Difference between two types of connections: butt weld (BW) and between BW and socket weld?
1. What is BW (butt weld, butt-welded joint)
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Connection of two pipe ends positioned face to face (end to end)
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Advantages: greater strength and tightness with a properly made weld, better resistance to high pressures and temperatures.
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Disadvantages: requires precise preparation and alignment, longer labour time, inspection is often necessary
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Applications: pressure installations, large diameters, steam pipelines, petrochemical industry.
Advantages:
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BW: full penetration provides greater strength and tightness; better stress distribution.
Disadvantages:
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BW: requires edge bevelling, precise alignment and space for weld penetration.

You can buy pipe nipples and nipples in our shop SHOP>>
2. What is Socket weld (socket weld)
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The pipe enters a socket of the corresponding shape of the component, the gap is welded around the face (a fillet weld is made).
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Advantages: easier alignment and installation, lower edge preparation requirements, good for small diameters (usually from 1/4"–4").
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Applications: small diameters, i.e. max. up to 4''. For installations where quick assembly is important.
Advantages:
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Socket weld: lower preparation requirements; tolerates larger gaps and less precise alignment.


If you are not sure which loose steel flange to choose, how to select the material, pressure class or method of corrosion protection – contact us.
We will help you select:
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Socket Weld coupling, union, cap.
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material (carbon steel, stainless steel),
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appropriate mating component
You can buy socket weld SW fittings here SHOP>>
We invite you to shop at PolBeris and contact us at tel. 63 2614 202 email: biuro@polberis.pl – we will prepare an offer tailored to your installation and help minimise costs while maintaining high technical parameters.