Hello,Guys,

I&E range is a nonessential variable which need to addressed in WPS per ASME IX, Now I have a WPS with toughness requirement, but I am wondering if this variable is mandatory or recommended when I specify it in WPS. If it is mandatory,there will be a lot of NCR opened at site, Any tips?

I&E relate directly to heat input. Heat input is a supplementary essential variable in most (if not all) methods. Simply put, when notch toughness is required by other codes supplementary essential variables become ESSENTIAL VARIABLES.

Start writing....

thx,jon20013

I knew that HI will become essential variable when toughness is required. But what i want to know is the" I & E range".......You know,sometimes, the Heat input calculated by the I and E used in production welding is acceptable, however, that I or E value exceeds the range specified in WPS, do we need to open a NCR? or just update the WPS and ... the I & E range ?

I & E Range is nonessential so no need to worry as long as you remain within your heat input values. Suggest monitoring may be in order to ascertain.

Dephy,

AS Jon indicated, how are you monitoring the Heat input, if not by Electric Current (I) in Ampere and Potential (E) in Volt with the travelspeed?
Unit length can be used as well, but without I and E, it does not work.

If Impact testing of WPS is a Code requirement and your PQR qualifies a certain Heat Input, you are going to need the control.

When your WPS specifies 20-24 V and 100-120 A, the range shall be followed of course.
Any violation, e.g. 130 A requires an NCR and consecutively a revised WPS with the evaluation whether or not the actual welding was qualified. According to the definition of nonconformities, I think this is one, right?

DK

Dr K,
As both yourself and Jon have noted Amps / volts is a non essential variable and heat input is an essential variable for impact tested applications.
So if a WPS states maximum amps 120 for impact tested applications and someone welds at 130 it is my opinion that no non conformance has occurred - poor practice yes, a revised WPS yes, but the weld could well be in compliance with the code.
I will use your suggested WPS range of 20 - 24 volts, 100-120 amps and I will use hypothetical PQR recordings of 22 volts, 110 amps and 90 mm/min travel speed.
This gives me a maximum heat input of 1.61 kj/mm and we cannot exceed that in production.
If I stay at 22 volts, increase amps to 130 and keep the same travel speed of 90 mm/min I end up with a heat input of 1.90 kj/mm.
Definitely does not comply with the code and an NCR could be quite legitimately issued (and the weld cut out).
However, for a welder who prefers to weld hot and fast (as I always liked to)there could be a different scenario.
22 volts, 130 amps and 110 mm/min travel speed will give you a heat input of 1.56 kj/mm.
Complies with the code but as stated before is not good practice (exceeding the WPS) and a revision of the WPS is required.
That is why writing a good WPS in the first place is so important.
It is critical to provide as much "flexibility" as possible while also keeping a tight control on parameters that may be detrimental to the weld.
Regards,
BB

ASME IX is pretty specific under "Contents of the WPS," that is, the WPS SHOULD list ALL essential, supplementary essential AND NON-ESSENTIAL variables.

That said, I don't believe a nonconforming condition exists if certain non-essential variables are not recorded. As BB say's, poor practice but possibly workable.

Similarly, all Essential and Supplementary Essential variables MUST be listed.