Valve groups Valve groups control the various hatch cover operations. Good control of the operating speed is essential for the safe movement of high-stowing folding hatch covers. This is particularly important when the hatch cover is near to the open position, where the constantly changing geometry dictates that the speed naturally increases. Effective speed control is also important for side-rolling hatch covers. MacGregor has paid particular attention to this issue and has developed special modularised valve groups for each hatch cover type. The manually-operated valve groups are modular, with cartridge-type pressure and flow control valves. This reduces maintenance costs and ensures that parts can be replaced swiftly as they are available in stock. The ‘block design’ of the control valve has less separate components and connections compared with traditional valve configurations and therefore decreases the probability of leaks and corrosion damage. The valves have a superior flow control feature, which has been designed so that the stroke is long and the control lever makes a large angle at the opening/closing stage, so that a large movement of the lever delivers a small, smooth control change. This makes it easy to control the speed of the motor and therefore the cover(s) at critical stages. The valve group is fitted inside a protection box, with connections for pressure gauges to for system set up. Wireless operation is also available as an option (page 70).
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Pump units Hydraulic pump units are specially designed to function in the marine environment. They deliver oil heating and cooling functions and have optimised tank sizes. The pump unit’s dimensions are often a decisive factor when designing deck storage arrangements. MacGregor understands the need to minimise the use of space and has designed a compact range of pump units. A standard hydraulic pump unit consists of: • Oil tank, the optimal shape of which enables excellent suction and easy connection to motors and pumps • Oil filters, including a large return filter with a visual gauge indicator and an electronic clogging indicator • Oil level indication • Oil temperature indication • Two pumps • Two electric motors: direct on line or soft start • Current indication • Motor overload protection • Oil cooler, including an optional oil cooler that can clean oil with a filter • Oil heating (manual or automatic mode) • Starter cabinet • All adjustable components are easily accessible at the front of the pump unit