Patent ID: 6286837
Filing Date: 2001-09-11
Classification: F16J

Abstract:
In a packing for a piston rod of a gas compressor, a packing ring set comprisinga first split packing ring containing a first plurality of arcuately extending segments arranged to form a first annulus, wherein opposing ends of successive pairs of said segments each form a joint;a second split packing ring disposed next to and on a low pressure side of said first ring as measured during a piston rod compression stroke, said second ring containing a second plurality of arcuately extending segments arranged to form a second annulus, wherein opposing end portions of successive pairs of said segments each form a joint, said first and second rings being compressible on said piston rod at all gas pressures in a cylinder of said compressor which are less than a preselected intermediate value;a third uncut packing ring disposed next to and on a low pressure side of said second ring as measured during said piston rod compression stroke, said third ring being constructed of a non-metallic material and being compressible on said piston rod at all gas pressures in said cylinder which are equal to and greater than said intermediate value; anda fourth uncut packing ring disposed next to and on a low pressure side of said third ring, said fourth ring being constructed of a relatively less compressible material than is used to construct said third ring, said fourth ring being compressible on said piston rod along with said third ring at all gas pressures in said cylinder which are equal to and greater than a predetermined high value.