Series 2 - T-3A cavity and T-5A cavity, Polyurethane cartridge seal kit

990003002 : Series 2 - T-3A cavity and T-5A cavity, Polyurethane cartridge seal kit
Technical Features [ + ]

Sun offers replacement seal kits for all cartridge models. These kits include all of the external seals on the cartridge along with installation instructions. Seal kits are available in Buna-N and Viton for all models, along with EPDM and polyurethane for many models. Please note: Converting the external seals from one material to another does not ensure fluid compatibility with that material due to the existence of internal seals within the cartridge.

  • The shelf life for this cartridge seal kit is ten years from date of purchase. This date will be printed on the kit packaging.
  • The Series 2, two port cavity comes in two versions: the T-3A and the T-5A. The T-3A cavity is typically used in relief applications which require larger port areas, hence a deeper cavity. The T-5A cavity is typically used in flow control applications and utilizes a smaller port area. Since both cavities are Series 2, two port, they share common seal kits, but exclude the possibility of cartridge interchangeability between the two functions.
  • Polyurethane seals have a higher tensile strength and are more abrasion/extrusion resistant and are well suited for high cycle and high pressure applications.
Technical Data [ + ]
Series 2
Cartridge Thread 1"-14 UNS1"-14 UNS
Valve Hex Size 1 1/8 in.28,6 mm
Valve Installation Torque 45 - 50 lbf ft61 - 68 Nm
Cavity T-3A & T-5A
Used With [ + ]

What models can this kit be used with?

  • NQEB Air bleed and start-up valve
  • RBAA Direct-acting relief valve - pilot capacity
  • RPGC Pilot operated, balanced piston relief valve
  • RPGC8 Pilot operated, balanced piston relief main stage with integral T-8A control cavity
  • RPGD Air-controlled, pilot operated, balanced piston relief valve
  • RPGE Fast-acting, pilot operated, balanced piston relief valve
  • RQGB Kick-down, pilot operated, balanced piston relief valve
  • XCCA All ports blocked cavity plug
Notes [ + ]
  • Install back-up rings and O-rings as shown in views.
  • See installation variations for models associated with alternative installation views.
  • When installing continuous back-up rings, use the same technique and the same care used to install O-rings.
  • When installing cartridge - be sure to torque to recommended value.
  • During 1985, SUN made a running change of all external seals on Series 2 cartridges (1-1/8 in. (28,6 mm) hex, 1-14 thd). The seals were changed from 3/32 in. (2,62 mm) c/s to 1/16 in (1,7/8 mm) c/s o-rings and backup rings.
  • Use the kit which contains the same size (c/s) seals as those used on the cartridge being repaired. Do not change cartridge o-ring c/s sizes.
Additional Resources [ + ]