Shaft Material
Technical Clarification for Shaft Material of Condensate Extraction Pump:
Subject: Shaft Material Clarification
FEED Requirement: Cl. no. 6.5.7.4 "The shaft, impellers, stationary and rotating wear rings shall be stainless steel. The casing shall be carbon steel. Materials shall comply with API 610 Appendix H, material class S-8."
Explanation: SDC contacted to all reputed suppliers for Condensate pump in Korea & Japan. They have majorly suggested the below mentioned material of construction which is Stainless Steel only as per FEED. Also as per their experience they have supplied same proposed material in numerous projects. SDC also feels that bidders' explanations are reasonable, because SDC also provided similar material for other projects for similar application. Please see the attached drawing for reference.
Detailed Technical explanation: For selection of material of a centrifugal pump shaft, following criteria to be considered:
i) Endurance Limit - as high as possible ii) Corrosion resistance - yes depends on fluid type and contact with shaft iii) Elongation - as low as possible
The endurance limit is the stress below which the shaft will withstand an infinite number of stress reversals without failure. Since one stress reversal occurs for each revolution of the shaft, this means that ideally the shaft will never fail if the maximum bending stress in the shaft is less than the endurance limit of the shaft material. Hence endurance limit shall be as high as possible for better reliability.
Normally endurance limit or fatigue strength is half of tensile strength. Hence if we compare SS 316L & SS 410 tensile strength, SS 410 has better endurance limit then SS 316L.
Corrosion resistance is property to resist material corrosion. As both SS 410 & SS 316L are Stainless steel, both have almost similar corrosion resistivity. This pump is used for the liquid of condensate that is not in condition of corrosion or salinity.
Elongation is a
Subject: Shaft Material Clarification
FEED Requirement: Cl. no. 6.5.7.4 "The shaft, impellers, stationary and rotating wear rings shall be stainless steel. The casing shall be carbon steel. Materials shall comply with API 610 Appendix H, material class S-8."
Explanation: SDC contacted to all reputed suppliers for Condensate pump in Korea & Japan. They have majorly suggested the below mentioned material of construction which is Stainless Steel only as per FEED. Also as per their experience they have supplied same proposed material in numerous projects. SDC also feels that bidders' explanations are reasonable, because SDC also provided similar material for other projects for similar application. Please see the attached drawing for reference.
Detailed Technical explanation: For selection of material of a centrifugal pump shaft, following criteria to be considered:
i) Endurance Limit - as high as possible ii) Corrosion resistance - yes depends on fluid type and contact with shaft iii) Elongation - as low as possible
The endurance limit is the stress below which the shaft will withstand an infinite number of stress reversals without failure. Since one stress reversal occurs for each revolution of the shaft, this means that ideally the shaft will never fail if the maximum bending stress in the shaft is less than the endurance limit of the shaft material. Hence endurance limit shall be as high as possible for better reliability.
Normally endurance limit or fatigue strength is half of tensile strength. Hence if we compare SS 316L & SS 410 tensile strength, SS 410 has better endurance limit then SS 316L.
Corrosion resistance is property to resist material corrosion. As both SS 410 & SS 316L are Stainless steel, both have almost similar corrosion resistivity. This pump is used for the liquid of condensate that is not in condition of corrosion or salinity.
Elongation is a