Guide reading welding procedure Specification WPS (Welding procedure Specification)
I. Introduction - Purpose - requirements:
- Welding Procedure Specifications is table work instructions to perform 1 weld of fabrication prescribed. To make a weld meet the specifications, the welder must know, understand and comply with technical welding processes.
- This document is intended to provide guidance for welders to understand and comply with the welding process, avoid technical errors, minimize welding defects, limiting bending deformation, understand correct welding method applied in accordance with process, material type, thickness, diameter, requirements for heating, gas welding, welding medicine, welding rod type, current, welding speed, oscillation welding, electricity connection, dimensional electrodes, weld assembly ...
- Support QC Welding, weld Formen, welding engineers monitor the production process and quality correct.
Welding processes - technical parameters:
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| eg : Piping welding procedure specification (1 of 2) |
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| eg : Piping welding procedure specification (2 of 2) |
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| eg : Structure welding procedure specification |
Above are some welding procedure specification for structural and pipe welding in a oil & gas projects in general, and in the field of industrial engineering.
Explain :
· Welding Procedure Specification : WPS
· WPS no : Welding Procedure Specification number ( Ex: P05 is WPS for piping welding process number 05, S06 is WPS for Structure welding process number 06)
· Revision No : A or B or 0,1,2,3...
· Date : date of issue process
· Page:
· Client :
· Project :
· Supporting PQR No : WPS follows PQR Number ...( Ex: WPS001 follows PQR Number 001, PQR is Procedure qualification Record )
· Description of process : Ex ( SMAW, GTAW….)
· Description of impact property :
· Weld code : ( ASME IX, AWS D1.1,DNV ….)
A. Base metal
Eg pipes, steel V, steel I, fitting ...
- Material specification: type of material (eg A333, A106, A312 ...)
- Code classificasion: standard materials, material groups (eg P8 Group 1, P1 group 1 ...)
- Thickness: Material thickness applied
- Diameter ranger: Diameter materials applied
B. Welding Material
- Process : The method weld (eg GTAW tig welding methods, SMAW, saw ... , I will introduce later in the article)
- Specification SFA no :Standard welding rod ( eg : A5.18, A5.28, SFA 5.18…)
- AWS classification : Specifications welding electrodes ( eg : E7016, ER- 70s, E8016….)
- Manufacturer : ( eg :Kobecol, Lincold, Huyndai…)
- Electrode filler trade name : ( eg : LB52-U, LNT-26….)
- Electrode diameter : ( eg diameter : 1.6, 2.4, 3.2, 4.0 ...)
- Torch Gas : ( eg : Argon 99%, Co2 99.2 %...)
- Flow rate : weld gas flow rate ( 10-25 L/min)
- Backing Gas : weld gas inside pipe helps prevent the antioxidant
- Non consumable electrode : type of electrode ( eg :EWHT-2…)
- Non consumable electrode diameter : eg (1.6,2.2,2.4….)
C. ELECTTRICAL CHARACTERISTIC/ TECHNIQUE
Part number: weld classes (eg: root, hot, fill , cap )
- String / weawe technique: The oscillating arc weld
- Weld bead: oscillating weld width
- Current - polarity: Electrodes used (DCEN -, DCEP +)
- Cup size: weld ceramic cup sizes (6,7,8,9 ...)
D. JOINT DETAIL PASS SEQUENCE AND ELECTRODE SET UP
- Pass number : root, hot, fill, cap
- Position Qualified : eg (1G,2G,3G….
- Verticcal welding progression : (Uphill , Down : )
- Root gap : Weld gap ( vd: 2-5 mm)
- Root face : eg .. 0- 2 mm (Thickness the edge)
E. WELD TEMPERATURE
+ The Preheat : Preheat is required when weld thick connections, or weld of alloy steel, weld fabrication will start only when the temperature reaches a minimum sufficient.+ Preheat works to reduce the cooling rate of weld metal and heat affected zone of base metal, reduces the shrinkage of the weld, reducing residual stress, avoid cracking ...
+ Thickness <19mm often does not need to be preheat, but must be heated to 38 degrees C when surface material has water (code required). (Eg : 19mm <t <38 mm = 66 degrees C or 79 degrees C ...)
- When repair welds : need added heat + 50%
- Weld heat measurement methods: (Method of checking)
- Tempilstik: pen try heat
- Pyrometers: Heat gun
F. POST WELD HEAT TREATMENT
- PWHT requitred if t> 19.5 mm. Temperature Incubation after welding- Method of tempering, incubated furnace annealed, electric sewing springs, Temperature torch ...
G. Welding parameters
Amperage, Voltage , T.speed ( weld speed)H. Prepare By… Review By…. Approve By
- Prepare by : person making process- Review By: person verified
- Approve By client
- Approve by CA : Approved by the registry