Decundi Inspection Services is a Dynamic 3rd party inspection services company which is noted to enact changes to keep up with and implement the requirements associated with the various addendums, changes, and updates of the Codes and Standards that need to be implemented during inspections of Oil & Gas equipment. Decundi have several qualified inspection personnel based in Houston, Texas and throughout the US who are highly skilled in carrying out inspections during Factory Acceptance Testing (F.A.T) of Centrifugal Pumps. Decundi Inspection Services support our clients by way of carrying out inspections during Net Positive Section Head testing (N.P.S.H) of GMC (G-Medium Flow, Closed Impeller) / 9 Stages (Vertical) Centrifugal Pumps and other Centrifugal Multi-Stage Pumps.
Our inspectors carry out witness testing during N.P.S.H testing of Centrifugal Pumps wherein, installation of the GMC (G-Medium Flow, Closed Impeller) / 9 Stages (Vertical) Centrifugal Pumps and respectively, other Centrifugal Multi-Stage Pumps; that the F.A.T of this equipment is carried out independently and the Pump(s) are installed into a pressure vessel which is noted to be an integral part of the flow testing equipment. It is being noted that N.P.S.H test is to measure the capability of Centrifugal Pumps to mitigate and avoid cavitation at the inlet section of the Pump. For informational purposes it is being noted that cavitation occurs when trapped air (air bubbles) are generated at the wetted surfaces of Centrifugal Pumps because of the partial pressure drop of the flowing medium inside the Pump, the effects of which result in a cavity at the affected area of the Pump.
During the process flow, changes occur at the wetted surfaces of the Centrifugal Pump and the pressure inside turns the liquid into a vapor and, as the pump’s Impeller rotates, the vapor turns back to liquid again (refer to air bubbles above). With the disintegration or falling of air bubbles/vapor bubbles, that this phenomenon impinges with the Impeller surface and causes erosion. Additionally, if major cavitation is taking place at the Impeller inlet the performance of the Centrifugal Pump will decrease, leading to failure.
Inspections for Centrifugal Pumps also include verification for the correct material being used for the Shaft, Bell, Bowls, Wear Rings for the Bowls, Wear Rings for the Impellers and other internal components for these Centrifugal Pumps. Also, as a part of the N.P.S.H testing of Centrifugal Pump, Decundi carries out inspection for assurance that after the insertion of the Centrifugal Pump into the pressure vessel, that the water level inside the pressure vessel is at the level stated on the shop router, work instructions, and specification.
For a hypothetical example, Net Positive Section Head testing with a maximum flow of 100 m3/h (1600 l/min) plus bearing run testing and performance testing of Centrifugal Pumps; that Decundi has carried out F.A.T for these Centrifugal Pumps and we verify the Flow Test Points. A hypothetical example could be: Flow Test Points noted to be at 575 GPM, 798 GPM, 1020 GPM, and 1450 GPM and with a Vacuum starting at 4” Hg (mercury) through 26” Hg (mercury), pulled during the F.A.T of Centrifugal Pumps (refer to hypothetical example above).
Decundi inspection personnel carrying out witness testing for Centrifugal Pumps assures that these tests are always carried out with satisfactory results and inspection of this commodity is one of the many offerings of inspection services which Decundi provide to our clients. Please contact Decundi for all of your inspection needs for inspection of Centrifugal Pumps and other commodities for the Oil & Gas and Petrochemical Industry. We have three hundred and twenty (320) inspectors who live at various locations throughout the United States. We also have inspectors in Brazil, Mexico, Nigeria, and Italy.