{"id":1001339,"date":"2025-09-08T12:18:11","date_gmt":"2025-09-08T10:18:11","guid":{"rendered":"https:\/\/www.protubsa.com\/faqs\/"},"modified":"2025-09-08T17:12:21","modified_gmt":"2025-09-08T15:12:21","slug":"faqs","status":"publish","type":"page","link":"https:\/\/www.protubsa.com\/en\/faqs\/","title":{"rendered":"Faqs"},"content":{"rendered":"\t\t
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\u00bf? Faqs <\/h2>\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t
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Frequently Asked Questions<\/h2>\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t\t<\/div>\n\t\t<\/div>\n\t\t\t\t
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\n\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\"Preguntas\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t\t<\/div>\n\t\t<\/div>\n\t\t\t\t\t<\/div>\n\t\t<\/section>\n\t\t\t\t\t<\/div>\n\t\t<\/div>\n\t\t\t\t\t<\/div>\n\t\t<\/section>\n\t\t\t\t
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<\/div>\n\t\t<\/div>\n\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t\t<\/div>\n\t\t<\/div>\n\t\t\t\t\t<\/div>\n\t\t<\/section>\n\t\t\t\t
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TUBES AND BARS<\/h5>\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t\t<\/div>\n\t\t<\/div>\n\t\t\t\t
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SERVICES<\/h5>\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t\t<\/div>\n\t\t<\/div>\n\t\t\t\t\t<\/div>\n\t\t<\/section>\n\t\t\t\t
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\n\t\t\t\t\t\t\t\t\t\t\t\t\t\n\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t<\/i><\/span>\n\t\t\t\t\t\t\t\t<\/i><\/span>\n\t\t\t\t\t\t\t\t\t\t\t\t\t\t<\/span>\n\t\t\t\t\t\t\t\t\t\t\t\tWhat is the meaning of S355J2H \/ NH, or S275J0H or S235JR ?<\/a>\n\t\t\t\t\t<\/div>\n\t\t\t\t\t

“S” : structural steel.
“355”: Minimum value of the apparent yield strength (N\/mm\u00b2)
“J2”: Breaking energy characteristics 27 Joules min. at -20\u00ba C.
“H”: Hollow section.<\/p>\n

Table of possible breaking energy conditions:
“J0” Breaking energy: 27 Joules at 0\u00ba C.
“JR” Breakdown energy: 27 Joules at room temperature.
“N” Breaking energy: 40 Joules at -20\u00baC. <\/p>\n

“NL”: Breaking energy: 27 Joules at -50\u00ba C.<\/p>\n<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t\t\t\t

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\n\t\t\t\t\t\t\t\t\t\t\t\t\t\n\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t<\/i><\/span>\n\t\t\t\t\t\t\t\t<\/i><\/span>\n\t\t\t\t\t\t\t\t\t\t\t\t\t\t<\/span>\n\t\t\t\t\t\t\t\t\t\t\t\tWhat types of certificates are there ?<\/a>\n\t\t\t\t\t<\/div>\n\t\t\t\t\t

EN10204.3.1.: Factory original.
EN10204.3.2.: Supported by independent certification company. (LRQA-UKAS, Lloyd’ s, DNV etc…)
EN10204.2.2. <\/p>\n

Protubsa supplies standard EN10204.3.1 certificates.
EN10204.3.2 certificates can be supplied upon request at the time of order.<\/p>\n<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t\t\t\t

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\n\t\t\t\t\t\t\t\t\t\t\t\t\t\n\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t<\/i><\/span>\n\t\t\t\t\t\t\t\t<\/i><\/span>\n\t\t\t\t\t\t\t\t\t\t\t\t\t\t<\/span>\n\t\t\t\t\t\t\t\t\t\t\t\tWhat are the main standards for building pipes ?<\/a>\n\t\t\t\t\t<\/div>\n\t\t\t\t\t

EN10219 (EN10219-1:2006) Cold-formed welded hollow structural sections of non-alloy and fine grain steel (also welded and seamless)
EN10210 (EN10210-1:2006) Hot finished hollow structural sections of non-alloy and fine grain steel. (welded, seamless and also seamless welded)
EN10025 (EN10025-3:2004) Hot rolled structural steel products.
EN10225 (EN10225:2009) Weldable structural steels for fixed marine structures.
EN10113 (EN10113-2:1993) Hot rolled products for metallic constructions. Welded fine grain steels. <\/p>\n<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t\t\t\t

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\n\t\t\t\t\t\t\t\t\t\t\t\t\t\n\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t<\/i><\/span>\n\t\t\t\t\t\t\t\t<\/i><\/span>\n\t\t\t\t\t\t\t\t\t\t\t\t\t\t<\/span>\n\t\t\t\t\t\t\t\t\t\t\t\tWhat is Eurocode 3 and how does it affect the welding of pipes according to manufacturing standards?<\/a>\n\t\t\t\t\t<\/div>\n\t\t\t\t\t

Eurocode 3 (Eurocode 3 or EN 1993) is the European standard for the design of steel structures. It includes criteria for design, safety and verification of joints, including welds, for both open section elements (I, H, U sections, etc.) and tubular elements (circular, square, rectangular).
For tubular elements (circular, square and rectangular sections), it is partly based on the recommendations of CIDECT (international association for steel construction with hollow tubes).
For pipes manufactured according to EN10210: No additional reductions apply.
For pipes manufactured according to EN10219: In some cases, the calculation must consider different properties between corners and walls \u2192 more conservative if no advanced rules are used (contact Protubsa staff for further restrictions). <\/p>\n<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t\t\t\t

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\n\t\t\t\t\t\t\t\t\t\t\t\t\t\n\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t<\/i><\/span>\n\t\t\t\t\t\t\t\t<\/i><\/span>\n\t\t\t\t\t\t\t\t\t\t\t\t\t\t<\/span>\n\t\t\t\t\t\t\t\t\t\t\t\tCan steel pipes be hot-dip galvanized and what are the options ?<\/a>\n\t\t\t\t\t<\/div>\n\t\t\t\t\t

Yes, of course, but the results obtained will depend in part on the quality of the steel and its chemical composition. Indeed, when steel is immersed in liquid zinc, a diffusion reaction takes place between the zinc and the steel. It is necessary to impose specifications for the respect of these two elements. The standard NF A35-003 “Steels for hot dip galvanizing” defines three classes of steel according to the guaranteed silicon and phosphorus content in the product.
Class 1: Si% < 0.030 Si% + 2.5P% <0.090
Class 2: Si% < 0.040 Si% + 2.5P% < 0.110
Class 3: 0.15 \u2264 Si% \u2264 0.030 Si% + 2.5P% < 0.325 P \u2264 0.040
For class 1 and to a lesser extent class 2 steels, they guarantee a coating with a uniform appearance and a thickness corresponding to the minimum values guaranteed in the NF ISO 1461 standard. For class 3 steels, the coating thickness is, under identical galvanizing conditions, in the order of 120 \u00b5m to 200 \u00b5m, although in some cases these limits can be exceeded. The appearance is generally duller than in the other classes 1 and 2. Gray or rough areas may appear, but this has no effect on the anti-corrosion properties. Their effective life is therefore longer.
For further information, please contact our sales staff.<\/p>\n<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t\t\t\t

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\n\t\t\t\t\t\t\t\t\t\t\t\t\t\n\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t<\/i><\/span>\n\t\t\t\t\t\t\t\t<\/i><\/span>\n\t\t\t\t\t\t\t\t\t\t\t\t\t\t<\/span>\n\t\t\t\t\t\t\t\t\t\t\t\tWhat is carbon equivalent - CE or Ceq ?<\/a>\n\t\t\t\t\t<\/div>\n\t\t\t\t\t

Carbon equivalent (CE or CEV) is a metallurgical parameter used to estimate how the chemical composition of a steel influences its weldability.
Formulas used:
Ceq -AWS: = C + [(Mn+Si)\/6 + (Cr+Mo+V)\/5 + (Ni+CU)\/15] long formula includes Si.
Ceq -O ‘ Neill: = C + [(Mn)\/6 + (Cr+Mo+V)\/5 + (Ni+CU)\/15] long formula
Ceq -short f.: = C + [(Mn)\/4] long formula includes Si. <\/p>\n<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t\t\t\t

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\n\t\t\t\t\t\t\t\t\t\t\t\t\t\n\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t<\/i><\/span>\n\t\t\t\t\t\t\t\t<\/i><\/span>\n\t\t\t\t\t\t\t\t\t\t\t\t\t\t<\/span>\n\t\t\t\t\t\t\t\t\t\t\t\tWhat is the difference between EN10297 and EN10294 for seamless pipes ?<\/a>\n\t\t\t\t\t<\/div>\n\t\t\t\t\t

One of the differences is that in EN10297 the dimensional range of external diameters is in inches (e.g. \u00d8 219.1) and in EN10294 it is defined in metric (e.g. \u00d8 200).
Another important issue is that in EN10297 the dimension is defined by \u00d8 Ext. x thickness and in EN10294 it is defined by \u00d8 Ext. x \u00d8 Int.
Last but not least, under EN10297 all manufacturers are governed by the same dimensional range of external diameters and thicknesses and under EN10294 there is a difference between the two standards, i.e. each manufacturer has different thicknesses and diameters. <\/p>\n<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t\t\t\t

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\n\t\t\t\t\t\t\t\t\t\t\t\t\t\n\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t<\/i><\/span>\n\t\t\t\t\t\t\t\t<\/i><\/span>\n\t\t\t\t\t\t\t\t\t\t\t\t\t\t<\/span>\n\t\t\t\t\t\t\t\t\t\t\t\tWhat is the calculation for the theoretical weight of a carbon steel round tube ?<\/a>\n\t\t\t\t\t<\/div>\n\t\t\t\t\t

The formula for the approximate calculation of the weight of one meter of carbon steel pipe is as follows:
Weight Kg\/Meter = [(\u00d8 Ext. – Thickness)* Thickness) * 0.0246615], where 0.0246615 is a constant.<\/p>\n<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t\t\t\t

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\n\t\t\t\t\t\t\t\t\t\t\t\t\t\n\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t<\/i><\/span>\n\t\t\t\t\t\t\t\t<\/i><\/span>\n\t\t\t\t\t\t\t\t\t\t\t\t\t\t<\/span>\n\t\t\t\t\t\t\t\t\t\t\t\tWhat are the main corrosion resistance tests for chrome-plated bars ?<\/a>\n\t\t\t\t\t<\/div>\n\t\t\t\t\t
1. Neutral Salt Spray Test (NSS or Neutral Salt Spray Test)<\/strong><\/span><\/h6>\n