BENDIX TCH-008-014 User Manual

Technical Bulletin

Bulletin No.: PRO-08-14 Effective Date: 3/1/91 Cancels: PRO-08-14 dated 5/30/87 Page: 1 of 1

Subject: Air Dryer Installations and the BX-2150 Compressor

Equipped with the Inlet Check Valve

Contrary to the information reported in the first release of this Bulletin (5/30/87), the
AD-2 and AD-4 should NOT BE INSTALLED IN CONJUNCTION WITH a Bendix
BX-2150 single cylinder compressor when equipped with an Inlet Check Valve (ICV).
Because the AD-9 Air Dryer incorporates an integral discharge line “Turbo Cutoff” valve
this air dryer may be installed in conjunction with a BX-2150 equipped with an ICV.

Field experience along with lab testing has revealed that the BX-2150, equipped with an
ICV, will pass significantly higher amounts oil when an AD-2 or AD-4 air dryer is
installed. The higher oil passing rate can be attributed to the continued “pumping” of air
out the open air dryer purge valve while the compressor is unloaded. This occurrence is
caused by the ICV temporarily assuming the same function as the compressor’s inlet
valve during the unloaded cycle. The lack of head pressure resistance during the
unloaded/purge cycle contributes to the higher oil passing. This same condition does
not exist when the BX-2150 and AD-9 are combined since the AD-9’s integral “Turbo
Cutoff” valve effectively closes the discharge line during the unload/purge cycle. Closure
of the AD-9 “Turbo Cutoff” valve prevents the escape of discharge line pressure and
assures that a positive pressure is maintained above the compressor piston thereby
preventing the ICV from functioning as the compressor inlet valve.

Reference and or mark the following publications:
Product Bulletin PRO-01-33
Service Data Sheets;

SD-01-331 (BX-2150 Compressor)
SD-08-2 (AD-2 Air Dryer)
SD-8-4 (AD-4 Air Dryer)
SD-08-2412 (AD-9 Air Dryer)

Catalog Pages;
01-L-1 to 01-L-16 BX-2150 Compressor
08-A-1 AD-2 Air Dryer
08-A-5 AD-4 Air Dryer
08-A-9 AD-9 Air Dryer
01-A-3 Inlet Check Valve