VALVE MAGAZINE Fall 2024

ADDITIVE MANUFACTURING CASE STUDY

Implementation For series manufacturers, it makes little sense to assess conformity based on single unit verifications (Module G) with a Notified Body due to the amount of work and money to be invested. Even small production series are econom ically viable if the additively manufactured version is designed for the same category as the traditionally manu factured version. For initial certification, SAMSON decided to qualify its Type 3251 high-pressure valve, which is well established on the market, in an additively manufactured Type 3251-AM version. The standard version of the Type 3251 valve is available in DIN and ANSI sizes from DN 15 to 500/NPS ½ to 20 and in

In addition to nondestructive testing, special attention was paid to the destructive testing of specimens taken from the initial samples at different positions. Samples were taken at areas that are critical in additive manufac turing (such as critical overhangs) and at different manu facturing heights. The initial sample test results were compared to the side samples on the printing plate and the material spec ifications for the printed material; assessments were performed accordingly. At the same time, guidelines, documented procedures, work and testing instructions as well as protocols had to be defined and implemented for the equipment made from

pressure ratings from PN 16 to 400/CL 150 to 2500. The Module H conformity assessment procedure was applied to the Type 3251, which covers pressure equipment up to hazard classification in Category III. Consequently, the same Module H conformity assessment procedure was performed for the new Type 3251-AM, which is available in valve sizes up to DN 100/NPS 4 and pressure ratings up to PN 400/CL 2500; the equipment was certified by TÜV-SÜD Industrie Service GmbH (Notified Body no. 0036). Conformity assessment covers design, manufacturing and testing. In addition to the risk and hazard assessment performed for this valve type and the associated strength calculations with higher safety factors, SAMSON drew up comprehensive inspection and test plans for initial sample and pilot lot qualifica tion. These ITPs served as guidelines for inspection of the blanks, finished parts and the completed valve assembly. In addition to strength calculations, the following was comprised: • FEM and CFD simulations • Destructive testing of side samples and initial samples • Nondestructive testing of initial samples and pilot-lot specimens • Dimensional inspections of blanks and finished parts as well as ready-assembled valves • Function tests, leak tests, seat leakage tests and hydrostatic strength tests • Flow rate and sound pressure level measurements at higher pressure drops • Inspection of manufacturing requirements and markings • Inspection of test documentation

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FALL 2024

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