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

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.

What models can this kit be used with?

• CNEC Fixed-orifice, non-pressure compensated, flow control valve with reverse flow check
• CNFC Free flow nose to side check valve with bypass orifice
• CXED Free flow side to nose check valve
• CXFA Free flow nose to side check valve
• CXFHZ Free flow nose to side check valve with position switch
• DFDA
  2-way, 2-stage, solenoid-operated directional poppet valve - flow 1-2
• DFDA8 2-way, poppet directional valve with integral T-8A control cavity - control 1-2
• DFDB
  2-way, 2-stage, solenoid-operated directional poppet valve - flow 2-1
• DFDB8 2-way, poppet directional valve with integral T-8A control cavity - control 2-1
• FCDB Fixed-orifice pressure compensated flow control valve with reverse flow check
• FDCB Fully adjustable pressure compensated flow control valve with reverse flow check
• FLFA Filter
• FPFK Pilot-operated, normally closed, electro-proportional throttle with reverse flow check
• FQEA Fixed-orifice, flow fuse valve
• FXDA Fixed-orifice, pressure compensated flow control valve
• FXDA8 Ventable fixed-orifice, pressure compensated flow control valve with integral T-8A control cavity
• NCEB Fully adjustable needle valve with reverse flow check
• NCEC Fully adjustable needle valve with reverse flow check
• NFDC Fully adjustable needle valve
• NFDD Fully adjustable needle valve
• NQEB Air bleed and start-up valve
• RBAA Direct-acting relief valve - pilot capacity
• RBAB Air-controlled, direct-acting relief valve - pilot capacity
• RGFA Low-pressure-range, direct-acting relief valve
• 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
• SCEB Atmospherically referenced, direct-acting sequence valve with reverse flow check
• XCCA All ports blocked cavity plug
• XCOA All ports open cavity plug

• 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.

• Seal Kit Installation Guidelines
• Sun's Floating Style Screw-In Cartridge (1.06 MB)
• Seals: Materials of Construction