Documents are only to be used and distributed completely and unchanged. It is strictly the users’ responsibility to check carefullythe validity of this document with respect to his product. Manual-no.: 999164 / 19/05/2009page 55 of 75Replacing diaphragms and valvesAll bearings are encapsulated and are filled with long-life lubricant. Under normaloperating conditions, the pump is maintenance free. The valves and diaphragms arewear parts. If the rated ultimate vacuum is no longer achieved or in case of increasednoise level, the pump interior, the diaphragms and the valves must be cleaned andthe diaphragms and valves must be checked for cracks or other damage. Depend-ing on individual cases it may be efficient to check and clean the pump heads on aregular basis. In case of normal wear the lifetime of the diaphragms and valves is >10000 operating hours.- Prevent internal condensation, transfer of liquids or dust. The diaphragm andvalves will be damaged, if liquids are pumped in significant amount.If the pump is exposed to corrosive gases or vapour or in case of deposits, mainte-nance should be carried out frequently.- Regular maintenance will improve the lifetime of the pump and also protect bothman and environment.Ensure that maintenance is done only by suitable trained and supervised techni-cians.☞ Ensure that the pump cannot be operated accidentally. Never operate the pumpif covers or other parts of the pump are disassembled. Never operate a de-fective or damaged pump.☞ Before starting maintenance isolate the pump from the electrical supply andwait two minutes after isolating the equipment from mains to allow the capaci-tors to discharge. Avoid the release of pollutants. Allow sufficient cooling of thepump.• Attention: The pump might be contaminated with the process chemicals that havebeen pumped during operation. Ensure that the pump is decontaminated beforemaintenance and take adequate precautions to protect people from the effectsof dangerous substances if contamination has occurred. Ensure that the mainte-nance technician is familiar with the safety procedures which relate to the prod-ucts processed by the pumping system.• Wear appropriate safety-clothing when you come into contact with contaminatedcomponents. Avoid the release of pollutants.Before starting maintenance vent the pump and isolate it from the vacuum system.☞ Please read section ”Replacing diaphragms and valves” completely beforestarting maintenance.Partially the pictures show pumps in other versions. This doesn’t influence replacing diaphragms andvalves of the pump.Set of seals for ME 4C NT VARIO ..............................................................................................696864Set of seals for MZ 2C NT VARIO / PC 3002 VARIO ..................................................................696869Set of seals for MD 4C NT VARIO / PC 3003/3004 VARIO .........................................................696870Set of seals for MV 10C VARIO-B / MD 12C VARIO-B / PC 301x VARIO .................................696821Diaphragm key (w/f 66) ...............................................................................................................636554NOTICENOTICE