" to 10" | 0.5 mm | 0.8 mm | 0.8 mm |
* Drawing for DIN 2873 which goes with this chart will be sent on Monday.
3) Acceptable Lengths Difference For Pipes
| Pipe Length Under 1' | Pipe Length over 1' to 3' | Pipe Length over 3' to 10' |
| 0 to -3.0 mm | 0 to -4.0 mm | 0 to -5.0 mm |
4) Acceptable Length Differences For Fittings
| Dia. 1" to Dia 2" | Dia. 2-1/2" to Dia. 4" | Dia. 5" to Dia. 8" | Dia. 10" and larger |
| 0 to -3.0 mm | 0 to -3.5 mm | 0 to -4.0 mm | 0 to -4.5 mm |
5) Planarity
The evenness will be measured by feelers between the welding neck face and a level plate.
At no point may feeler be inserted >1 mm (up to 10"components), > 2 mm (up to
16"components) from inside or outside further than the center point of the face
6)Acceptable Variation in Diameter for the Stub Ends
| Diameter | Max. Variation |
| 1" to 8" | ± 2 mm |
| 10" to 12" | ± 4 mm |
| 12" to 24" | ± 6 mm |
The largest dimension for the outer diameter of the stub end must be within the minimal
centering diameter of the loose flanges.
Paint Spec : Paint Type GB-Zinc Ethylsilicate, suitable
temperature Range - 58oF to 752oF, 1 coat if sprayed or 2 coats if
painted by hand, thickness 80 µm to 120 µm (min. 60 µm)
INTERNAL WORK STANDARDS IN THE DUKER QUALITY CONTROL MANUALS:
| Description | DIN | ANSI |
| Pipe Spools | WN 108.014 | WN 108.015 |
| 45o Elbow | WN 108.031 | WN 108.032 |
| 90o Elbow | WN 108.034 | WN 108.036 |
| Standard Tee | WN 108.097 | WN 108.134 |
| Reducing Tee | WN 108.049 | WN 108.136 |
| Standard Cross | WN 108.037 | WN 108.135 |
| Reducing Cross | WN 108.052 | |
| Concentric Reducer | WN 108.123 | WN 108.138 |
| Reducing Flange | WN 108.017 | WN 108.019 WN 108.056 |
| Spacers | WN 108.016 | WN 108.033 |
| Blind Flange | WN 108.007 | WN 108.008 |
| Instrument Tee | WN 108.131 | |
| Angle Spacer | WN 108.050 |
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