Parker HDK-CNG Series Operating Manual

Contents

Parker HDK-CNG Series Operating Manual Manual pdf 43 page image

Maintenance and repair of the dryerHDK-CNG_EN_03_2016 43Component Maintenance task to be carriedMaintenance intervaldailyweekly12 months24 monthssee pageSensor of optional dewpoint-sensing control systemReplace.   Check valves Clean, replace if necessary.  47Solenoid valves Valve bodies and purging - clean and replace ifnecessary.    47Dust sieves, gaskets, drying agent Replace.     47Pre- and after-filter Check differential pressure on the upstream anddownstream filters.    45Change the element.    46When carrying out any maintenance work, comply with the following safetyinstructions:Danger!There is a very considerable risk of personal injury, when carrying outwork on the activated and pressurised dryer.Before commencing any maintenance tasks always shut down the dryeras described on page 39, Depressurise the dryer and shut it down!Before working on dryer, first purge the system with inert gas anddepressurise it.On no account place the dryer into service or take the dryer out of servicewithout inerting it beforehand!Together with air, gaseous methane can form an explosive gas mixtureand therefore poses a considerable danger. An explosive atmosphere canbuild up during maintenance work especially when replacing the dryingagent. To avoid this, the dryer must be purged with inert gas both beforecommissioning well as before taking out of service.You will find information on inerting on Page 15.Making preparationsMake the following preparations before starting maintenance work:► Purge the affected section of pipework and the dryer with inert gas.► On ATEX-compliant dryers:Cancel the Ex-zone (in acc. with owner's operating instructions).► Block gas supply to the dryer.► Depressurise the dryer.► Allow the dryer to cool down.Then start work - not before this point!