Design of Annular Piston - Length to Diameter Ratio 1

[dcoppo]

Need criteria for selection of piston length for an annular piston design. The ID is 10 inches and the maximum operating pressure is 7500 PSI. Plan on using PolyPac Seal system, but cannot find a reliable criteria for L/D ratio/piston anti-jam stability. Operation is subsea in 5000 to 10000 feet of water.

 

[Duwe6]

Take a look at diesel design. Just eyeballing the ratio, looks like 2-2.5:1 to me.

 

[hydtools]

1.5:1 or more. Check max. off-square angle for your max. tolerances, both ID and OD. Somewhat depends on running clearances; the greater the L, the greater the possible running clearances.

Ted

 

[btrueblood]

Careful you don't violate any patents...