ASME U Stamp Pressure Vessel Design and Fabrication

PPV CORP is ASME Pressure Vessels Design & Fabrication company, manufacturing pressure vessels used for Oil & Gas, Refineries, Power Plants, Industrial Machinery, Paper Manufacturing, Aerospace, Food Processing, Agrecultural & General-Purpose Industry.

Our manufacturing, fabrication facility is located at 921 Park St, Perris, California 92570 approximately 60 miles east of Los Angeles, Long Beach California, USA. We design and fabricate pressure vessels to customer requirements fully custom design and fabrication to ASME Code Section VIII Div 1. Welders are certified according to ASME Section IX. Material used for fabrication is according to ASME Code Section II. All Non Destructive testing on Pressure vessels is performed accroding to ASME Section V.  

ASME SECTION VIII PRESSURE VESSELS DIVISION 1

This section provides requirements applicable to the design, fabrication, inspection, testing, and certification of pressure vessels operating at either internal or external pressures exceeding 15 psig. Such vessels may be fired or unfired. This pressure may be obtained from an external source or by the application of heat from a direct or indirect source, or any combination thereof. Specific requirements apply to several classes of material used in pressure vessel construction, and also to fabrication methods such as welding, forging and brazing. Division 1 contains mandatory and non-mandatory appendices detailing supplementary design criteria, nondestructive examination and inspection acceptance standards. Rules pertaining to the use of the single ASME certification mark with the U, UM and UV designators are also included.

Vessels Specifications

Design: ASME Section VIII DIv 1
Material: ASME Section II Carbon Steel, Stainless Steel
Welding: ASME Section IX
Non Destructive Testing: ASME Section V

Pressure Vessel Services

* Oil Seperators
* Condensate Receivers
* Waste Traps
* Custom Air Receivers
* Oil Filters
* Knock Out Drums
* Membrane Vessels
* Shell and Tube Heat Exchangers for water, oil and gas

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 ASME Pressure Vessel?

What is Process of ASME Pressure Vessel Fabrication?

A pressure vessel is a container designed to hold gases or liquids at a pressure substantially different from the ambient pressure.

Pressure vessels can be dangerous, and fatal accidents have occurred in the history of their development and operation. Consequently, pressure vessel design, manufacture, and operation are regulated by engineering authorities backed by legislation. For these reasons, the definition of a pressure vessel varies from country to country.

Design involves parameters such as maximum safe operating pressure and temperature, safety factor, corrosion allowance and minimum design temperature (for brittle fracture). Construction is tested using non-destructive testing, such as ultrasonic testing UT, radiography RT, and pressure tests. Hydrostatic tests use water, but pneumatic tests use air or another gas such as nitrogen. Hydrostatic testing is preferred, because it is a safer method, as much less energy is released if a fracture occurs during the test (water does not rapidly increase its volume when rapid depressurization occurs, unlike gases like air, which fail explosively).

In most countries, vessels over a certain size and pressure must be built to a formal code. In the United States that code is the ASME Boiler and Pressure Vessel Code BPVC. In Europe the code is the Pressure Equipment Directive PED. These vessels also require an authorized inspector to sign off on every new vessel constructed and each vessel has a nameplate with pertinent information about the vessel, such as maximum allowable working pressure, maximum temperature, minimum design metal temperature, what company manufactured it, the date, its registration number (through the National Board), and ASME’s official stamp for pressure vessels (U-stamp). The nameplate makes the vessel traceable and officially an ASME Code vessel. Data report typically U1A Data Report can be filed with The National Board of Boiler and Pressure Vessel Inspectors NBBI.

     

What is ASME Code?

The ASME Boiler & Pressure Vessel Code (BPVC) is an American Society of Mechanical Engineers (ASME) standard that regulates the design and construction of boilers and pressure vessels. The document is written and maintained by volunteers chosen for their technical expertise . The ASME works as an accreditation body and entitles independent third parties (such as verification, testing and certification agencies) to inspect and ensure compliance to the BPVC

APPLICABLE ASME CODE SECTIONS IN DESIGN AND FABRICATION OF PRESSURE VESSELS

II MATERIALS

• Part A-Ferrous Material Specifications

• Part B-Nonferrous Material Specifications

• Part C-Specifications for Welding Rods, Electrodes, and Filler Metals

• Part D-Properties

V NONDESTRUCTIVE EXAMINATION
Requirements and methods for nondestructive examination which are referenced and required by other code Sections. It also includes manufacturer's examination responsibilities, duties of authorized inspectors and requirements for qualification of personnel, inspection and examination. Examination methods are intended to detect surface and internal discontinuities in materials, welds, and fabricated parts and components. A glossary of related terms is included.

VIII PRESSURE VESSELS
Division 1 - Provides requirements applicable to the design, fabrication, inspection, testing, and certification of pressure vessels operating at either internal or external pressures exceeding 15 psig.
Division 2 - Alternative Rules, provides requirements applicable to the design, fabrication, inspection, testing, and certification of pressure vessels operating at either internal or external pressures exceeding 15 psig.
Division 3 - Alternative Rules for Construction of High Pressure Vessels, provides requirements applicable to the design, fabrication, inspection, testing, and certification of pressure vessels operating at either internal or external pressures generally above 10,000 psi.

IX WELDING AND BRAZING QUALIFICATIONS
Rules relating to the qualification of welding and brazing procedures as required by other Code Sections for component manufacture. Covers rules relating to the qualification and re-qualification of welders, brazers, and welding and brazing operators in order that they may perform welding or brazing as required by other Code Sections in the manufacture of components. General Welding Requirements; Welding Procedure Qualifications; Welding Performance Qualifications; Welding Data; Welding Forms; General Brazing Requirements; Brazing Procedure Qualifications; Brazing Performance Qualifications; Brazing Data; Brazing Forms.

                   

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