Stroud Engineers Deliver Major Refurbishment Projects at BMW

Rotec engineers carried out a major refurbishment of the Feed Line and Press at a BMW plant in Gloucestershire.

Over 160 hydraulic hoses on the Feed Line, and 66 hoses on the Major Press were removed and new hoses made and fitted.

This was a challenging job due to the complexity of the machinery and included hoses on the Feed Line HPU (hydraulic power unit), Press and Overload/Protection/Lubrication HPUs. Feed Line Pneumatic cylinders, valves and tubings were also supplied and fitted, in addtion to a total of 48 existing hydraulic cylinders on the Feed Line removed and new cylinders fitted.

Further work taken on the Feed Line, Press and Overload/Protection/Lubrication HPUs included:

  • Draining of the working fluid and cleaning of the reservoir.
  • Replacement of pressure and return hydraulic filters, pressure and return.
  • Replacement of pressure and return hydraulic filters, pressure and return.
  • Resealing of duplex filter block.
  • Removal of existing and refitting of new motor pump sets.
  • Thorough cleaning and inspection.
  • Removal of existing and refitting of new air blast coolers.

All refurbishment works were carried out on time, in budget and to the client’s expectations and standards.

Rotec Deliver Vessel Overhaul at A&P Falmouth

Rotec’s Electrical Mechanical Services team have recently carried out significant maintenance and overhaul works on the vessel Norbay at A&P Falmouth.

Originally built in Rotterdam in 1994, Norbay and her sister Norbank were two of the first of a new generation of ‘super freighters’. The vessel is currently used as a car, passenger and freight ferry in the Irish Sea for P&O Ferries.

Specialists in alternators and generators, Rotec’s Electrical Mechanical engineers have completed a significant overhaul project on the vessel Norbay, on-site at A&P Falmouth. The work included:

  • On-site Aft Bow Thrust Overhaul inc. internal inspection, replacement bearings, rebuild, testing and full works report
  • Port Alternator Clean and Bearing Change
  • Main Vehicle Deck Aft Cargo Fan Overhaul inc. collection from dockside to Rotec workshop inspection, steam clean, re varnish, new bearings, dynamic balancing, testing and reinstall
  • Cargo Fans motors overhaul.

The work carried out will ensure the continued performance and availability of the vessel. Greg Sandy, Business Development Manager and part of Rotec’s Electrical mechanical Services team said:

“Rotec are proud of their strong relationship and partnership with A&P Group in Falmouth, which sees us providing quality services and solutions.

“Our extensive range of services and products, combined with the experience and knowledge of our technical team has given us the well-deserved reputation for being a trusted provider of quality Electrical Mechanical Services.”

Rotec have been trading for over 30 years and take pride in delivering project specific solutions, sustainable results and added value to their clients. For more information on our Electrical Mechanical Services offer, click here.

How to prevent hydraulic oil overheating

Overheating is the second most common issue that occurs in hydraulic systems, behind leakages. Overheating of hydraulic systems is caused by inefficiencies which have resulted in loss of input power being converted to heat. To achieve stable fluid temperature, a hydraulic system’s capacity to dissipate heat must exceed its heat load. Overheating can be avoided by a reduction in hydraulic oil heat load and/or increasing heat dissipation.

Why reduce oil temperature?

Hydraulic fluid temperatures above 82°C (180°F) is likely to lead to oil degradation and cause damage to hydraulic seal compounds. While the operation of any hydraulic system at temperatures above 82°C should be avoided, fluid temperature is too high when viscosity falls below the optimum value for the hydraulic system’s components. This can occur well below 82°C, depending on the fluid’s viscosity grade (weight). To achieve a stable oil temperature, the hydraulic system must be able to dissipate heat faster than it is built up.

Heat dissipation

Heat dissipation occurs in the hydraulic reservoir. Regularly check there are no obstructions to the air flow into the reservoir and that fluid levels are correct.

Heat exchangers

Similarly to the reservoir checks, ensure the core of heat exchangers are not obstructed. Heat exchangers rely on flow-rate, hydraulic oil temperature and coolant in order to disperse heat suitably. It is vital that faulty cooling circuits are replaced. Infra-red thermometers are a reliable way to measure the performance and oil flow rate of heat exchangers.

Oil pressure and leakage

Reduction in system pressure or oil leakage will cause increased heat generation. It is critical that the cause of the leaking is identified and then rectified appropriately. If a relief valve is underneath or positioned too closely to the pressure setting of a pressure-compensator in a closed-centre circuit, it may lead to increased heat generation and the system pressure cannot reach the pressure compensator setting. Subsequently, the component will continue to move oil thorough the system, passing over the relief valve, which produces heat.

Grain ship-loader replacement electro-hydraulic control system

Thanks to the working relationship spanning many years, Rotec were invited to quote for the replacement of the hydraulic power unit and controls of the grain/feed products ship loader travelling gantry system. The client was faced with reliability and obsolescence issues with the original equipment dating back to the 1980s. It is the only plant capable of this function at the port and is in use constantly.

The ship loader hydraulic functions consist of a dual pumping system and associated hydraulic equipment built into an up-cycled twenty-foot shipping container. The container sits on the machine approximately 20 metres above dock level, which presented some unique access issues.

 Based on the original system design, Rotec designed and manufactured a complete self-contained hydraulic system and associated dedicated electrical control panels which control vertical and horizontal movements of the grain conveyors and loading chute to align over the vessel’s holds as required.

The container was specially modified to accept and fit the hydraulic system. This included full sound and fireproofing, internal full bunding and bespoke flooring and ventilation integration. The hydraulic system consists of a primary pump system driven by a 100KW 3300VAC electric motor and proportionally controlled variable displacement pump with a completely redundant secondary backup system in case of partial or total power loss. This 400VAC backup system is supplied from an external generator and is used to recover the chute off a vessel during a power loss when necessary. The main pump systems are supported by cooling and filtration systems and associated electrical control and monitoring equipment which in turn all interface and interlock to the main ship loader external control system.

21The project initially began in 2017, but project was temporarily halted by Brexit and later on, the outbreak of COVID-19. However, following a major fire one evening whilst in use on a vessel which completely destroyed the old containerised system, surrounding cabling and pipework, the project objectives and target completion date was rapidly brought forward to minimize the client’s downtime.

Due to our very flexible approach and ability to respond to an everchanging priorities list, Rotec was able to pick up and resume the build process quickly and managed to complete and factory test the unit ready for site delivery and install by the end of May. Our on-site engineers in the meantime stripped out and replaced large quantities of fire damaged external fixed stainless and special alloy tubing and replaced all external flexible hoses on the machine. The container unit and system were craned into place, pipework connections completed then flushed thoroughly. The system has now finished its commissioning and setting to work process, on time and on budget, and is ready to serve the port for this vital service for at least another 30 years minimum. The client is completely satisfied with the product and service received by him by our team of design, manufacturing, and field service personnel.

 

Propeller Press

A customer who we have a longstanding relationship with requested a propeller press    re-fit for us ein the marine industry.

The customer supplied the framework, into which we incorporated a new valve block, fabricated a weld on bracket for gauge and a pressure relief valve and fit custom made hydraulic hoses as per technical drawings supplied by Rotec.

This bespoke piece of kit is going to Indonesia for use with straightening propeller shafts, to check propeller shafts are true.

Contact us today to see if we can assist you with your fluid power project: sales@rotec.net or 01823 348 900

Date: 8/10/19

Author: Sarka Humpolcova

 

Warship Power Units & Reservoir

After 4 months work replacing hydraulic pipework on a warship, Rotec’s engineers needed to flush the pipes to meet the required cleanliness standards. Due to a change in conditions on board the decision was made to design and build modular bespoke power units and a standalone reservoir.

Rotec have a long history working with the defence industry and specialise in bespoke design and manufacture of hydraulic power units for marine applications, amongst others.

Our team designed and built the power units using 55Kw electric motors close coupled to Berarma Vane pumps and included a flowmeter and a pressure gauge. The Berarma pumps are pressure compensated with variable flow rates. This gives the operators the flexibility to tailor flows and pressures thus ensuring turbulent flow conditions are met to maximise the cleaning action.

Electrical control panels are mounted direct to the trollies to allow ease of use

The power units are fitted with castoring braked wheels for easy manoeuvrability in tight spaces. The Rotec team also designed and manufactured a standalone reservoir, suitable for multiple applications and high volume (fluid) displacement, enabling maximum flexibility as design changes can be incorporated or removed as desired. The system includes pressure return filters which help remove any contaminants from the existing system, ensuring the pipes comply with client specified level of cleanliness.

Rotec delivered to the tight deadline, with just 1 week turnover.

Date: 26/09/2019

Author: Sarka Humpolcova