NFPA (Fluid) T3.19.11-1973 (R2012)
Groove dimensions for floating type metallic and non-metallic fluid power piston rings
standard by National Fluid Power Association, 12/05/1973
NFPA (Fluid) T3.6.8 R3-2007
Fluid Power Systems — Cylinders — Dimensions for Accessories for Catalogued Square Head Industrial Types
standard by National Fluid Power Association, 05/10/2007
NFPA (Fluid) T3.5.15M-1986 (R2018)
Hydraulic Fluid Power — Valves — Method for Determining the Internal Leakage Characteristics
standard by National Fluid Power Association, 06/04/1986