How Weld Inspection can affect Beer Quality by

How Weld Inspection can affect Beer Quality by Wright Gibb and Tim Casper Coors Brewing Company www. coors. com MBAA-RMD Presentation at A-B, Fort Collins May 9, 2007

Sanitary Welding Procedure v Weld test v Autogenous weld v Orbital welding v Sensitization of a weld and it’s heat affected zone. v Filler metal 304 L or 316 L

Roughness Average v Pipe RA v Vessel plate v EP removes up to 30% v Prepping ID of pipe joint.

Magnified surface with stylus

Machined Surface Rolled Sheet Surface Cast Surface

A. W. S. D 18. 1 v Means of visual examination. v Bore scope v Flash light and mirror v Radiograph

A. W. S. D 18. 1 Visual examination acceptance criteria v Welds shall be full penetration. v

Sanitary Weld Specifications AWS D 18. 1 Maximum Allowable Discontinuities Non-Product Contact Surface Maximum Concavity

Sanitary Weld Specifications AWS D 18. 1 Maximum Allowable Discontinuities Non-Product Contact Surface Maximum Convexity

Sanitary Weld Specifications AWS D 18. 1 Maximum Allowable Discontinuities Product Contact Surface -Maximum Convexity

Sanitary Weld Specifications AWS D 18. 1 Maximum Allowable Discontinuities Product Contact Surface Maximum Concavity

Sanitary Weld Specifications AWS D 18. 1 Proper looking weld

Sanitary Weld Specifications AWS D 18. 1 IP: Incomplete Penetration • Travel speed is to fast • Inadequate heat

Sanitary Weld Specifications AWS D 18. 1 IP: Incomplete Penetration • Travel speed is to fast • Inadequate heat

Sanitary Weld Specifications AWS D 18. 1 IP: Incomplete Penetration • Travel speed is to fast • Inadequate heat

Sanitary Weld Specifications AWS D 18. 1 Sugar v. Oxidation during weld process v. Inadequate or no purge of pipe interior with inert gas, such as argon.

Sanitary Weld Specifications AWS D 18. 1 Sugar v. Oxidation during weld process v. Inadequate or no purge of pipe interior with inert gas like argon.

Sanitary Weld Specifications AWS D 18. 1 Concavity (Suck Back) v. Excessive heat purge gas pressure into pipe

Sanitary Weld Specifications AWS D 18. 1 Convexity – Product Contact v. To much filler wire being used v. Rough surface can trap Bio v. Caustic cleaning has trouble getting to all pits and cracks

Sanitary Weld Specifications AWS D 18. 1 Welds shall not contain cracks, undercut, crevices, pits or embedded or protruding material. v. To much weld wire being pushed through weld and burning off inside the pipe

Why do we need to follow Sanitary Weld Specification AWS D 18. 1? The primary reason welds need to be free from defects is to reduce places that Beer Spoiling Organisms can grow. Beer Spoiling Organisms come in various sizes and shapes but generally they are tiny. In an area the size of a dot from a pencil, there could be as many as 40 organisms.

Why do we need to follow Sanitary Weld Specification AWS D 18. 1? Some of the organisms are 0. 7 to 0. 8 um in diameter and 2. 0 to 9. 0 um in length. 0. 7 um equals. 0000276”! Another comparison could be to an average human hair: the size of fine hair is 25 um which is 36 times larger in diameter than some of the organisms!!

Why do we need to follow Sanitary Weld Specification AWS D 18. 1? Beer Spoiling organisms reproduce exponentially. This rapid rate can cause a population explosion down the system from the initial source.

Consequences of Bad Welds Following are some illustrations of how organisms can take root in poor welds

Results of Mismatched Pipe Slow flow Fast flow Pipe Wall Slow flow Pipe Wall Weld Beer spoiling Organisms

Results of IP Cleaning solution Pipe Wall Concentrated organisms Weld

Result of Sugared Welds Cleaning solution Sugared Weld Pipe Wall