Processing, August 2019

Figure 4 In a foundry evaluation a casting is filled with weld filler then sliced to yield a bar for bend testing NEW PORTABLE FILLER For Drums and Totes Ruggedly built to fill 55 to 550 gallon containers this machine includes XP controls fume collection adustable feet outrigger stabilizers and fork cut outs front and side AUGUST 2019 www processingmagazine com 29 We also provide installation parts and field service 833 467 3432 specialtyequipment com info@ specialtyequipment com production Many of these applications occur in the arctic regions of Russia and Canada For this service castings are ASME SA 352 Grade LCC while forgings must meet ASME SA 350 Grade LF2 Many products with global use now comply with dual material specifications to meet ASME and European standards For example steel castings are specified and certified to both ASME SA216 Grade WCC and EN 10213 Grade 10619 Emerson often adds its own stringent requirements such as the heat treating of high nickel alloys more demanding chemical composition or special welding procedures In the past Emerson has supplemented conventional ASTM and ASME specifications to achieve the enhanced corrosion resistance levels and high temperature capabilities provided by high nickel alloys This is now accomplished by the new ASTM specification A990 which addresses both material composition and quality Qualifying a foundry As part of a prospective foundrys qualification Emerson inspects and tests Fisher valve castings Non destructive testing radiography is used as a monitoring tool ASTM A990 Class C requires radiography of the first casting of each pattern The acceptance criterion is Level 3 for categories A B and C For categories D through G no cracking hot tears or inserts are allowed as specified in ASTM A990 High nickel alloy castings provide improved performance in corrosive services and elevated temperatures However if high nickel castings are improperly prepared they can pose major problems including poor integrity poor weldability and lower than expected corrosion resistance A systematic foundry qualification process can be followed to avoid these casting difficulties The foundry must cast a 1 inch thick highnickel test plate Figure 4 that meets ASTM Material Specification A990 Its difficult to cast because of the difference in cross section between the base of the weld cavity in the center and the overall 1 inch thickness of the plate The cavity of the poured plate is then filled with a matching composition weld material The welder and procedure for this step must meet the standards outlined in Section IX of the ASME Boiler and Pressure Vessel Code Test bars 3 8 inch thick are cut from the plate and bent over a 1 inch mandrel per ASTM A990 into a U shape The bars are examined closely for cracking along the weld heat affected zone casting grain boundaries or dendrite boundaries Failure to meet quality standards will result in the disqualification of the foundry from further consideration Casting patterns must be dedicated solely to high nickel alloy service Use of carbon steel or a stainless steel pattern is unacceptable due to differences in solidification properties Shrinkage rates for gates risers and other accessories can vary considerably Once the dedicated pattern