Vee Packing Set, 5.50 Inch OD, 5.00 Inch ID, 1.13 Inch Height

Pressure range is what determines the vee ring count. Four vees gets you up to 3,000 PSI, five vees covers up to 5,000 PSI, and six vees handles up to 10,000 PSI. The set itself uses a combination of urethane and fabric-reinforced rubber vee rings along with nylon top and bottom adaptors. The code on the part breaks it down in order, quantity of top nylon adaptors, then urethane vee rings, then fabric vee rings, then bottom nylon adaptors. So if your system runs somewhere in the mid-range, five vees is probably your number, but anything pushing toward the upper end you'll want to go with six.