The Von Duprin 050428 is the OEM center case kit for the Von Duprin 88K/L-F exit device in RHR (Right Hand Reverse) handling, documented in the Von Duprin 88 Rim Parts Manual. It covers the 88K-F (fire-rated, outside knob trim) and 88L-F (fire-rated, outside lever trim) rim exit devices configured for Right Hand Reverse doors. Finish must be specified at time of order.

This center case kit is handing-specific. The 88 Rim device in EO, TP, and NL trim functions is field reversible - you can flip it in the field to accommodate different door handings. The K and L outside trim functions are not. The mechanical connection between the keyed outside knob or lever and the center case mechanism requires the case to be factory-oriented for the specific door handling. Order the 050428 for RHR doors only.

Why the 88K/L Center Case Is Handed

Most rim exit devices are non-handed - the device can be installed on doors of any handing by adjusting the latch orientation. The 88 Series EO, TP, and NL functions are all field reversible per the Von Duprin 88 Series Catalog.

The 88K and 88L functions with outside knob or lever trim are different. On an 88K, the key in the outside knob cylinder mechanically locks and unlocks the outside knob's connection to the latch mechanism. On an 88L, the key locks and unlocks the outside lever, which remains always operable when unlocked. That key-to-outside-trim-to-latch-mechanism chain requires the center case to be correctly oriented relative to the door swing direction to properly transmit motion from the trim through to the latch. Getting the handing wrong means the outside trim won't correctly engage the center case, and the latch won't operate as intended.

RHR stands for Right Hand Reverse - a door where the hinges are on the right when viewed from inside, and the door swings toward you (outward). Exit devices on outswing doors are standard in many commercial applications. If you're standing inside the room looking at the door and the hinges are on your right and the door swings away from the building when opened, that's RHR.

Von Duprin Center Case Kit: 88K/L-F Application

The 88K-F and 88L-F are the fire-rated versions of the 88 Series with outside knob or lever trim. The "-F" suffix confirms UL listing for Fire Exit Hardware in addition to the standard panic exit hardware listing. All 88 Series devices are UL listed for accident hazard installations and tested per ANSI A156.3, Grade 1. The fire-rated versions meet UL fire exit hardware requirements for fire-rated door assemblies.

The 88K function operates as follows: the outside knob is normally locked. The key in the outside cylinder locks or unlocks the knob. When unlocked, the outside knob retracts the latch. The inside lever is always free for egress - turning the inside lever retracts the latch regardless of outside knob state, which is the life safety requirement. When the outside knob is locked, it cannot retract the latch from outside, but egress from inside is never restricted.

The 88L function uses the same key-controlled mechanism but with a lever replacing the knob on the outside. Lever is always active when unlocked. Key locks or unlocks outside lever independently.

Von Duprin Exit Device Parts: Ordering the Correct 88K/L-F Center Case

The 050428 is the RHR center case kit. If the door is LHR (Left Hand Reverse - hinges on left when viewed from inside, outswing), a different center case kit applies. Confirm the exact handing before ordering. RHR and LHR center case kits are not interchangeable.

SecurityParts stocks OEM Von Duprin 88 Series exit device parts.