Heavy Duty Balanced Opposed Compressors - Ariel Corporation

FOR MODELS: JGZ AND JGU SECTION 5 - MAINTENANCE
piston rod and remove.
6. As the piston leaves the cylinder, be careful in handling the piston rings. Despite
their toughness in service, rings are fragile with regard to removal. Always handle
them with clean tools and hands, and protect the rings from nicks, marring,
and bending. Move the piston out of the cylinder until a fraction of the first ring
clears the cylinder. Encircle the ring by hand (use a band for larger sizes) until it
is clear and remove it. Use this same procedure to remove the succeeding rings
and wear band.
7. Slide the piston rod out of the packing case and crank end head. The threaded
crosshead end of the rod is 1/4 inches (6 mm) smaller in diameter than the
inside diameter of the packing. Using extreme care, slowly slide the piston rod
through the packing so as not to damage the rod threads or the packing rings.
Piston and Rod - Disassembly and Reassembly
Piston and Rod - Disassembly
Clean the threaded hole in the end of the piston rod to remove any residue, corrosion, etc.
that may be present. Remove the piston nut set screws (2). Use the separately purchased
Hydraulic Piston Nut Torquing Tool and appropriate hand pump (reference Figure 5-26 on
Page 5-39 and the instructions in “Reassembly” below for detailed information to apply the
tool) to disassemble piston and rod.
!
Piston and Rod - Reassembly
CAUTION
TRAPPED GAS PRESSURE IN HOLLOW PISTONS CAN PRESENT A PERSONAL
SAFETY HAZARD WHEN SERVICING THE PISTON AND ROD ASSEMBLY. WORK
IN A WELL VENTILATED, NON SPARKING AREA. DO NOT BREATHE GAS EMIT-
TED FROM PISTONS WHEN VENTING TRAPPED GAS.
1. Clean all piston and rod assembly parts thoroughly. Be sure piston is internally
clean and dry.
2. Inspect parts for nicks, burrs or scratches and dress surfaces with a fine grit
stone as required.
3. Inspect the piston rod threads and collar shoulder. Threads are to be clean and
free of burrs. Fit the collar and nut into the piston to verify the outside diameter
fits and it rotates freely. Install the collar and nut onto the piston rod to verify that
the inside diameter fits and it rotates freely. Run the piston nut down by hand
until the rod threads protrude to verify freedom of thread engagement. Remove
nut and collar.
4. Check piston rings and wear band to determine wear (see “Determining Ring
Wear:” on Page 5-42 and “Determining Wear Band Wear:” on Page 5-42).
Replace piston rings and wear bands as required.
5. Apply a thin coating of “Never-Seez”, Regular Grade to the piston rod shoulder
7/09 PAGE 5 - 37