AWS D18.3-D18.3M pdf free download
AWS D18.3-D18.3M pdf free download.Welding of Tanks, Vessels, and Other Equipment in Sanitary (Hygienic) Applications.
3. Definitions
Welding terms used in this specification are defined in AWS A3.O, Standard Welding Terms and Definitions. Other terms not defined in AWS A3.O are defined in this section.
Contractor. Includes manufacturers, contractors, subcontractors, fabricators, erectors, or other organizations that fabricate weidments that are intended to meet the requirements of this specification.
essential variable. A variable in which a change beyond that described in 4.1.5, Welding Variables, is considered to affect the mechanical properties of the weldment, and shall require requalification of the Welding Procedure Specification (WPS).
nonessential variable. A variable in which a change, as described in 4.1.5, Welding Variables, may he made in the WPS without rcqualification.
nonproduct contact surface (NPCS). A surface other than a product contact surface.
overlap. The protrusion of weld metal beyond the weld toe or weld root.
Owner. Organization that will operate the sanitary (hygienic) processing system, or the organization’s authorized representative.
pit. A surface imperfection the depth of which exceeds 25% of the smallest surface dimension, and whose length does not exceed three (3) times its width.
product. Any material in any form (liquid, powder, solid, slurry, etc.) for which the tank, vessel, or other piece of sanitary equipment is designed to store, contain, or process.
product contact surface (PCS). Any surface that is exposed to the product or any surface from which materials may drain, drop, or he drawn into the product.
surface classification zones
Zone I: Product Contact Surface (PCS).
Zone 2: Nonproduct Contact Surface—Exposed (NPCS-E)—beyond the normal PCS where normal operations (i.e.. draining, filling, etc.) pose a significant risk of incidental contamination.
4. Qualification
4.1 Procedure Qualification
4.1.1 A written qualified Welding Procedure Specification (WPS) shall be followed for each weld in sanitary applications. The welding procedure specification may he in any convenient format provided all the welding variables of 4.1.5, Welding Variables, are recorded. A sample WPS form is shown in Annex C.
4.1.2 The welding variables required to be addressed for each procedure shall be those specified in 4.1.5.
4.1.3 The evaluation of procedure qualification test weldments shall be as listed in 4.1 .3.1 through 4.1.3.4. The actual welding variables used during the qualification tests shall he recorded in addition to the results of the destructive and visual examination. The welding procedure qualification record may be in any convenient format provided all the welding variables of 4.1.5, Welding Variables, and the results of all tests are recorded.
4.1.3.1 Procedure qualification shall he by standard test weidment as required in AWS B2.1, Specification for Welding Procedure and Performance Qualification, except that the essential and nonessential variables of 4.1.5 apply.
4.1.3.2 Procedure qualification test weidments shall he visually examined on all surfaces.
4.1.3.3 The destructive test sample preparation shall be as required in AWS B2.l, Annex II, except that bend specimens shall not he machined flat. The maximum radius at the edge of the bend specimens is 1/16 in 12 ininI.4.1.3.4 If any test fails, the procedure fails, and a new welding procedure qualification test shall be conducted.AWS D18.3-D18.3M pdf download.
