SECURING A LIFT SYSTEM IS ESSENTIAL IN ORDER TO ENSURE THE USER’S PHYSICAL INTEGRITY AND THE SERENITY OF ALL COMMITTED PARTIES WITH LEGAL LIABILITY FOR THE SAFETY OF THE LIFT SYSTEM: the owner or his legal representative (for example the building manager), the maintenance technician, the notified body in charge of the periodical inspections (in particular, the technician signing the audit trail), the installer and the manufacturer.
The statistics on lift system accidents of the last 40 years prove that hydraulic lifts are safe systems. In this respect, GMV S.p.A. is a living example, with about 800,000 hydraulic groups sold all over the world in almost 60 years. It is not to forget though, that these products are subject to wear, tear and material fatigue. This is why controls and revisions are necessary.
In recent years, we observe an increasing interest in safety matters in any field. Experience demonstrates the presence of potential risks ignored in the past, but nowadays, great importance is given to the prevention of accidents. Public opinion is getting more than ever interested in the safety issue.
The Machinery Directive 2006/42/CE specifies that “the machinery has to be designed, constructed and, if necessary, equipped with safety devices in order to exclude uncontrolled movements of the car in the downward and upward travel” (6.4.1.).
Following recent regulations, these safety measures have to apply to the lift sector as well. In fact, the amendment A3 to the standards EN 81-2, entered into force on 01/01/2012 and now integrated in the standard EN 81.20, requires that safety devices must be installed in new lift systems, in order to prevent uncontrolled movements of the car with open doors.
The compliance with this standard has found concrete application with the introduction of the redundant safety lock on the hydraulic valve block.
This regulation has been extended on existing lift systems as well, through the standard EN 81.80 which was first published in 2003, classifying as “high” the risk of uncontrolled movements of the car with open doors.
Since this topic is always a current issue, the CEN (European Committee for Standardization) updated this issue in June 2016 with a new version of the standard EN.81.80 (pr EN 81-80:2016), which contains the particulars of the recent standard EN 81.20.
The standard EN 81.80 may be used as a guideline for:
- Lift owners wanting to comply with their legal responsibilities, as required by standards in force
- Maintenance companies and/or inspection bodies in order to inform lift owners about the safety level of their lift systems
It is worth considering that elevators are absolutely one of the most used means of transport in the world, and one of the oldest still in use: Of about 2 million hydraulic systems in service, about 20 % (400,000) are older than 25 years. Many lift systems actually in use don’t even guarantee the safety level (even though precaution rules and common sense should impose it) that is required for new lift systems by the amendment A3 to the standard EN 81-2.
THERE ARE OBJECTIVE REASONS TO SECURE OLD HYDRAULIC POWER UNITS and assure all lift passengers the same sense of safety, regardless of the age of the lift.
REDUNDANT SECURITY LOCK
Old hydraulic elevators usually are not equipped with a redundant security lock and in some cases even without a shut-off (locking) device.
For hydraulic elevators installed before 2012, a double security was provided only by the shut-off valve (shutter) and the releveling system. It is therefore obvious to what degree the safety of a lift is compromised when, due to a failure in the flow block system, the releveling system stops working after 20 minutes due to an overheating of both engine and oil. In consequence, the double security is no longer operational, and this can cause an uncontrolled movement of the car with open doors.
The same situation may occur in case of power failure, which would cut off both the engine and the releveling system.
The DLV valve introduces the redundant security lock for valves produced by GMV or by other manufacturers. It is an electrically operated non-return valve, installed in series between the piston and the main distributor.
It is possible to install the DVL valve in less than two hours.
VALVE CONTROL BLOCK CHECK
General periodic checks of the valve control block are necessary. GMV is able to offer this service for both the valves and the complete power units in its own plant in Novara.
Hydraulic oil wears out after years of use and needs to be replaced. In compliance with the recent environmental protection standards, it is recommended to replace the mineral or synthetic oil by biodegradable Ecological Fluid. The GMV Ecological Fluid is a synthetic based hydraulic fluid with a biodegradability index of >70 %. In case of accidental spilling, the owner of the system is protected from any penal consequences.
GMV considers its duty to inform customers in this respect and to sensitize all interested parties. For this reason GMV has organized and plans to organize in the future training units for lift operators, verifiers from notified bodies and building managers on this topic.
GMV provides suitable products to meet this demand at low costs.