Structural Welding and Fabrication services

Structural Skid and Pipe Support Services

WELD DESIGN

Engineers typically design welded connections in accordance with the requirements identified in the welding code. The codes address various aspects of the weld. Some of the weld issues specified are listed below

• Groove Welds

• Fillet Welds

• Weld Length

• Complete Joint Penetration

• Partial Joint Penetration

• Lap Joints

• Weld Size

• Weld Spacing

• Transitions

• Static and Cyclical Loading

QUALIFICATIONS

Welding Procedure Specifications (WPS) and Welding Personnel Performance Qualification are required. The qualification covers various aspects concerning the production of welds. Some of these items are listed below:

• Welding Process (SMAW, GMAW, FCAW, GTAW, SAW etc.)

• Base Metal

• Filler Metal

• Preheat and Inter-pass Temperature

• Amperage

• Voltage

• Travel Speed

• Shielding Gas

• Thickness

• Welding Position

• Backing

Requirements for Welding procedure Specifications and Welding Personnel Performance Qualification are identified in the Codes.

FABRICATION AND WELDING

• Base Metal

• Welding Consumables

• Preheat and Inter-pass Temperature

• Stress Relief Heat Treatment

• Backing, Backing Gas, or Inserts

• Welding Environment

• Design Compliance

• Preparation of Base Metal

• Dimensions and Tolerances

• Weld Profile

• Repairs  

Skid and Pipe Support Specifications

Design: AWS Section D1.1
Material: AWS Section D1.1 Carbon Steel, Stainless Steel
Welding: AWS Section D1.1
Non Destructive Testing: AWS D1.1

Non Destructive Inspection on Structural Welding.

* Full or Partial Radiography
* Liquid Penetrant Testing
* Magnetic Partical Testing
* Ultrasonic Testing

What IS NDE?

Nondestructive evaluation (NDE) is a term that is often used interchangeably with NDT. However, technically, NDE is used to describe measurements that are more quantitative in nature. NDE allows parts and material to be inspected and measured without damaging them. Because it allows inspection without interfering with a product's final use, NDE provides an excellent balance between quality control and cost­ effectiveness. Following are some of the main NDE techniques used during pressure vessel fabrication to check weld quality and integrity.

* Visual Testing (VT)

* Full or Partial Radiography (RT, X-ray)

* Liquid Penetrant Testing (PT)

* Magnetic Partical Testing (MT)

* Ultrasonic Testing (UT)

* Pressure Testing (Hydrostatic or Pneumatic)

WHAT IS WELDING?

Welding is a fabrication process that uses high temperatures to melt and fuse parts together. Welding usually also involves the use of something called a filler material, or a consumable. This, as the name suggests, is used to provide a "filler" or pool of molten material that helps facilitate the formation of a strong link between the base metals.
Some of the most common welding processes as:

• MIG Welding - Gas Metal Arc Welding (GMAW)

• TIG Welding - Gas Tungsten Arc Welding (GTAW)

• Stick Welding - Shielded Metal Arc Welding (SMAW)

• Flux Welding - Cored Arc Welding (FCAW)

• Energy Beam Welding (EBW)

• Atomic Hydrogen Welding (AHW)

• Gas Tungsten-Arc Welding

• Plasma Arc Welding

MIG WELDING (GMAW)
MIG welding is one of the easier types of welding for beginners to learn. MIG welding is actually two different types of welding. The first uses bare wire and the second flux core.
Bare wire MIG welding can be used to join thin pieces of metal together. Flux core MIG welding can be used outdoors because it does not require a flow meter or gas supply. MIG welding is usually the welding of choice for DIY enthusiasts and hobby welders who don’t have the money to spend on expensive equipment.

STICK WELDING (SMAW)
Stick welding, also known as Arc welding, is doing it the old-fashioned way. Stick welding is a bit harder to master than MIG welding. Stick welding uses a stick electrode welding rod.

TIG WELDING (GTAW)
TIG welding is extremely versatile, but it is also one of the more difficult welding techniques to learn and are skilled individuals.
Two hands are needed for TIG welding. One hand feeds the rod whilst the other holds a TIG torch. This torch creates the heat and arc, which are used to weld most conventional metals, including aluminum, steel, nickel alloys, copper alloys, cobalt and titanium.

PLASMA ARC WELDING
Plasma arc welding is a precision technique and is commonly used in aerospace applications where metal thickness is 0.015 of an inch. One example of such an application would be on an engine blade or an air seal. Plasma arc welding is very similar in technique to TIG welding, but the electrode is recessed and the ionizing gases inside the arc are used to create heat.

ELECTRON BEAM & LASER WELDING
Electron beam and laser welding are extremely precise, high energy welding techniques.

GAS WELDING
Gas welding is rarely used anymore and has been largely superseded by TIG welding. Gas welding kits require oxygen and acetylene and are very portable. They are still sometimes used to weld bits of car exhaust back together.

WHAT IS WPS?

A Welding Procedure Specification, or WPS, is a document that serves as a guide for the effective creation of a weld that meets all applicable code requirements and production standards. WPS contains details that are necessary to create the desired weld. This includes information such as base metal grade, filler metal classification, amperage range, shielding gas composition, and pre-heat and inter-pass temperatures. The idea is that if a group of welders adhere to all the details on a WPS, they should each be able to produce welds with reasonably similar mechanical properties.

WHAT IS PQR?

The procedures for creating and testing the sample welds, as well as the final results, are documented on a Procedure Qualification Record, or PQR. If the test results are acceptable, the PQR is approved and can then serve as the foundation on which one or more WPSs are drafted. In short, a PQR serves as evidence that a given WPS can, in fact, be used to produce an acceptable weld.

WHAT IS WPQ?

Welder Performance Qualification (WPQ) is performed to determine whether the welder or the welding operator can produce a sound weld or not. Each welder or welding operator shall be qualified for each welding process to be used during production (or fabrication) welding.

The welder is required to weld a test coupon in accordance with the qualified welding procedure specification (WPS), the test coupon is then Radiography/ Ultrasonic or Mechanically tested (as per the requirements of the code of construction). After satisfactory test report the welder may be employed for the production welding (or fabrication welding). Following important factors shall always be considered before conducting the welder performance qualification test.

• Welding Procedure Specification (WPS)

• Welding Process such as GTAW, GMAW, SMAW, SAW

• Size of test coupon, pipe or plate, pipe diameter and schedule, plate thickness

• Position of the test coupon flat, horizontal, vertical, overhead (1G, 2G, 3G, 4G, 5G, 6G)

• Filler metal/Electrode bare, solid, flux core