QT-7.5 Air Master
Quincy Compressor
50121M201, May 2001
1
3501 Wismann Lane, Quincy IL 62305-3116
INTRODUCTION
This manual provides information for the Model QT-7.5
reciprocating compressor, per Record of Change 201.
The Model QT-7.5 is an aircooled, two stage, two cylinder,
pressure lubricated compressor, with up to 175 p.s.i. continu-
ous pressure capability. It has a 4.5" low pressure bore and a
2.50" high pressure bore, with a 3" stroke. This compressor can
be run at 500-1060 r.p.m.
A hooded air filter/silencer is available as an option, as well
as head unloaders.
CHANGES
since previous printing dated September 1998:
Added crankcase lubricant capacity.
Changed to heavy-duty type head bolt washer.
Added intercooler replacement kits.
Changed tank drain valve from cable operated to ball valve
operated.
Changed throttle control on engine driven units to bullwhip
cable style.
Changed Kohler engine driven base units from head
unloader style to discharge line unloader style.
Change bearing carrier and cylinder/crankcase bolts to use
new type bolt with pre-applied sealant
Crankcase was modified to accept 3/4 npt pipe plug or 3/4
npt low oil level switch.
TABLE OF CONTENTS
Model & Serial Number Identification ................. 2
Ordering Replacement Parts ................................ 2
Quin-Cip Oil............................................................ 2
Crankcase Lubricant Capacity.............................. 2
Crankshaft Group ................................................... 3
Crankcase Group ................................................... 4
Connecting Rod & Piston Groups ...................... 5-8
Cylinder & Head Groups .................................. 9-12
Control Piping Schematics ................................. 13
Pilot Valves .......................................................... 14
Pilot Valve Repair Kit .......................................... 14
Differential Setting Chart .................................... 14
Suction Valve Unloader Assemblies .................. 15
Decals ................................................................... 15
Overhaul Kit ......................................................... 16
Head Kit ................................................................ 16
Recommended Spare Parts................................ 16
Gasket Set ............................................................ 16
Typical Unit Repair Parts List ........................ 17-19
