Recently Pump Supply & Repair Group were asked to attend the site of a Power Station in London to perform a vacuum test on two Nash pumps. In addition, our scope of work involved confirming the alignment the pump/motor using laser equipment, checking the vibration & bearing noise using condition monitoring equipment and inspecting the internal condition of the pump using an endoscope probe.

Our testing procedure involves fitting orifice test flanges, each with 18 precision cut 'test holes'. A vacuum test gauge is attached to the centre of the plate to record pressure during the blanking off of each test hole in turn.

The performance of the pump was determined by the application of mathematical formulae using the results recorded. A graph is then produced comparing the performance with the OEM catalogue curve, as can be seen in this image.

Further investigation using our endoscope probe revealed that there was significant disintegration and corrosion of the rotor vanes, particularly at the drive end of the pump. An example of this damage can be seen on the attached image, and this almost certainly contributed to the poor performance of the pump.

Our laser alignment equipment indicated the pump to have remained in alignment in the vertical plane, however, it was marginally out horizontally: we proceded to ease the pump back into alignment, aided by the 'live' display given by our equipment which gives a continuously updated display of the alignment. The attached image shows the final alignment report.

Our ultrasonic Condition Monitoring equipment indicated that vibration and bearing condition were all within accepted tolerances.

Visual inspection also revealed on of the mechanical seals to be leaking.

In short we can now Test Pumps up to 300kW and produce a full performance curve INCLUDING power, efficiency and NPSH.

Our New test cell is used to quantify the hydraulic and mechanical quality of our repair and pre-test pumps to determine if work is necessary.

During the last quarter of the year Pump Supply & Repair Group delivered pumps from two of Europe's largest pump suppliers, KSB Ltd and Clyde Pumps (formerly Weir Pumps).

The Horizontal Split Casing unit was a SDBH 300/350 bares shaft pump for a Cooling Water Application at one the country's leading Pharmaceutical Companies,

whereas the two MTC B 50 7 Stage Horizontal Multistage Pumpsets were for Boiler Feed Applications.

Both jobs were closely project managed by the New Pump Sales Team at PSRG to ensure that the both orders were delivered on time and in the case of the Clyde Pump two weeks early.

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The gearbox was delivered to Pump Supply & Repair Group partially seized after running with insufficient lubrication.

At strip down it was also discovered that the main gear hub had fractured

The remainder of the unit had all parts examined for damage and wear with images taken showing the extent of the damage.

The main hub was replicated and the gear ring reconditioned.

During assembly, all parts were set for axial and radial alignment.

Full rebuild completed and the unit was returned to the customer.

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Pump Supply & Repair Group have recently undertaken the repair of a coal ash crusher on behalf of a UK power station. The crusher was found to be in a poor condition after many years of service. Impact damage was found to the rotor hubs which needed to be corrected by carrying weld repairs using stelite impact HS360 rod.

Other areas of concern included wear to the shaft locations and wear to the gland sleeves. these areas were spiral welded and machined. Both gears were also found to be worn with excessive clearance found between the teeth. New gears were manufactured and fitted then new side sections were fabricated and fitted to badly eroded areas.

Internals and externals of the hopper box were grit-blasted. The unit was then rebuilt with new copper bearing assemblies, new sets of packing rings and new gasket & shim sets.

We have modified the main problem area which was the primary cause of bearing failure - gland leakage - fitted new labyrinth seals and large shaft throwers to deflect debris away from bearings.

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Pump Supply & Repair Group were asked to offer advice regarding how to repair excessive corrosion to steel pipework on an exhaust steam manifold from a boiler house without replacing a complex manifold. In December 2008 the inlet flange and 1500mm of the pipe bore was coated internally in situ on site using Belzona 1511 Super High Temperature Metal to recover the surface profile, then coated with Belzona 1391 Ceramic HT Metal.

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Pump Supply & Repair Group have recently refurbished a high temp (650 °C) reactor fan for a major chemical supplier. The failure occurred on site during cold weather, where water-cooled equipment froze during January.

Bearing design was from the 1960's, so this technology was white metal liners inside cast iron water-cooled housings. The units had temperature probes to monitor bearing temperatures.

As can be seen above, the water-cooled bearings have cracked in frost conditions, causing major damage resulting in plant shutdown time and loss of production.

The total fan unit was disassembled, M.P.I. testing of castings was carried out. All water chambers were bead blasted to identify problems at M.P.I. test stage.

Some cast iron gas welding was carried out at our Manchester workshops.

The castings were cold metal stitched. All water chambers coated with Belzona 1341 Superglide. To reduce future scale up problems, the main shaft has been hard chrome coated on bearing areas to original sizes, where the white metal bearings run.

Both white metal bearings were re-lined and bored, scraped to correct fit and clearance. All bearings aligned on site. The fan assembly was balanced to G. 2.5 Dynamic @ 3500 RPM.

The unit was commissioned on site to aid the customer achieve tight delivery schedules.

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Pump Supply & Repair Group are on the move...

This month sees the next exciting stage of growth for our Group, we have now moved to our new purpose built premises, C P House, in Trafford Park, Manchester, doubling our premises space to 32,000 ft².

           Machining Cell

It features:

• 30 Tonne Crane Capacity
• 300 KVA Test Cell Power
• Larger Performance Test Area, incorporating 6,000 gallon submerged & 5,000 gallon head tanks
• 6 metre Borehole Test Facility
• Increased Workshop area and large lifting equipment in all areas
• Grit Blast & Dedicated Belzona Coating Centre
• Fabrication Facility

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One of the two SPP KP15 Cooling Water Booster Pumps supplied in July to a Pharmaceutical Company. The 8" Cast Iron End Suction pumps have a designed duty of 384 m³/hr @ 30m: they were fitted with EFF1 Brook Crompton Motors and spark proof coupling guards.

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Pump Supply & Repair Group has recently undertaken the Belzona application of a Venturi Acid Neutralisation Scrubber. Previously the scrubber had been manufactured from Hastelloy C22 material which was expensive to manufacture and was also still susceptible to corrosion from the media. The customer wanted to change the substrate to carbon steel and apply a Belzona polymeric coating to protect against acid corrosion.

The coating selected not only had to withstand the corrosion properties of the acid but also had to withstand high operating temperature of up to 100°C. While protective coatings can be successfully used at moderate temperatures, migration through the coating readily occurs at temperatures above 90°C. This gives rise to blistering and premature breakdown.

We proposed to apply Belzona 1392 ceramic HT metal to the scrubber By combing a unique blend of inorganic erosion resistant reinforcing agents with a radically new densely cross linked heat resistant polymer. Belzona 1392 provides excellent protection against erosion and corrosion in high temperature environments which has a temperature range -40°C (-40°F) to 200°C (392°F) and a constant immersion temperature of 120°C (248°F).

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