News 1998

Munich, July 1998

Purchasing a Second Hand BAUER Compressor

Does the engine stall? Is the frame corroded? Is the product TÜV-certified? "Unterwasser" highlights some of the criteria that you ought to consider when purchasing a second hand BAUER compressor.

Impromptu dive trips thanks to inexhaustible air supply -your personal compressor unit, stowed away in your garage, helps you realise this dream of unlimited autonomy and adventure. You don't necessarily have to buy a brand new compressor; you might want to go bargain hunting for a second hand compressor. Certain criteria have to be observed.

Visual Inspection

When serviced regularly, a BAUER compressor will stay in good working order for over 30 years. Don't be put off by seemingly a 'worn out' look: even if the paint has come off, the mechanics might still be in perfect condition. Severe corrosion of screw fittings or the filling nozzle indicates 'heavy duty' use at sea, on a boat or in a moist climatic environment. In that case, you ought to ask about the unit's operating environment and the running hours, facts that must be recorded in the purchasing contract.

Security First

Always verify that the seal on the security valve is still intact! The manufacturer has sealed the final pressure valve. If this seal is no longer there, be cautious! High pressure components do not lend themselves to do-it-yourself maintenance work. They are absolutely off limits for laymen. It's equally important that core components, such as the motor, the filter and the automatic condensate drain are genuine BAUER parts. Also the hoses have to be in impeccable condition.

Test Run

The engine's condition is difficult to determine at first sight. Important conclusions about the state of valves, piston rings and cylinder walls can only be drawn by performing a test filling. An empty bottle is connected and the filling time is recorded. If the free air delivery of the compressor is quoted to be 100 litres per minute, a 10-litre cylinder (final pressure 225 bar) out to reach final pressure in no longer than 22 minutes. Minimal variations are normal; strong variations, however, indicate that the unit's general condition is sub-optimal or that the motor rounds (r.p.m.) are lower than required. Perfect operation of the final pressure safety valve and the pressure-maintaining valve is also a sine qua non condition.

Year of Manufacture and Serial Number

	Pricing The compressor's price depends heavily on the unit's condition. A general pricing pattern can't be established. As an indicator, however a depreciation of 15 percent can be assumed for the first year of operation. Another 10 percent can be deducted for the second year. Thereafter a rebate of 3 to 5 percent per annum is appropriate.

The year of manufacture and the serial number must be indicated on the nameplate and must be noted. This information is essential for spare parts orders. The hose's year of manufacture is generally printed on the hose itself and should not exceed 10 years.

Servicing

Compressors have recommended servicing intervals. Occasionally, a TÜV inspection (German inspection authority) may be required. To ascertain whether the required maintenance work has been carried out, several aspects have to be taken into account:

• Did authorised personnel service the compressor? Has the vendor shown you the servicing records in the comp ressor's operating manual and the associated invoices.
• Did the operator receive qualified training from BAUER or an official BAUER service partners? Simply ask to see the course certificate.
• Is the compressor unit, especially the engine and filter, complete and ready to run? Which accessories are included? An automatic condensate drain, electronic control and SECURUS air quality monitoring device.
• Are operating manual and spare parts list included? Can these essential documents be obtained from BAUER?

For commercial use only: has the unit been TÜV-approved? If not, have the appropriate certificates of conformity been included. For units manufactured after 1983, BAUER can supply these documents. Where required, BAUER KOMPRESSOREN can also carry out an on site TÜV examination for second hand units.

Technical Back-up

If you feel uncomfortable checking the stipulated criteria, simply contact an authorised BAUER service partner, who will be happy to help when you purchase a used compressor. They can also assist you with regards to servicing, training and spare parts.

Report: "Unterwasser", issue 7/1998, page 82