1.1 The dynamic seal groove type, size and tolerance specified in this standard are applicable to all kinds of seal rings installed on the piston and piston rod of the reciprocating hydraulic cylinder to perform unidirectional sealing.
GB/T 2879-1986 history
2005GB/T 2879-2005 Hydraulic fluid power-Cylinders-Housings for piston and rod seals in reciprocating applications-Dimensions and tolerances
1986GB/T 2879-1986 Hydraulic fluid power--Cylinder rod and piston seals for reciprocating applications--Dimensions and tolerances of housings