RULES OF THE WELDING FOR CONSECUTIVE WELDING

In the previous article in the Basic Metallurgy of fusion welding ,we learnt that  when we  weld the metal , there metallurgical properties is drastically change , In the fraction of the second.

In the span of that material , the welded joint is the weakest part of the material.

Then next question came in the mind , welding is mandatory joining process , how to make the material strongest.

To check the welding joint ,we take the help of NDT techniques just like the RT , UT etc.

To check that there is any  flaws in it or not.

Material is joint by welding process , then there is distance between two consecutive welding ,to avoid the overlapping of the Heat Affected Zone.

As we go near to the fusion zone welding proceed to the weakest part of the material , then RT & UT is mandatory for the welding.

To make welding stable BS British has set some standard for the different material grade

This is as fallows:

BS standard	Circular/ rule by years	Material Type	Rule
BS 2633	1987	FERRITE STEEL PIPE WORK	4 x Nominal thickness of pipe
BS 4515	2009	C-Mn Pipe line	4 x Nominal thickness of pipe
BS 2971	1991	Carbon steel pipe work	Agrees by parties

Remember this distance is not the Centre to centre distance of the welding , but it is end to end TOE of the welding.

Same rule we has to consider for equipment manufacturing because no rule is further set by the ASME Section 8 Div. 1 etc.

For Carbon Steel pipe it is mention that “ Agrees by Parties”

While doing the Any turnkey project or companies which work  in this sector drawn out the rule in the Method Statement Document.

This came by continuous practices & experience in this sector.

Normally in the process Engineering sector  , 3T Rule is very effective i.e. End of Toe to Toe 3 times thickness of the parent of basic material .

This for the carbon steel material only.

In equipment manufacturing ,like in the process industries typical equipment like Food of Chemical rectors , the complicated part of limpet coil welding , this rule of 3 T ( i.e. three times thickness of rector wall thickness should be very effective.

By fallowing this rule we avoid the NDT techniques of RT & UT

In manufacturing small small point is very effective , because if the running plant is get fail then huge loss in the business is happened .

So engineer should aware of all rule of manufacturing

Thanks

Prakash Patil