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Severe service has featured in the Valve program since its early beginnings , and rightfully so . The highly demanding conditions to which these valves are subjected require bespoke solutions with innovative design and / or durable materials . In the Valve World
Conference 2022 , we have reserved a spot for four interesting presentations to whet your appetite .
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As for the terminology , severe service still is highly subjective . Mostly , severe service has been used as a marketing tool to create market demand in the more expensive segment . As with most definitions or categorisations , they are insufficient to cover the complexities of everyday processing facilities . Hazardous media might be a criteria but this also depends of the location in a processing line . Another factor is frequency of use and the application ( on / off , control ). Depending on various criteria , including the ones above , it might be that a standard product will work in a particular service for years without replacement . However , the same valve might fail when process conditions might become more demanding . Some flow control conditions / service applications that are often considered severe include the following : autoclave letdown , boiler feedwater , choke valves , coal gasification , compressor anti-surge , fluids with high outgassing potential , HP separator drains , minimum flow recycle , molten salt or toxic / lethal service . HF alkylation service
The first presentation , by Flowserve , focusses on the material aspect in particular shrinking . The transformation of crude oil into gasoline and other products at a refinery results in numerous types of chemicals , some of which contain molecular chains that are too long to be used directly and must be chemically processed to shorten , or crack , the chains . When some extremely hazardous fluids , such as Hydrofluoric ( HF ) Acid , are processed , additional attention must be given to piping equipment to ensure compatibility with the process media . High-nickel alloys such as M35-1 or Hastelloy are typically used in HF alkylation and because the process to produce these highnickel castings differs from austenitic or ferritic castings , this requires additional quality checks to ensure structural integrity . Recently , M35-1 plug valves which have reliably been used by numerous companies over
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several decades , presented a new irregularity during operation which was immediately addressed due to the hazardous nature .
Shrinkage
During the root cause analysis several Flowserve valves were identified as leaking through the casting wall after a change in the manufacturing process from sand casting to investment casting . Before delivery to the customer , the quality of the castings had been verified through currently accepted practices within the HF Alky industry , including radiography ( RT ) and shell testing specified by ASTM B16.34 . Upon notification of the leaking valves , an investigation was launched in which the original RT process was determined to be unsuitable to provide adequate visibility in the areas of interest . The leaking
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