WPS/PQR

First we will discuss about WPS part than we will come to PQR section 

WPS in simple term is Welding Procedure Specification, actually it basically decide the procedure and way of welding so to achieve the desired property in weld and product.

-actually it defines a single common procedure for all welders, so to weld in that manner to achieve the desired properties

-for instance if in WPS its mention that the weld should be welded in horizontal position and rod should be used for all welding , than it means all the welders have to use the above mentioned parameter

So in nutshell we can define WPS is a written procedure for welding which include essential and non-essential parameter and set the range for those in practical so to achieve the desired properties

For making a WPS, we have to follow certain rules and regulation from a accepted Standard.

The used Standard may be ASME Section IX & EN ISO 15614 ,EN ISO 15609,and so many , it’s also depend on the customers specification and the relevant standard agreed by both manufacturer and customer. 

These  standards present guidelines for WPS format, what variables to include in what range and so many.

Here I will discuss more about ASME section IX requirements and its use in preparation of WPS.

 Below you can see the suggested WPS format from ASME section 9, we will discuss more about that format one by one , we will discuss the specific one related to grove welding , but the same thing would apply to other joints also , just you have to refer the ASME section 9 for other details as similar to presented below

WPS FORMAT -1 OF 2

WPS FORMAT-2 OF 2

OK Let’s discuss the WPS format -

1. Put your company name, welding procedure specification number (ex-1,2 etc.)and supporting PQR no.(we will discuss later)

2. What welding process you are using (ex-FCAW, SMAW etc.) and then type like automatic, semi-auto, manual etc.

SMAW is manual and FCAW is automatic or semiautomatic and so on.

3. JOINTS-what joint you going to prepare –grove, fillet, U grove etc., root spacing etc.

4.BASE material-what base material you are going to weld you must include the P NO. and group no so as to qualified many materials with it ,also mention specification type/grade (for ex-ASTM A216 WCB/WCC etc.)

You should also specifies the thickness range for qualification (min and max) , this you can find this in ASME section IX (QW-450) for groove weld , No. of passes etc.

5.Filler material –for Selection of filler material you must refer the Asme Section II C, The filler material should be of equivalent chemistry and mechanical properties as base metal

 From ASME section 9 you can get F no & A no. in QW-430(ASME SECTION IX). it generally indicates the we don’t need to make WPS for all filler metal hence with the help of grouping we can qualified the other filler metal even its name doesn't listed in WPS but it belongs to same group.

 Size of filler metal –like in case of SMAW 3.2 mm, 4 mm, 5 mm and in case of FCAW- 1.2 mm or 1.6 mm

Weld Metal thickness range –min or maximum of thickness range to be weld should be mentioned in WPS.

6.POSITIONS –WPS must record the welding position 1G, 2G, 3G, 4G etc.,

7. PREHEAT-preheat details must be mentioned in WPS,

8. Electrical characteristics-like type of current and polarity, amps, volts, wire feed speed, energy,tavel speed  etc., mode of metal transfer

9. TECHNIQUE-String or Weave bead, cleaning of weld, contact tube to work distance, multiple or single pass

10. POST WELD HEAT TREATMENT – details of post weld heat treatment like SR, Quenching , Solution annealing

11. Gas details –gasses used for shielding process 

This complete the WPS preparation , if you have any doubt please inbox me i will try to give possible solution 

Next we will discuss about PQR