How to determine the weight of one metre of pipe: tables, standards and formulas

However, it is important to take one nuance into account in order to purchase the required quantity of pipes during construction or repair. Pipelines are measured in metres, both in drawings and in real life, while such products are sold by the tonne from mills and steel and metal warehouses. Therefore, to ensure that the quantity of the purchased material is not significantly less or more than what is required, it is necessary to calculate as precisely as possible how many of and what kinds of pipe are to be purchased, which means converting from metres to tonnes or vice versa.

The theoretical weight of steel pipe

This task may seem to be too complex, but, in fact, that is not the case, as there are standards in Ukraine and other countries under which steel pipes are produced. They specify requirements for the products and materials tubular products are produced from: density, pipe/tube wall thickness and other essential parameters. Thus, it becomes easier to determine the pipe/tube weight, that is, to convert metres to kilogrammes.

The key Ukrainian standard for the production of electric welded pipes and construction sections is DSTU EN 10214. However, several other regulatory documents are also applied:

• GOST 10704. Straight seam saw pipes. Product mix
• GOST 10705. Electric welded steel pipes. Specifications
• GOST 10706. Straight seam saw pipes. Technical specifications
• GOST 13663. Shaped steel pipes
• GOST 8731. Seamless hot-deformed steel pipes
• GOST 8732. Seamless hot-deformed steel pipes
• GOST 8733. Seamless cold-deformed and warm-deformed steel pipes
• GOST 8734. Seamless cold-deformed steel pipes and others

All the above GOSTs will be annulled in Ukraine in mid-2022, while remaining in force in the CIS.

How to determine the weight of a round pipe/tube?

Theoretical weight calculation tables for steel pipes were developed in compliance with these EN 10219-2 standards and other documents.

The round pipe theoretical weight calculation formula:

In order not to spend too much time searching for the required parameters in the tables, there is one more method used to convert metres into kilogrammes. A special formula is used to calculate theoretical weight of a one-metre pipe.

In its simplified form, it looks as follows:

• m = ρ*X where:
• m – estimated weight of 1 m pipe
• ρ — material density (depending upon steel grade)
• X – pipe cross section

There are different formulas for popular types of steel pipe. For instance, when calculating the weight of a round steel pipe, such geometrical characteristics as the outer diameter and wall thickness are taken into account. The approximate weight of one metre of round pipe can be calculated using the following formula:

m = π * (D - Sw) * Sw * ρ, where:

• π – number equal to 3.14
• D – pipe outer diameter
• Sw. – wall thickness
• ρ - material density / specific weight

However, it should be kept in mind that these are only approximate estimates. In fact, certain standard stipulated dimensional tolerances are possible in real production, and the actual steel density may vary significantly from the theoretical one as a result of the alloying system selected by the manufacturer. If this error is practically unnoticeable in small volumes, it amounts to of dozens and hundreds of kilogrammes in large tonnage orders.

In addition, the weight of the pipes in which diameter and wall thickness coincide may vary depending upon production method. There are seamless and welded pipes, and welded pipes, in turn, vary in weld joint type: single-joint, double-joint, longitudinally welded and spirally welded pipes.

The production technology also affects the selection of steel grade (and welding materials in the case of a welded pipe) and, therefore, its density.

Moreover, the use of a protective coating may influence the resulting weight of the product. For instance, when calculating the weight of galvanised pipe, it is necessary to take the zinc layer thickness and the difference between the coating density and the steel base into account.

Knowing the formulas and the main parameters of the pipes, it is possible to calculate in reverse, that is, to calculate an approximate length of pipes based on the product weight.

The round pipe weight calculation example:

How to determine the weight of one metre of carbon steel pipe with the following parameters:

• outer diameter is 70 mm
• wall thickness is 3 mm
• density is 7,850 kg/m3

m = 3.14*(0.07 — 0.003)*0.003*7,850=4.956 kg

In compliance with reference tables, the weight of one linear metre of pipe should be 4.96 kg. Therefore, the formula provides for quite a precise result.

And it does not end here. Formulas, tables, GOSTs and other ways of determining the weight of a one-metre pipe serve as an auxiliary tool only and seem designed for those who like spending their time with a calculator, drawings and formulas.

Digitalisation has also reached the realm of converting pipe length into weight. There are scores of sites and mobile applications where, with just a few clicks, it is possible to discover the weight of pipes needed for the repair of several dozen metres of the municipal water supply system or the installation of a new and multi-kilometre long gas pipeline to a promising natural gas deposit. This means that a steelmaker’s sales team will be able to convert the volume needed by the customer from metres to kilogrammes in a quick and precise manner and set clear parameters for the production of a steel blank, a steel billet for a seamless pipe or a strip for a welded pipe.