Performance Test of Fire Pump for Offshore North Sea Installation

The SPP 18HXB pump is installed on a Oil Drilling & Production Platform 120 miles off Aberdeen in the North Sea.  On the platform the unit operates as a Fire Pump, meaning that the when called upon, effective operation of the pump is critical. The pump was removed from site as part of scheduled maintenance programme, overhauled by the OEM and Pump Group were contracted to carry out a witnessed Performance Test of the unit prior to re-installation offshore. As the whole unit wasn’t removed from the platform, Pump Group had to source the following to facilitate the testing: Headpiece & Discharge Bend Mechanical Seal & Housing Bearing Assembly Bearing Cooling Pipework Headshaft with Sleeve & Bearing Housing Lock Nuts As the site motor was still offshore, a suitable slave motor was selected from PSRG Test stock, in this case being a 1490rpm 250kW flange mounted motor. Prior to the pump arriving at Pump Group premises, our in-house fabricators made a bespoke adaptor piece to connect the test motor to the sourced headpiece. On site the pump has several ‘riser pieces’, which are straight lengths of pipe between the discharge bowls and the discharge head, combining to give tens of metres of pipe between where the water is being lifted from and the motor/discharge head.  To ensure that the operations engineers could calculate exactly what discharge pressure would be available on site, they specified that Pump Group connected pressure tappings directly after the final pump bowl – before any rising pipe – see below image.   On arrival at Pump Group premises, the pump was installed in the test cell below ground tank, LASER Aligned using Pruftechnik Optalign Smart RS ©  equipment, and discharge pipework was fitted including throttling valve & calibrated 10″ flowmeter. Representatives from the client and the Platform Operator attended our site to witness the testing . The pump was run up to speed and a full performance curve was taken from closed valve to the max flowrate. Condition monitoring readings were recorded using Pruftechnik VibXpert II Dual Channel system, and the vibration spectra were reviewed by the client’s engineers. Bearing temperatures were logged throughout the duration of the test using a FLIR T420 Thermal Imaging Camara  connected to data acquisition software on a laptop. The engineers selected several specific “spots” on the pump & motor, and the software then plotted the temperature trends showing the ΔT … Continue reading

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Performance Test on Fire Fighting System Deluge Valves for U.A.E. Oil Platform

In June 2015 Pump Group were contracted to carry out Factory Acceptance Testing (FAT) by a valve manufacturer on a batch of deluge valves prior to their installation on an Oil Platform situated off the coast of Abu Dhabi (U.A.E.). Deluge valves are an integral part of Fire Protection Systems located in high risk areas such as Offshore Platforms and Oil Refineries. They are designed to be installed into the Deluge Sprinkler System and as soon as a fire is detected the deluge valve actuates and allows a massive volume of water to surge through to the sprinkler heads. The deluge valves are unlike normal mechanical valves in that they use pressure differentials across the valve and the flow of water to fill a kevlar bag inside the valve which then, due to the unique shape of the internals, uses the water pressure to hold the valve shut. The Platform Operator specified that full performance testing of the valves had to be carried out at substantial flowrates across a range of inlet pressures replicating any possible site conditions that the valves may be required to operate under. The valves had to be tested to check that they could fully actuate open and closed at pressures of up to 15 bar. In addition to this, hydrostatic tests were carried out on the valves to ensure the integrity of the units. A test system was designed using our 250kW 2900rpm motor and a suitable split case pump was selected – capable of 19 bar pressures at flows in excess of 300 m3/hr. Valves were required up & downstream of the deluge valve being tested to allow engineers to carry out hydrostatic tests directly after the hydrodynamic flow tests. Representatives from both the Valve Manufacturer and the Platform Operator were in attendance for the testing of the valves – 6″ and 8″.  Pump Group Engineers performance tested the 8″ valve first: pneumatically actuating it open and closed at a range of pressures up to 15 bar, and then hydrostatically testing the valve to the required 19.5 bar. Using variable speed inverter drives in tandem with an additional gate valve downstream of the deluge valve, Test technicians were able to achieve a range of pressures from 5 – 15 bar all at the same flowrate by adjusting the pump speed and throttling the discharge valve. The 8″ valve was then replaced by the 6″ … Continue reading

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Repair & Performance Test of a 26/24″ Vertical Split Case Pump

The 6 tonne Mather & Platt 26” / 24” Lonovane Split case pumps were removed from site after failure, and sent to Pump Group with the remit of carrying out a full overhaul and performance test. The units are used on site at a Coal Fired Power Station drawing water out of the nearby river to be filtered and then used as cooling water for the power generation process. The site normally has 4 pumps installed including one standby. Two of these pumps had both failed within a short period of time meaning that the site was close to a shutdown scenario should anything happen to either of the remaining units. On receipt at our works the units were cleaned and disassembled and the causes of failure determined. On one unit the shaft had sheared and on the other the upper thrust bearing had failed. On both units this meant the rotating element was able to drop and therefore impact and run against the lower neck ring. The seal mounting sleeves, roller bearings & intermediary make-up sleeves were all damaged beyond a repairable state. New parts were reverse engineered in-house out of Stainless Steel. The mechanical seals were also replaced with new. Several areas including the cutlass bearing holder and the bottom housing were also rebuilt with Belzona 1111 (Super Metal) which was then machined to size. Belzona Polymer 1111 is a solvent free epoxy resin reinforced with silicon steel alloy which makes it ideal for this application.This was a quicker and more cost effective alternative to completely reverse engineering the damaged areas. New shafts were machined from EN24T and the impellers were re-ringed to reduce the wear ring clearances to within tolerance. The rotating element was then built and dynamically balanced to G2.5 at 1000rpm. After assembly, the unit was hydrostatically tested to 1.5 times working pressure. The units are be run in a vertical orientation on site so to enable testing a motor stool plate was manufactured to allow one of the test stock 250 kW motors to drive the pump. A motor stand to support the weight of the motor was also fabricated and used on test. The unit was placed in our Performance Test Cell, laser aligned to one of our 250 kW motors and performance tested. The units underwent detailed vibration analysis using Pruftechnik VibExpert system and a performance test report was produced and issued to … Continue reading

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Crude Oil Booster Pump – 60Hz Performance Test For North Sea Oil & Gas Client

Industry – Oil & Gas A Crude Oil Booster Medivane Split Case pump was suffering operational issues where it was installed offshore. The pump was removed by the operator and returned to the OEM for overhaul. We were contacted by the pump OEM to test the performance of the unit post refurbishment ahead of its return to a North Sea Oil Field installation within a 2 week window. Inside this timescale the unit was installed & Laser Aligned in Pump Group’s test facility, commissioned ahead of testing, operated during a 4 hour Customer Witnessed Test Session to confirm performance at the site operating conditions. The test circuit was artificially heated and maintained to 50°C for the duration of the test. We also utilised our positive pressure system to provide an additional 0.5 bar pressure to the suction tank, and our installed duplex filter system allowed us to carry out the extended duration test whilst keeping the filters clear. In addition to the pump performance test report, a mechanical report was prepared which included the bearing temperatures recorded throughout the duration of the test, and once the pump temperatures had stabilised, condition monitoring readings were taken using Pruftechnik Vibscanner equipment and a detailed vibration analysis report was issued. The test was only made possible by the support of Pump Group’s manufacturing and fabrications teams, allowing in-house modifications to critical components during the installation and setup. Following testing the unit was returned to the North Sea installation and has been successfully installed and is in now in operation. Working to such a critical deadline Pump Group was able to rely on strong working relationships with key suppliers to source parts required for testing from across the UK and Europe, with a coupling being sourced from John Crane in Czech Republic, couriered to Pump Group in Trafford  and machined, all within 48 hours, to allow testing to be completed on schedule. Further to the successful completion of this testing for the Pump OEM, Pump Group have just received confirmation of more orders for Performance Testing in the coming weeks. For more information on our Performance Test Cell, or to discuss how our test facilities can be of use to you, please contact our Test Manager James Pendleton-Briers on 0161 864 4678 or via jamespb@pumpgroup.co.uk.  

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Critical Turnaround 350kW Fan Repair & Test

Industry – UK Flooring Manufacturer Our client reported concerns on operations of a large extraction fan, one of our External Sales Engineers attended site to assess the situation & take condition monitoring readings which confirmed vibration was at unacceptable levels and advised that the unit was removed for overhaul. The unit is the sole extraction fan weighing 5 tonnes for a flooring production factory which couldn’t operate safely without the fan in use. The plant was therefore shutdown until the fan could be reinstalled. The Condition Monitoring analysis determined that both the motor and fan bearings were not showing any signs of damage – the vibration was propagating from the impeller end of the fan. Given the criticality and short timescale of the repair, the overhaul of the rotating element was undertaken to cure the vibration issue. The fan was delivered to our workshop facility and the front cover was removed to find that the impeller was fractured on the front shroud. Closer inspection identified further cracking and fractures on the impeller vanes. The impeller was separated from the shaft, pressure cleaned prior to MPI testing. Magnetic Particle Inspection was carried out on the impeller which located over 80 further faults to the welds & blades of the vanes. All cracks were then terminated by a drilled hole to stop the crack from propagating prior to the welding of the blades.  The rotating element was then dynamically balanced to G2.5 @ 1450rpm. The impeller was re-drilled and the covers were refitted with a new seal which had been specified to suit the 250 °C operating temperature. The unit was painted internally & externally, the fan reassembled & the unit placed in our test cell where the motor & fan shafts were LASER Aligned to minimise vibration. The 350kW motor was connected to our Control Panel Inverter and the unit was run up to full speed witnessed by our client. Once bearing temperatures had stabilised full condition monitoring results were taken. Vibration had reduced from RMS values of over 10mm/s to below values below 1.5mm/s. The time taken from the unit arriving in our workshop to it being back on site was less than 3.5  days. After delivery of the fan to the clients premises, our engineers attended site to carry out Laser Alignment of the fan drive to the motor before the unit was commissioned. The unit has run on site … Continue reading

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6.5 Tonne Split Case Pump Repair for Chemical Plant

Industry – Chemical Production Two 6.5 tonne Mather & Platt 28” / 22” Split case pumps were removed from site as part of planned maintenance, to carry out a complete overhaul. All bearing, shaft diameters and housings were checked and found to be within tolerance for their respective class of fit. The white metal bearings were re-lined for re-use. Further out from the journal diameters there were deep marks due to action from the seals and baffle plates.  We undercut the markings and rebuilt with Belzona 1131 Bearing Grade® polymer and machined to OEM specifications. Damage from Off-Axis running was present in both DE & NDE Bronze bearing shells. This was remedied by white metal lining the shells then boring to original dimensions. The top & bottom halves of the volutes were generally in good condition, but with internal surface scaling present.  The internals were grit blasted to surface profile specification SA2.5 and 2 coats of Belzona 1341 Supermetalglide® were applied. Belzona 1341 Supermetalglide® was selected as it improves pump efficiency by using hydrophobic technology to repel process fluids and reduce turbulent flow, lowering energy costs. The units underwent seal conversions top AES Split Cartridge Seals with Silicone Carbide running faces and LabTecta® Push-Fit bearing protectors. The Stainless Steel impeller was in good condition with only superficial markings. The impeller was dynamically balanced at 1000rpm to G2.5 prior to reassembly. After assembly, the split case pump was hydrostatically tested to 1.5 times working pressure and was placed in our Performance Test Cell, laser aligned to one of our slave motors and performance tested. The units underwent detailed vibration analysis using Pruftechnik VibExpert system and a performance test report was produced and issued to the customer. The units had been made redundant several years earlier, and had been sat dormant since then. Plant cooling water requirements changed and Pump Group were able to refurbish and modernise the pumps within the clients’ budget.  The unit was returned to site within the allowed time frame to meet customer requirements. For more information on how we can utilise our extensive workshop and testing facilities to assist your company with your operational needs, please contact a member of our Repairs Team on   +44 (0)161 864 4678 or via repairs@pumpgroup.co.uk.

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Liquid Ring Vacuum Pump Repair – Food Industry

A team of our Site Services engineers attended site and carried out an endoscopic inspection on the Vacuum Pump.  After reporting on the findings, the decision was made for our site team to remove the unit and transport it back to our workshop facility for disassembly and further inspection. Upon stripping, it became apparent that there was substantial damage to the internals of the pump. The endplates and rotor were scored heavily. The gland seals were worn and the gland locations needed rebuilding. The bearings were stripped and condemned because of contamination. When measured, both bearing housings were oval shaped and outside tolerance. The pulley was found to be in poor condition and we recommended fitting new. The packing sleeves were grit blasted and rebuilt with Belzona 1131 Bearing Metal. We machined the rotor, the endplates, the body length and O-rings were machined to maintain the OEM tolerances. The damaged gland areas were rebuilt with Belzona 1131 and machined to size. The bearing housings were metal-sprayed and new bearings & consumables were supplied. A new pulley was supplied and fitted to prevent belt slippage.  The pump was assembled vertically to achieve correct clearance and then pressure tested. The unit was then fully performance tested in our test cell, and at 480mbar the pump achieved 9400m3/hr discharge volume.  The Pump was spray painted, and underwent final inspection prior to being transported back to site by our transport. Our site service engineers then installed and commissioned the unit. The unit was removed, refurbished, tested and installed and commissioned all within the time-frame allowed by the customer and within budget. As Rotating Equipment Specialists, Pump Supply & Repair Group is the one stop shop for all of your mechanical needs. For more information on how PSRG can assist you in your operational requirements, please contact our Operations Director, Martin Cooper at mcooper@pumpgroup.co.uk or on 0161 864 4678.

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