Pistons

Ceramaret manufactures high quality pistons in Sapphire, Ruby and TZP (Tetragonal Zirconia Polycrystalline) Zirconia (ZrO2) for HPLC pumps and precision liquid dispensers. The materials are inert and resistant to most solvents. Their extreme hardness combined with a perfect surface finish (Ra<0,025mm or 1 minch) insure minimum friction and maximum seal life.
Piston/Liner Sets

Ceramaret also manufactures piston / liner sets for metering pumps and valve applications. Adjustment between the piston and the cylinder is within 3 microns, insuring a leak free adjustment and maximum durability.
Shafts

Custom-made shafts in TZP zirconia (ZrO2) and in alumina ceramics (Al2O3) are also available. These are made from a range of blanks available from stock and finished upon request. These shafts, just as the pistons, can be delivered bare or mounted on a ferule to customer's specifications.
General Dimensions

Minimum


· Diameter 0,40 mm (.016") with length up to 30,00 mm (1,181").

· Diameter 0,50 mm (.020") with length up to 50,80 mm (2,000").

Maximum


· Diameter 25,40 mm (1,000") with length up to 150,00 mm (5,900").

General Tolerances


· OD ≥ +/- 0,005 mm (+/-.0002").

· Length +/- 0,100 mm (+/-.004").

Surface Finish


· N1 (<1 min) obtainable between diameter 0,50 mm (.020") by maximum length of 50,80 mm (2,000") and 10,00 mm (.394") by maximum length of 44,45 mm (6/16").

· N3 for diameters > 10,00 mm (.394") in zirconia.

· N4 for diameters > 10,00 mm (.394") in alumina.
Quality Assurance Procedure

Dimensions and Characteristic to be Tested


Test Equipment


AQL

Piston only







Piston diameter


Digital micrometer


0.25

Piston length


Caliper


0.25

Geometry of ends


Shadowgraph 20X


1.0

Roundness


Talyrond


1.5

Surface finish


Talysurf


n=3%

Groove (if any)


Shadowgraph 20X


1.0

Visual inspection for chips, cracks, internal and external defects


Binocular 25X


0.65%

Piston with ferule







Dimensions of the ferule


Micrometer and calliper


1.0

Length of the piston from a reference surface of the ferule


Vertical miocrometer


0.65

Length of the piston from a reference surface of the ferule


Maret test fixture


0.25

Resistance traction / compression


Maret assembly press


0.65

Pistons with ferule are assembled by cold press fitting giving:

· Optimal traction / compression resistance and maximum concentricity between both components (0,050 to 0,100 mm or .002" to .004").

· No distortion of the ferule and no thermal shock to both components, as opposed to fitting by heat shrinking.

· No needs for adhesives sensitive to chemical solvents
Piston Configurations

General Configuration available (one or both ends)