By Kent · Lock Depot Staff Writer

Von Duprin 990 Series Trim: NL, DT, or EO for a 98/99 Exit Device

The exit device on the door is fine. It's the outside that's the problem: no way back in, a broken lever, or a trim function that never matched what the building actually needed. Before anyone talks about replacing a whole Von Duprin 98 or 99 series exit device, check the trim first. Most of the time that's the actual fix, and it's a fraction of the cost.

Von Duprin's 990 series outside trim mounts straight onto an existing 98 or 99 rim exit device body. No pulling the device off the door, no re-templating a fire-rated opening. Get the function right and it bolts on in an hour.

What outside trim actually does

An exit device only handles one direction: push the bar, the door opens, egress is never blocked. That's code, full stop. Everything about how a person gets back in from the outside, the pull side, lives in the trim. No trim means no operable hardware out there at all, just a flat door face.

That's exactly why trim selection matters more than most people assume walking up to a 98 series door. Three functions cover almost every real job:

NL: night latch, for a door that needs regular reentry

The 990NL-RV is lever trim with a working cylinder or access-control credential. Someone with a key, or the right card at a reader, unlocks the outside lever and walks back in. This is the default for a back door that staff, delivery drivers, or after-hours tenants need to use both ways, all day.

If a customer is upgrading from an exit-only setup to lever trim, tell them up front: they need a cylinder or an SFIC core to finish the install. That's a separate line item people forget to budget until the trim shows up with a blank cylinder hole staring back at them.

DT: dummy trim, pull-when-dogged, no lock at all

The 990DT-US26D is a fixed lever that does not retract the latch and does not lock or unlock anything. It's cosmetic, mostly, except for one real function: when the exit device is dogged down (hex-key held open for business hours), the dummy lever gives someone on the outside a real handle to pull instead of clawing at a bare door edge.

Dummy trim shows up on doors where the building never wants outside reentry, period, but still wants a lever that looks intentional rather than a plain metal plate. Storage rooms, mechanical closets, back-of-house doors that lead nowhere useful to the public.

One thing to check before ordering: Von Duprin has run more than ten lever designs over the years, L-01 through L-18 and beyond, and they are not interchangeable without swapping the whole trim assembly. Get the lever number off the existing hardware, not a guess, before you place the order.

EO: exit only, the simplest and cheapest option

The 990EO-US26D isn't really trim at all. It's a flat plate. No lever, no cylinder, no way back in from outside under any circumstance. Free egress from inside, nothing to install on the pull side beyond a blank cover.

This is the right call for a stairwell door that only ever gets used going down in a fire, or a rear exit that exists purely to satisfy egress code and was never meant for daily foot traffic in both directions. No cylinder needed means one less thing to key, one less thing to fail, and the lowest price point in the 990 lineup.

The trim compatibility trap

Every one of these mounts specifically to the Von Duprin 98 series rim exit device body. None of it is cross-compatible with Sargent, Corbin Russwin, or any other manufacturer's exit device, even if the bar looks similar from across a hallway. Match trim to the exit device series first. If someone hands you a trim part number off a different brand's bar, stop and verify before ordering, because it will not mount.

Lever trim variants beyond the plain NL function exist too. The 996L-RV is one of them, a vertical-rod lever trim for the same 98/99 family, and the same lever-number rule applies before ordering a replacement.

I've seen a facilities manager order a full 99 series exit device to replace a bar that was working fine, because nobody checked whether the trim alone would solve the actual complaint. Half the time the complaint is "we can't get back in this door," and that's a trim job, not a device replacement. If you're starting from scratch on a hollow-metal fire door, read up on the 98/99 series exit device itself before picking a trim function to sit on top of it.

Common questions

Can I install 990 series trim myself without pulling the exit device off the door?

Yes. The trim mounts directly to the existing exit device body. That's the entire advantage over a full device swap; the bar stays on the door, the door doesn't get re-templated, and the labor is a fraction of what a new install runs.

What finish options are available on 990 series trim?

Satin chrome, US26D/626, is the standard commercial finish and the one that matches most existing Von Duprin hardware. Confirm the finish on the exit device itself before ordering trim, so the two don't clash on the door.

Do I need a cylinder with night latch (NL) trim?

Yes, for key override, or an access-control credential if it's wired into a reader. Neither ships installed. Order the cylinder or credential reader separately and specify the keyway if key override is needed.

Is dummy trim (DT) the same as no trim at all?

Functionally close, but not identical. DT gives the outside a fixed pull lever, useful when the device is dogged open during business hours. A bare EO plate gives nothing to grab at all.

Will any 990 series trim work on a fire-rated door?

Fire-rated openings have their own hardware and dogging restrictions under UL code; hex-key dogging in particular gets deleted on fire-rated models. Confirm the door's fire rating before ordering any trim function, since it can change which options are even legal to install.

Not sure which lever design or function code matches an existing 98/99 door? Browse the full Von Duprin line, or send the part number off the current bar and we'll match the trim exactly.